When more than one security module is exporting data to audit and networking sub-systems a single 32 bit integer is no longer sufficient to represent the data. Add a structure to be used instead. The lsmblob structure is currently an array of u32 "secids". There is an entry for each of the security modules built into the system that would use secids if active. The system assigns the module a "slot" when it registers hooks. If modules are compiled in but not registered there will be unused slots. A new lsm_id structure, which contains the name of the LSM and its slot number, is created. There is an instance for each LSM, which assigns the name and passes it to the infrastructure to set the slot. The audit rules data is expanded to use an array of security module data rather than a single instance. Because IMA uses the audit rule functions it is affected as well. Acked-by: Stephen Smalley <sds(a)tycho.nsa.gov&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Acked-by: John Johansen <john.johansen(a)canonical.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: <bpf(a)vger.kernel.org&gt; Cc: linux-audit(a)redhat.com Cc: linux-security-module(a)vger.kernel.org Cc: selinux(a)vger.kernel.org To: Mimi Zohar <zohar(a)linux.ibm.com&gt; --- include/linux/audit.h | 4 +- include/linux/lsm_hooks.h | 12 ++++- include/linux/security.h | 67 +++++++++++++++++++++++++-- kernel/auditfilter.c | 24 +++++----- kernel/auditsc.c | 12 ++--- security/apparmor/lsm.c | 7 ++- security/bpf/hooks.c | 12 ++++- security/commoncap.c | 7 ++- security/integrity/ima/ima_policy.c | 40 +++++++++++----- security/loadpin/loadpin.c | 8 +++- security/lockdown/lockdown.c | 7 ++- security/safesetid/lsm.c | 8 +++- security/security.c | 72 ++++++++++++++++++++++++----- security/selinux/hooks.c | 8 +++- security/smack/smack_lsm.c | 7 ++- security/tomoyo/tomoyo.c | 8 +++- security/yama/yama_lsm.c | 7 ++- 17 files changed, 254 insertions(+), 56 deletions(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index 82b7c1116a85..418a485af114 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -11,6 +11,7 @@ #include <linux/sched.h> #include <linux/ptrace.h> +#include <linux/security.h> #include <uapi/linux/audit.h> #include <uapi/linux/netfilter/nf_tables.h> @@ -65,8 +66,9 @@ struct audit_field { kuid_t uid; kgid_t gid; struct { + bool lsm_isset; char *lsm_str; - void *lsm_rule; + void *lsm_rules[LSMBLOB_ENTRIES]; }; }; u32 op; diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index f351863663b8..fb32b502080b 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1545,6 +1545,14 @@ struct security_hook_heads { #undef LSM_HOOK } __randomize_layout; +/* + * Information that identifies a security module. + */ +struct lsm_id { + const char *lsm; /* Name of the LSM */ + int slot; /* Slot in lsmblob if one is allocated */ +}; + /* * Security module hook list structure. * For use with generic list macros for common operations. @@ -1553,7 +1561,7 @@ struct security_hook_list { struct hlist_node list; struct hlist_head *head; union security_list_options hook; - char *lsm; + struct lsm_id *lsmid; } __randomize_layout; /* @@ -1588,7 +1596,7 @@ extern struct security_hook_heads security_hook_heads; extern char *lsm_names; extern void security_add_hooks(struct security_hook_list *hooks, int count, - char *lsm); + struct lsm_id *lsmid); #define LSM_FLAG_LEGACY_MAJOR BIT(0) #define LSM_FLAG_EXCLUSIVE BIT(1) diff --git a/include/linux/security.h b/include/linux/security.h index c35ea0ffccd9..4a109092a8d7 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -133,6 +133,65 @@ enum lockdown_reason { extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1]; +/* + * Data exported by the security modules + * + * Any LSM that provides secid or secctx based hooks must be included. + */ +#define LSMBLOB_ENTRIES ( \ + (IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_BPF_LSM) ? 1 : 0)) + +struct lsmblob { + u32 secid[LSMBLOB_ENTRIES]; +}; + +#define LSMBLOB_INVALID -1 /* Not a valid LSM slot number */ +#define LSMBLOB_NEEDED -2 /* Slot requested on initialization */ +#define LSMBLOB_NOT_NEEDED -3 /* Slot not requested */ + +/** + * lsmblob_init - initialize an lsmblob structure + * @blob: Pointer to the data to initialize + * @secid: The initial secid value + * + * Set all secid for all modules to the specified value. + */ +static inline void lsmblob_init(struct lsmblob *blob, u32 secid) +{ + int i; + + for (i = 0; i < LSMBLOB_ENTRIES; i++) + blob->secid[i] = secid; +} + +/** + * lsmblob_is_set - report if there is an value in the lsmblob + * @blob: Pointer to the exported LSM data + * + * Returns true if there is a secid set, false otherwise + */ +static inline bool lsmblob_is_set(struct lsmblob *blob) +{ + struct lsmblob empty = {}; + + return !!memcmp(blob, &empty, sizeof(*blob)); +} + +/** + * lsmblob_equal - report if the two lsmblob's are equal + * @bloba: Pointer to one LSM data + * @blobb: Pointer to the other LSM data + * + * Returns true if all entries in the two are equal, false otherwise + */ +static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb) +{ + return !memcmp(bloba, blobb, sizeof(*bloba)); +} + /* These functions are in security/commoncap.c */ extern int cap_capable(const struct cred *cred, struct user_namespace *ns, int cap, unsigned int opts); @@ -1839,8 +1898,8 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer) #ifdef CONFIG_SECURITY int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule); int security_audit_rule_known(struct audit_krule *krule); -int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule); -void security_audit_rule_free(void *lsmrule); +int security_audit_rule_match(u32 secid, u32 field, u32 op, void **lsmrule); +void security_audit_rule_free(void **lsmrule); #else @@ -1856,12 +1915,12 @@ static inline int security_audit_rule_known(struct audit_krule *krule) } static inline int security_audit_rule_match(u32 secid, u32 field, u32 op, - void *lsmrule) + void **lsmrule) { return 0; } -static inline void security_audit_rule_free(void *lsmrule) +static inline void security_audit_rule_free(void **lsmrule) { } #endif /* CONFIG_SECURITY */ diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index 333b3bcfc545..45da229f9f1f 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -74,7 +74,7 @@ static void audit_free_lsm_field(struct audit_field *f) case AUDIT_OBJ_LEV_LOW: case AUDIT_OBJ_LEV_HIGH: kfree(f->lsm_str); - security_audit_rule_free(f->lsm_rule); + security_audit_rule_free(f->lsm_rules); } } @@ -519,9 +519,10 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, goto exit_free; } entry->rule.buflen += f_val; + f->lsm_isset = true; f->lsm_str = str; err = security_audit_rule_init(f->type, f->op, str, - (void **)&f->lsm_rule); + f->lsm_rules); /* Keep currently invalid fields around in case they * become valid after a policy reload. */ if (err == -EINVAL) { @@ -774,7 +775,7 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) return 0; } -/* Duplicate LSM field information. The lsm_rule is opaque, so must be +/* Duplicate LSM field information. The lsm_rules is opaque, so must be * re-initialized. */ static inline int audit_dupe_lsm_field(struct audit_field *df, struct audit_field *sf) @@ -788,9 +789,9 @@ static inline int audit_dupe_lsm_field(struct audit_field *df, return -ENOMEM; df->lsm_str = lsm_str; - /* our own (refreshed) copy of lsm_rule */ + /* our own (refreshed) copy of lsm_rules */ ret = security_audit_rule_init(df->type, df->op, df->lsm_str, - (void **)&df->lsm_rule); + df->lsm_rules); /* Keep currently invalid fields around in case they * become valid after a policy reload. */ if (ret == -EINVAL) { @@ -842,7 +843,7 @@ struct audit_entry *audit_dupe_rule(struct audit_krule *old) new->tree = old->tree; memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount); - /* deep copy this information, updating the lsm_rule fields, because + /* deep copy this information, updating the lsm_rules fields, because * the originals will all be freed when the old rule is freed. */ for (i = 0; i < fcount; i++) { switch (new->fields[i].type) { @@ -1358,10 +1359,11 @@ int audit_filter(int msgtype, unsigned int listtype) case AUDIT_SUBJ_TYPE: case AUDIT_SUBJ_SEN: case AUDIT_SUBJ_CLR: - if (f->lsm_rule) { + if (f->lsm_isset) { security_task_getsecid(current, &sid); result = security_audit_rule_match(sid, - f->type, f->op, f->lsm_rule); + f->type, f->op, + f->lsm_rules); } break; case AUDIT_EXE: @@ -1388,7 +1390,7 @@ int audit_filter(int msgtype, unsigned int listtype) return ret; } -static int update_lsm_rule(struct audit_krule *r) +static int update_lsm_rules(struct audit_krule *r) { struct audit_entry *entry = container_of(r, struct audit_entry, rule); struct audit_entry *nentry; @@ -1420,7 +1422,7 @@ static int update_lsm_rule(struct audit_krule *r) return err; } -/* This function will re-initialize the lsm_rule field of all applicable rules. +/* This function will re-initialize the lsm_rules field of all applicable rules. * It will traverse the filter lists serarching for rules that contain LSM * specific filter fields. When such a rule is found, it is copied, the * LSM field is re-initialized, and the old rule is replaced with the @@ -1435,7 +1437,7 @@ int audit_update_lsm_rules(void) for (i = 0; i < AUDIT_NR_FILTERS; i++) { list_for_each_entry_safe(r, n, &audit_rules_list[i], list) { - int res = update_lsm_rule(r); + int res = update_lsm_rules(r); if (!err) err = res; } diff --git a/kernel/auditsc.c b/kernel/auditsc.c index ce8c9e2279ba..9eea55525480 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -665,14 +665,14 @@ static int audit_filter_rules(struct task_struct *tsk, match for now to avoid losing information that may be wanted. An error message will also be logged upon error */ - if (f->lsm_rule) { + if (f->lsm_isset) { if (need_sid) { security_task_getsecid(tsk, &sid); need_sid = 0; } result = security_audit_rule_match(sid, f->type, f->op, - f->lsm_rule); + f->lsm_rules); } break; case AUDIT_OBJ_USER: @@ -682,21 +682,21 @@ static int audit_filter_rules(struct task_struct *tsk, case AUDIT_OBJ_LEV_HIGH: /* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR also applies here */ - if (f->lsm_rule) { + if (f->lsm_isset) { /* Find files that match */ if (name) { result = security_audit_rule_match( name->osid, f->type, f->op, - f->lsm_rule); + f->lsm_rules); } else if (ctx) { list_for_each_entry(n, &ctx->names_list, list) { if (security_audit_rule_match( n->osid, f->type, f->op, - f->lsm_rule)) { + f->lsm_rules)) { ++result; break; } @@ -707,7 +707,7 @@ static int audit_filter_rules(struct task_struct *tsk, break; if (security_audit_rule_match(ctx->ipc.osid, f->type, f->op, - f->lsm_rule)) + f->lsm_rules)) ++result; } break; diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 41778ff0c67c..1dfb8648136e 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -1152,6 +1152,11 @@ struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = { .lbs_sock = sizeof(struct aa_sk_ctx), }; +static struct lsm_id apparmor_lsmid __lsm_ro_after_init = { + .lsm = "apparmor", + .slot = LSMBLOB_NEEDED +}; + static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check), LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme), @@ -1852,7 +1857,7 @@ static int __init apparmor_init(void) goto buffers_out; } security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks), - "apparmor"); + &apparmor_lsmid); /* Report that AppArmor successfully initialized */ apparmor_initialized = 1; diff --git a/security/bpf/hooks.c b/security/bpf/hooks.c index e5971fa74fd7..7a58fe9ab8c4 100644 --- a/security/bpf/hooks.c +++ b/security/bpf/hooks.c @@ -15,9 +15,19 @@ static struct security_hook_list bpf_lsm_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(task_free, bpf_task_storage_free), }; +/* + * slot has to be LSMBLOB_NEEDED because some of the hooks + * supplied by this module require a slot. + */ +struct lsm_id bpf_lsmid __lsm_ro_after_init = { + .lsm = "bpf", + .slot = LSMBLOB_NEEDED +}; + static int __init bpf_lsm_init(void) { - security_add_hooks(bpf_lsm_hooks, ARRAY_SIZE(bpf_lsm_hooks), "bpf"); + security_add_hooks(bpf_lsm_hooks, ARRAY_SIZE(bpf_lsm_hooks), + &bpf_lsmid); pr_info("LSM support for eBPF active\n"); return 0; } diff --git a/security/commoncap.c b/security/commoncap.c index bacc1111d871..e85237ecb290 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -1340,6 +1340,11 @@ int cap_mmap_file(struct file *file, unsigned long reqprot, #ifdef CONFIG_SECURITY +static struct lsm_id capability_lsmid __lsm_ro_after_init = { + .lsm = "capability", + .slot = LSMBLOB_NOT_NEEDED +}; + static struct security_hook_list capability_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(capable, cap_capable), LSM_HOOK_INIT(settime, cap_settime), @@ -1364,7 +1369,7 @@ static struct security_hook_list capability_hooks[] __lsm_ro_after_init = { static int __init capability_init(void) { security_add_hooks(capability_hooks, ARRAY_SIZE(capability_hooks), - "capability"); + &capability_lsmid); return 0; } diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 823a0c1379cb..8002683003e6 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -79,7 +79,7 @@ struct ima_rule_entry { bool (*fowner_op)(kuid_t, kuid_t); /* uid_eq(), uid_gt(), uid_lt() */ int pcr; struct { - void *rule; /* LSM file metadata specific */ + void *rules[LSMBLOB_ENTRIES]; /* LSM file metadata specific */ char *args_p; /* audit value */ int type; /* audit type */ } lsm[MAX_LSM_RULES]; @@ -88,6 +88,22 @@ struct ima_rule_entry { struct ima_template_desc *template; }; +/** + * ima_lsm_isset - Is a rule set for any of the active security modules + * @rules: The set of IMA rules to check + * + * If a rule is set for any LSM return true, otherwise return false. + */ +static inline bool ima_lsm_isset(void *rules[]) +{ + int i; + + for (i = 0; i < LSMBLOB_ENTRIES; i++) + if (rules[i]) + return true; + return false; +} + /* * Without LSM specific knowledge, the default policy can only be * written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner @@ -326,9 +342,11 @@ static void ima_free_rule_opt_list(struct ima_rule_opt_list *opt_list) static void ima_lsm_free_rule(struct ima_rule_entry *entry) { int i; + int r; for (i = 0; i < MAX_LSM_RULES; i++) { - ima_filter_rule_free(entry->lsm[i].rule); + for (r = 0; r < LSMBLOB_ENTRIES; r++) + ima_filter_rule_free(entry->lsm[i].rules[r]); kfree(entry->lsm[i].args_p); } } @@ -379,8 +397,8 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry) ima_filter_rule_init(nentry->lsm[i].type, Audit_equal, nentry->lsm[i].args_p, - &nentry->lsm[i].rule); - if (!nentry->lsm[i].rule) + &nentry->lsm[i].rules[0]); + if (!ima_lsm_isset(nentry->lsm[i].rules)) pr_warn("rule for LSM \'%s\' is undefined\n", nentry->lsm[i].args_p); } @@ -545,7 +563,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, int rc = 0; u32 osid; - if (!rule->lsm[i].rule) { + if (!ima_lsm_isset(rule->lsm[i].rules)) { if (!rule->lsm[i].args_p) continue; else @@ -558,14 +576,14 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, security_inode_getsecid(inode, &osid); rc = ima_filter_rule_match(osid, rule->lsm[i].type, Audit_equal, - rule->lsm[i].rule); + rule->lsm[i].rules); break; case LSM_SUBJ_USER: case LSM_SUBJ_ROLE: case LSM_SUBJ_TYPE: rc = ima_filter_rule_match(secid, rule->lsm[i].type, Audit_equal, - rule->lsm[i].rule); + rule->lsm[i].rules); default: break; } @@ -952,7 +970,7 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry, { int result; - if (entry->lsm[lsm_rule].rule) + if (ima_lsm_isset(entry->lsm[lsm_rule].rules)) return -EINVAL; entry->lsm[lsm_rule].args_p = match_strdup(args); @@ -962,8 +980,8 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry, entry->lsm[lsm_rule].type = audit_type; result = ima_filter_rule_init(entry->lsm[lsm_rule].type, Audit_equal, entry->lsm[lsm_rule].args_p, - &entry->lsm[lsm_rule].rule); - if (!entry->lsm[lsm_rule].rule) { + &entry->lsm[lsm_rule].rules[0]); + if (!ima_lsm_isset(entry->lsm[lsm_rule].rules)) { pr_warn("rule for LSM \'%s\' is undefined\n", entry->lsm[lsm_rule].args_p); @@ -1733,7 +1751,7 @@ int ima_policy_show(struct seq_file *m, void *v) } for (i = 0; i < MAX_LSM_RULES; i++) { - if (entry->lsm[i].rule) { + if (ima_lsm_isset(entry->lsm[i].rules)) { switch (i) { case LSM_OBJ_USER: seq_printf(m, pt(Opt_obj_user), diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c index b12f7d986b1e..b569f3bc170b 100644 --- a/security/loadpin/loadpin.c +++ b/security/loadpin/loadpin.c @@ -192,6 +192,11 @@ static int loadpin_load_data(enum kernel_load_data_id id, bool contents) return loadpin_read_file(NULL, (enum kernel_read_file_id) id, contents); } +static struct lsm_id loadpin_lsmid __lsm_ro_after_init = { + .lsm = "loadpin", + .slot = LSMBLOB_NOT_NEEDED +}; + static struct security_hook_list loadpin_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(sb_free_security, loadpin_sb_free_security), LSM_HOOK_INIT(kernel_read_file, loadpin_read_file), @@ -239,7 +244,8 @@ static int __init loadpin_init(void) pr_info("ready to pin (currently %senforcing)\n", enforce ? "" : "not "); parse_exclude(); - security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks), "loadpin"); + security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks), + &loadpin_lsmid); return 0; } diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c index 87cbdc64d272..4e24ea3f7b7e 100644 --- a/security/lockdown/lockdown.c +++ b/security/lockdown/lockdown.c @@ -75,6 +75,11 @@ static struct security_hook_list lockdown_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(locked_down, lockdown_is_locked_down), }; +static struct lsm_id lockdown_lsmid __lsm_ro_after_init = { + .lsm = "lockdown", + .slot = LSMBLOB_NOT_NEEDED +}; + static int __init lockdown_lsm_init(void) { #if defined(CONFIG_LOCK_DOWN_KERNEL_FORCE_INTEGRITY) @@ -83,7 +88,7 @@ static int __init lockdown_lsm_init(void) lock_kernel_down("Kernel configuration", LOCKDOWN_CONFIDENTIALITY_MAX); #endif security_add_hooks(lockdown_hooks, ARRAY_SIZE(lockdown_hooks), - "lockdown"); + &lockdown_lsmid); return 0; } diff --git a/security/safesetid/lsm.c b/security/safesetid/lsm.c index 8a176b6adbe5..7c7ac9bfe5cd 100644 --- a/security/safesetid/lsm.c +++ b/security/safesetid/lsm.c @@ -244,6 +244,11 @@ static int safesetid_task_fix_setgid(struct cred *new, return -EACCES; } +static struct lsm_id safesetid_lsmid __lsm_ro_after_init = { + .lsm = "safesetid", + .slot = LSMBLOB_NOT_NEEDED +}; + static struct security_hook_list safesetid_security_hooks[] = { LSM_HOOK_INIT(task_fix_setuid, safesetid_task_fix_setuid), LSM_HOOK_INIT(task_fix_setgid, safesetid_task_fix_setgid), @@ -253,7 +258,8 @@ static struct security_hook_list safesetid_security_hooks[] = { static int __init safesetid_security_init(void) { security_add_hooks(safesetid_security_hooks, - ARRAY_SIZE(safesetid_security_hooks), "safesetid"); + ARRAY_SIZE(safesetid_security_hooks), + &safesetid_lsmid); /* Report that SafeSetID successfully initialized */ safesetid_initialized = 1; diff --git a/security/security.c b/security/security.c index 4b456b5f8096..39dce9eb3bcd 100644 --- a/security/security.c +++ b/security/security.c @@ -342,6 +342,7 @@ static void __init ordered_lsm_init(void) init_debug("msg_msg blob size = %d\n", blob_sizes.lbs_msg_msg); init_debug("sock blob size = %d\n", blob_sizes.lbs_sock); init_debug("task blob size = %d\n", blob_sizes.lbs_task); + init_debug("lsmblob size = %zu\n", sizeof(struct lsmblob)); /* * Create any kmem_caches needed for blobs @@ -469,21 +470,36 @@ static int lsm_append(const char *new, char **result) return 0; } +/* + * Current index to use while initializing the lsmblob secid list. + */ +static int lsm_slot __lsm_ro_after_init; + /** * security_add_hooks - Add a modules hooks to the hook lists. * @hooks: the hooks to add * @count: the number of hooks to add - * @lsm: the name of the security module + * @lsmid: the identification information for the security module * * Each LSM has to register its hooks with the infrastructure. + * If the LSM is using hooks that export secids allocate a slot + * for it in the lsmblob. */ void __init security_add_hooks(struct security_hook_list *hooks, int count, - char *lsm) + struct lsm_id *lsmid) { int i; + if (lsmid->slot == LSMBLOB_NEEDED) { + if (lsm_slot >= LSMBLOB_ENTRIES) + panic("%s Too many LSMs registered.\n", __func__); + lsmid->slot = lsm_slot++; + init_debug("%s assigned lsmblob slot %d\n", lsmid->lsm, + lsmid->slot); + } + for (i = 0; i < count; i++) { - hooks[i].lsm = lsm; + hooks[i].lsmid = lsmid; hlist_add_tail_rcu(&hooks[i].list, hooks[i].head); } @@ -492,7 +508,7 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count, * and fix this up afterwards. */ if (slab_is_available()) { - if (lsm_append(lsm, &lsm_names) < 0) + if (lsm_append(lsmid->lsm, &lsm_names) < 0) panic("%s - Cannot get early memory.\n", __func__); } } @@ -2006,7 +2022,7 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name, struct security_hook_list *hp; hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) { - if (lsm != NULL && strcmp(lsm, hp->lsm)) + if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm)) continue; return hp->hook.getprocattr(p, name, value); } @@ -2019,7 +2035,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value, struct security_hook_list *hp; hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) { - if (lsm != NULL && strcmp(lsm, hp->lsm)) + if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm)) continue; return hp->hook.setprocattr(name, value, size); } @@ -2512,7 +2528,24 @@ int security_key_getsecurity(struct key *key, char **_buffer) int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule) { - return call_int_hook(audit_rule_init, 0, field, op, rulestr, lsmrule); + struct security_hook_list *hp; + bool one_is_good = false; + int rc = 0; + int trc; + + hlist_for_each_entry(hp, &security_hook_heads.audit_rule_init, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + trc = hp->hook.audit_rule_init(field, op, rulestr, + &lsmrule[hp->lsmid->slot]); + if (trc == 0) + one_is_good = true; + else + rc = trc; + } + if (one_is_good) + return 0; + return rc; } int security_audit_rule_known(struct audit_krule *krule) @@ -2520,14 +2553,31 @@ int security_audit_rule_known(struct audit_krule *krule) return call_int_hook(audit_rule_known, 0, krule); } -void security_audit_rule_free(void *lsmrule) +void security_audit_rule_free(void **lsmrule) { - call_void_hook(audit_rule_free, lsmrule); + struct security_hook_list *hp; + + hlist_for_each_entry(hp, &security_hook_heads.audit_rule_free, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + hp->hook.audit_rule_free(lsmrule[hp->lsmid->slot]); + } } -int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule) +int security_audit_rule_match(u32 secid, u32 field, u32 op, void **lsmrule) { - return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule); + struct security_hook_list *hp; + int rc; + + hlist_for_each_entry(hp, &security_hook_heads.audit_rule_match, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + rc = hp->hook.audit_rule_match(secid, field, op, + &lsmrule[hp->lsmid->slot]); + if (rc) + return rc; + } + return 0; } #endif /* CONFIG_AUDIT */ diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index d500a09c8cbd..49f721511b55 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -6941,6 +6941,11 @@ static int selinux_perf_event_write(struct perf_event *event) } #endif +static struct lsm_id selinux_lsmid __lsm_ro_after_init = { + .lsm = "selinux", + .slot = LSMBLOB_NEEDED +}; + /* * IMPORTANT NOTE: When adding new hooks, please be careful to keep this order: * 1. any hooks that don't belong to (2.) or (3.) below, @@ -7252,7 +7257,8 @@ static __init int selinux_init(void) hashtab_cache_init(); - security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux"); + security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), + &selinux_lsmid); if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET)) panic("SELinux: Unable to register AVC netcache callback\n"); diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 6468fe4ad755..010f97c703aa 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -4692,6 +4692,11 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = { .lbs_sock = sizeof(struct socket_smack), }; +static struct lsm_id smack_lsmid __lsm_ro_after_init = { + .lsm = "smack", + .slot = LSMBLOB_NEEDED +}; + static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check), LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme), @@ -4891,7 +4896,7 @@ static __init int smack_init(void) /* * Register with LSM */ - security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack"); + security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), &smack_lsmid); smack_enabled = 1; pr_info("Smack: Initializing.\n"); diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c index 1f3cd432d830..22f62c67f2ec 100644 --- a/security/tomoyo/tomoyo.c +++ b/security/tomoyo/tomoyo.c @@ -523,6 +523,11 @@ static void tomoyo_task_free(struct task_struct *task) } } +static struct lsm_id tomoyo_lsmid __lsm_ro_after_init = { + .lsm = "tomoyo", + .slot = LSMBLOB_NOT_NEEDED +}; + /* * tomoyo_security_ops is a "struct security_operations" which is used for * registering TOMOYO. @@ -575,7 +580,8 @@ static int __init tomoyo_init(void) struct tomoyo_task *s = tomoyo_task(current); /* register ourselves with the security framework */ - security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), "tomoyo"); + security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), + &tomoyo_lsmid); pr_info("TOMOYO Linux initialized\n"); s->domain_info = &tomoyo_kernel_domain; atomic_inc(&tomoyo_kernel_domain.users); diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c index 06e226166aab..a9639ea541f7 100644 --- a/security/yama/yama_lsm.c +++ b/security/yama/yama_lsm.c @@ -421,6 +421,11 @@ static int yama_ptrace_traceme(struct task_struct *parent) return rc; } +static struct lsm_id yama_lsmid __lsm_ro_after_init = { + .lsm = "yama", + .slot = LSMBLOB_NOT_NEEDED +}; + static struct security_hook_list yama_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(ptrace_access_check, yama_ptrace_access_check), LSM_HOOK_INIT(ptrace_traceme, yama_ptrace_traceme), @@ -477,7 +482,7 @@ static inline void yama_init_sysctl(void) { } static int __init yama_init(void) { pr_info("Yama: becoming mindful.\n"); - security_add_hooks(yama_hooks, ARRAY_SIZE(yama_hooks), "yama"); + security_add_hooks(yama_hooks, ARRAY_SIZE(yama_hooks), &yama_lsmid); yama_init_sysctl(); return 0; } -- 2.25.4

Integrity measurement may filter on security module information and needs to be clear in the case of multiple active security modules which applies. Provide a boot option ima_rules_lsm= to allow the user to specify an active securty module to apply filters to. If not specified, use the first registered module that supports the audit_rule_match() LSM hook. Allow the user to specify in the IMA policy an lsm= option to specify the security module to use for a particular rule. Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; To: Mimi Zohar <zohar(a)linux.ibm.com&gt; To: linux-integrity(a)vger.kernel.org --- Documentation/ABI/testing/ima_policy | 8 +++- security/integrity/ima/ima_policy.c | 64 ++++++++++++++++++++++------ 2 files changed, 57 insertions(+), 15 deletions(-) diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index e35263f97fc1..a7943d40466f 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -25,7 +25,7 @@ Description: base: [[func=] [mask=] [fsmagic=] [fsuuid=] [uid=] [euid=] [fowner=] [fsname=]] lsm: [[subj_user=] [subj_role=] [subj_type=] - [obj_user=] [obj_role=] [obj_type=]] + [obj_user=] [obj_role=] [obj_type=] [lsm=]] option: [[appraise_type=]] [template=] [permit_directio] [appraise_flag=] [keyrings=] base: @@ -114,6 +114,12 @@ Description: measure subj_user=_ func=FILE_CHECK mask=MAY_READ + It is possible to explicitly specify which security + module a rule applies to using lsm=. If the security + modules specified is not active on the system the rule + will be rejected. If lsm= is not specified the first + security module registered on the system will be assumed. + Example of measure rules using alternate PCRs:: measure func=KEXEC_KERNEL_CHECK pcr=4 diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 8002683003e6..de72b719c90c 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -82,6 +82,7 @@ struct ima_rule_entry { void *rules[LSMBLOB_ENTRIES]; /* LSM file metadata specific */ char *args_p; /* audit value */ int type; /* audit type */ + int which_lsm; /* which of the rules to use */ } lsm[MAX_LSM_RULES]; char *fsname; struct ima_rule_opt_list *keyrings; /* Measure keys added to these keyrings */ @@ -90,17 +91,15 @@ struct ima_rule_entry { /** * ima_lsm_isset - Is a rule set for any of the active security modules - * @rules: The set of IMA rules to check + * @entry: the rule entry to examine + * @lsm_rule: the specific rule type in question * - * If a rule is set for any LSM return true, otherwise return false. + * If a rule is set return true, otherwise return false. */ -static inline bool ima_lsm_isset(void *rules[]) +static inline bool ima_lsm_isset(struct ima_rule_entry *entry, int lsm_rule) { - int i; - - for (i = 0; i < LSMBLOB_ENTRIES; i++) - if (rules[i]) - return true; + if (entry->lsm[lsm_rule].rules[entry->lsm[lsm_rule].which_lsm]) + return true; return false; } @@ -273,6 +272,20 @@ static int __init default_appraise_policy_setup(char *str) } __setup("ima_appraise_tcb", default_appraise_policy_setup); +static int ima_rule_lsm __ro_after_init; + +static int __init ima_rule_lsm_init(char *str) +{ + ima_rule_lsm = lsm_name_to_slot(str); + if (ima_rule_lsm < 0) { + ima_rule_lsm = 0; + pr_err("rule lsm \"%s\" not registered", str); + } + + return 1; +} +__setup("ima_rule_lsm=", ima_rule_lsm_init); + static struct ima_rule_opt_list *ima_alloc_rule_opt_list(const substring_t *src) { struct ima_rule_opt_list *opt_list; @@ -346,7 +359,8 @@ static void ima_lsm_free_rule(struct ima_rule_entry *entry) for (i = 0; i < MAX_LSM_RULES; i++) { for (r = 0; r < LSMBLOB_ENTRIES; r++) - ima_filter_rule_free(entry->lsm[i].rules[r]); + if (entry->lsm[i].rules[r]) + ima_filter_rule_free(entry->lsm[i].rules[r]); kfree(entry->lsm[i].args_p); } } @@ -398,7 +412,7 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry) ima_filter_rule_init(nentry->lsm[i].type, Audit_equal, nentry->lsm[i].args_p, &nentry->lsm[i].rules[0]); - if (!ima_lsm_isset(nentry->lsm[i].rules)) + if (!ima_lsm_isset(nentry, i)) pr_warn("rule for LSM \'%s\' is undefined\n", nentry->lsm[i].args_p); } @@ -563,7 +577,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, int rc = 0; u32 osid; - if (!ima_lsm_isset(rule->lsm[i].rules)) { + if (!ima_lsm_isset(rule, i)) { if (!rule->lsm[i].args_p) continue; else @@ -925,6 +939,7 @@ enum { Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt, Opt_appraise_type, Opt_appraise_flag, Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings, + Opt_lsm, Opt_err }; @@ -962,6 +977,7 @@ static const match_table_t policy_tokens = { {Opt_pcr, "pcr=%s"}, {Opt_template, "template=%s"}, {Opt_keyrings, "keyrings=%s"}, + {Opt_lsm, "lsm=%s"}, {Opt_err, NULL} }; @@ -970,7 +986,7 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry, { int result; - if (ima_lsm_isset(entry->lsm[lsm_rule].rules)) + if (ima_lsm_isset(entry, lsm_rule)) return -EINVAL; entry->lsm[lsm_rule].args_p = match_strdup(args); @@ -981,7 +997,7 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry, result = ima_filter_rule_init(entry->lsm[lsm_rule].type, Audit_equal, entry->lsm[lsm_rule].args_p, &entry->lsm[lsm_rule].rules[0]); - if (!ima_lsm_isset(entry->lsm[lsm_rule].rules)) { + if (!ima_lsm_isset(entry, lsm_rule)) { pr_warn("rule for LSM \'%s\' is undefined\n", entry->lsm[lsm_rule].args_p); @@ -1488,6 +1504,19 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) &(template_desc->num_fields)); entry->template = template_desc; break; + case Opt_lsm: + result = lsm_name_to_slot(args[0].from); + if (result == LSMBLOB_INVALID) { + int i; + + for (i = 0; i < MAX_LSM_RULES; i++) + entry->lsm[i].args_p = NULL; + result = -EINVAL; + break; + } + entry->lsm->which_lsm = result; + result = 0; + break; case Opt_err: ima_log_string(ab, "UNKNOWN", p); result = -EINVAL; @@ -1524,6 +1553,7 @@ ssize_t ima_parse_add_rule(char *rule) struct ima_rule_entry *entry; ssize_t result, len; int audit_info = 0; + int i; p = strsep(&rule, "\n"); len = strlen(p) + 1; @@ -1541,6 +1571,9 @@ ssize_t ima_parse_add_rule(char *rule) INIT_LIST_HEAD(&entry->list); + for (i = 0; i < MAX_LSM_RULES; i++) + entry->lsm[i].which_lsm = ima_rule_lsm; + result = ima_parse_rule(p, entry); if (result) { ima_free_rule(entry); @@ -1751,7 +1784,7 @@ int ima_policy_show(struct seq_file *m, void *v) } for (i = 0; i < MAX_LSM_RULES; i++) { - if (ima_lsm_isset(entry->lsm[i].rules)) { + if (ima_lsm_isset(entry, i)) { switch (i) { case LSM_OBJ_USER: seq_printf(m, pt(Opt_obj_user), @@ -1793,6 +1826,9 @@ int ima_policy_show(struct seq_file *m, void *v) seq_puts(m, "appraise_flag=check_blacklist "); if (entry->flags & IMA_PERMIT_DIRECTIO) seq_puts(m, "permit_directio "); + if (entry->lsm->which_lsm >= 0) + seq_printf(m, pt(Opt_lsm), + lsm_slot_to_name(entry->lsm->which_lsm)); rcu_read_unlock(); seq_puts(m, "\n"); return 0; -- 2.25.4

On 2/14/2021 10:21 AM, Mimi Zohar wrote: Thank you. I will add this. You're right, that is better. I'll incorporate the change. Which would be an improvement. ima_rules_lsm seem to be more accurate. I'll fix it. Thanks for the review and recommendations.

On Mon, 2021-02-22 at 15:45 -0800, Casey Schaufler wrote: If each IMA policy rule may only contain a single LSM specific LSM_OBJ_{USER | ROLE | TYPE} and LSM_SUBJ_{USER | ROLE | TYPE}, then there is no need for rules[LSMBLOB_ENTRIES]. Leave it as "*rule". Otherwise it looks good. Mimi

Change the security_kernel_act_as interface to use a lsmblob structure in place of the single u32 secid in support of module stacking. Change its only caller, set_security_override, to do the same. Change that one's only caller, set_security_override_from_ctx, to call it with the new parameter type. The security module hook is unchanged, still taking a secid. The infrastructure passes the correct entry from the lsmblob. lsmblob_init() is used to fill the lsmblob structure, however this will be removed later in the series when security_secctx_to_secid() is updated to provide a lsmblob instead of a secid. Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; Acked-by: Stephen Smalley <sds(a)tycho.nsa.gov&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; To: David Howells <dhowells(a)redhat.com&gt; --- include/linux/cred.h | 3 ++- include/linux/security.h | 5 +++-- kernel/cred.c | 10 ++++++---- security/security.c | 14 ++++++++++++-- 4 files changed, 23 insertions(+), 9 deletions(-) diff --git a/include/linux/cred.h b/include/linux/cred.h index 18639c069263..03ae0182cba6 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -18,6 +18,7 @@ struct cred; struct inode; +struct lsmblob; /* * COW Supplementary groups list @@ -165,7 +166,7 @@ extern const struct cred *override_creds(const struct cred *); extern void revert_creds(const struct cred *); extern struct cred *prepare_kernel_cred(struct task_struct *); extern int change_create_files_as(struct cred *, struct inode *); -extern int set_security_override(struct cred *, u32); +extern int set_security_override(struct cred *, struct lsmblob *); extern int set_security_override_from_ctx(struct cred *, const char *); extern int set_create_files_as(struct cred *, struct inode *); extern int cred_fscmp(const struct cred *, const struct cred *); diff --git a/include/linux/security.h b/include/linux/security.h index 112aadf3e7f9..5d8dbfb1dabb 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -448,7 +448,7 @@ void security_cred_free(struct cred *cred); int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp); void security_transfer_creds(struct cred *new, const struct cred *old); void security_cred_getsecid(const struct cred *c, u32 *secid); -int security_kernel_act_as(struct cred *new, u32 secid); +int security_kernel_act_as(struct cred *new, struct lsmblob *blob); int security_kernel_create_files_as(struct cred *new, struct inode *inode); int security_kernel_module_request(char *kmod_name); int security_kernel_load_data(enum kernel_load_data_id id, bool contents); @@ -1066,7 +1066,8 @@ static inline void security_transfer_creds(struct cred *new, { } -static inline int security_kernel_act_as(struct cred *cred, u32 secid) +static inline int security_kernel_act_as(struct cred *cred, + struct lsmblob *blob) { return 0; } diff --git a/kernel/cred.c b/kernel/cred.c index 421b1149c651..22e0e7cbefde 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -733,14 +733,14 @@ EXPORT_SYMBOL(prepare_kernel_cred); /** * set_security_override - Set the security ID in a set of credentials * @new: The credentials to alter - * @secid: The LSM security ID to set + * @blob: The LSM security information to set * * Set the LSM security ID in a set of credentials so that the subjective * security is overridden when an alternative set of credentials is used. */ -int set_security_override(struct cred *new, u32 secid) +int set_security_override(struct cred *new, struct lsmblob *blob) { - return security_kernel_act_as(new, secid); + return security_kernel_act_as(new, blob); } EXPORT_SYMBOL(set_security_override); @@ -756,6 +756,7 @@ EXPORT_SYMBOL(set_security_override); */ int set_security_override_from_ctx(struct cred *new, const char *secctx) { + struct lsmblob blob; u32 secid; int ret; @@ -763,7 +764,8 @@ int set_security_override_from_ctx(struct cred *new, const char *secctx) if (ret < 0) return ret; - return set_security_override(new, secid); + lsmblob_init(&blob, secid); + return set_security_override(new, &blob); } EXPORT_SYMBOL(set_security_override_from_ctx); diff --git a/security/security.c b/security/security.c index 291db266fdc2..a3e162c4c0d3 100644 --- a/security/security.c +++ b/security/security.c @@ -1739,9 +1739,19 @@ void security_cred_getsecid(const struct cred *c, u32 *secid) } EXPORT_SYMBOL(security_cred_getsecid); -int security_kernel_act_as(struct cred *new, u32 secid) +int security_kernel_act_as(struct cred *new, struct lsmblob *blob) { - return call_int_hook(kernel_act_as, 0, new, secid); + struct security_hook_list *hp; + int rc; + + hlist_for_each_entry(hp, &security_hook_heads.kernel_act_as, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + rc = hp->hook.kernel_act_as(new, blob->secid[hp->lsmid->slot]); + if (rc != 0) + return rc; + } + return 0; } int security_kernel_create_files_as(struct cred *new, struct inode *inode) -- 2.25.4

Change security_secid_to_secctx() to take a lsmblob as input instead of a u32 secid. It will then call the LSM hooks using the lsmblob element allocated for that module. The callers have been updated as well. This allows for the possibility that more than one module may be called upon to translate a secid to a string, as can occur in the audit code. Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: netdev(a)vger.kernel.org Cc: linux-audit(a)redhat.com Cc: netfilter-devel(a)vger.kernel.org To: Pablo Neira Ayuso <pablo(a)netfilter.org&gt; To: Paul Moore <paul(a)paul-moore.com&gt; --- drivers/android/binder.c | 12 +++++++++- include/linux/security.h | 5 +++-- include/net/scm.h | 7 +++++- kernel/audit.c | 20 +++++++++++++++-- kernel/auditsc.c | 28 +++++++++++++++++++---- net/ipv4/ip_sockglue.c | 4 +++- net/netfilter/nf_conntrack_netlink.c | 14 ++++++++++-- net/netfilter/nf_conntrack_standalone.c | 4 +++- net/netfilter/nfnetlink_queue.c | 11 +++++++-- net/netlabel/netlabel_unlabeled.c | 30 +++++++++++++++++++++---- net/netlabel/netlabel_user.c | 6 ++--- security/security.c | 11 +++++---- 12 files changed, 123 insertions(+), 29 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index c119736ca56a..5fb8555ce166 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2698,10 +2698,20 @@ static void binder_transaction(struct binder_proc *proc, if (target_node && target_node->txn_security_ctx) { u32 secid; + struct lsmblob blob; size_t added_size; security_task_getsecid(proc->tsk, &secid); - ret = security_secid_to_secctx(secid, &secctx, &secctx_sz); + /* + * Later in this patch set security_task_getsecid() will + * provide a lsmblob instead of a secid. lsmblob_init + * is used to ensure that all the secids in the lsmblob + * get the value returned from security_task_getsecid(), + * which means that the one expected by + * security_secid_to_secctx() will be set. + */ + lsmblob_init(&blob, secid); + ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz); if (ret) { return_error = BR_FAILED_REPLY; return_error_param = ret; diff --git a/include/linux/security.h b/include/linux/security.h index af1d69b41f1c..f786d8833e7d 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -533,7 +533,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value, size_t size); int security_netlink_send(struct sock *sk, struct sk_buff *skb); int security_ismaclabel(const char *name); -int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen); +int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen); int security_secctx_to_secid(const char *secdata, u32 seclen, struct lsmblob *blob); void security_release_secctx(char *secdata, u32 seclen); @@ -1355,7 +1355,8 @@ static inline int security_ismaclabel(const char *name) return 0; } -static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) +static inline int security_secid_to_secctx(struct lsmblob *blob, + char **secdata, u32 *seclen) { return -EOPNOTSUPP; } diff --git a/include/net/scm.h b/include/net/scm.h index 1ce365f4c256..23a35ff1b3f2 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -92,12 +92,17 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg, #ifdef CONFIG_SECURITY_NETWORK static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm) { + struct lsmblob lb; char *secdata; u32 seclen; int err; if (test_bit(SOCK_PASSSEC, &sock->flags)) { - err = security_secid_to_secctx(scm->secid, &secdata, &seclen); + /* There can only be one security module using the secid, + * and the infrastructure will know which it is. + */ + lsmblob_init(&lb, scm->secid); + err = security_secid_to_secctx(&lb, &secdata, &seclen); if (!err) { put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata); diff --git a/kernel/audit.c b/kernel/audit.c index 1ffc2e059027..72f6672a445e 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1442,7 +1442,16 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) case AUDIT_SIGNAL_INFO: len = 0; if (audit_sig_sid) { - err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); + struct lsmblob blob; + + /* + * lsmblob_init sets all values in the lsmblob + * to audit_sig_sid. This is temporary until + * audit_sig_sid is converted to a lsmblob, which + * happens later in this patch set. + */ + lsmblob_init(&blob, audit_sig_sid); + err = security_secid_to_secctx(&blob, &ctx, &len); if (err) return err; } @@ -2131,12 +2140,19 @@ int audit_log_task_context(struct audit_buffer *ab) unsigned len; int error; u32 sid; + struct lsmblob blob; security_task_getsecid(current, &sid); if (!sid) return 0; - error = security_secid_to_secctx(sid, &ctx, &len); + /* + * lsmblob_init sets all values in the lsmblob to sid. + * This is temporary until security_task_getsecid is converted + * to use a lsmblob, which happens later in this patch set. + */ + lsmblob_init(&blob, sid); + error = security_secid_to_secctx(&blob, &ctx, &len); if (error) { if (error != -EINVAL) goto error_path; diff --git a/kernel/auditsc.c b/kernel/auditsc.c index a8335cbe0091..220b3a7ed326 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -671,6 +671,13 @@ static int audit_filter_rules(struct task_struct *tsk, security_task_getsecid(tsk, &sid); need_sid = 0; } + /* + * lsmblob_init sets all values in the lsmblob + * to sid. This is temporary until + * security_task_getsecid() is converted to + * provide a lsmblob, which happens later in + * this patch set. + */ lsmblob_init(&blob, sid); result = security_audit_rule_match(&blob, f->type, @@ -688,6 +695,13 @@ static int audit_filter_rules(struct task_struct *tsk, if (f->lsm_isset) { /* Find files that match */ if (name) { + /* + * lsmblob_init sets all values in the + * lsmblob to sid. This is temporary + * until name->osid is converted to a + * lsmblob, which happens later in + * this patch set. + */ lsmblob_init(&blob, name->osid); result = security_audit_rule_match( &blob, @@ -995,6 +1009,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid, char *ctx = NULL; u32 len; int rc = 0; + struct lsmblob blob; ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID); if (!ab) @@ -1004,7 +1019,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid, from_kuid(&init_user_ns, auid), from_kuid(&init_user_ns, uid), sessionid); if (sid) { - if (security_secid_to_secctx(sid, &ctx, &len)) { + lsmblob_init(&blob, sid); + if (security_secid_to_secctx(&blob, &ctx, &len)) { audit_log_format(ab, " obj=(none)"); rc = 1; } else { @@ -1247,7 +1263,10 @@ static void show_special(struct audit_context *context, int *call_panic) if (osid) { char *ctx = NULL; u32 len; - if (security_secid_to_secctx(osid, &ctx, &len)) { + struct lsmblob blob; + + lsmblob_init(&blob, osid); + if (security_secid_to_secctx(&blob, &ctx, &len)) { audit_log_format(ab, " osid=%u", osid); *call_panic = 1; } else { @@ -1400,9 +1419,10 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n, if (n->osid != 0) { char *ctx = NULL; u32 len; + struct lsmblob blob; - if (security_secid_to_secctx( - n->osid, &ctx, &len)) { + lsmblob_init(&blob, n->osid); + if (security_secid_to_secctx(&blob, &ctx, &len)) { audit_log_format(ab, " osid=%u", n->osid); if (call_panic) *call_panic = 2; diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index ec6036713e2c..2f089733ada7 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -130,6 +130,7 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb, static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb) { + struct lsmblob lb; char *secdata; u32 seclen, secid; int err; @@ -138,7 +139,8 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb) if (err) return; - err = security_secid_to_secctx(secid, &secdata, &seclen); + lsmblob_init(&lb, secid); + err = security_secid_to_secctx(&lb, &secdata, &seclen); if (err) return; diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 84caf3316946..d4902d120799 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -338,8 +338,13 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct) struct nlattr *nest_secctx; int len, ret; char *secctx; + struct lsmblob blob; - ret = security_secid_to_secctx(ct->secmark, &secctx, &len); + /* lsmblob_init() puts ct->secmark into all of the secids in blob. + * security_secid_to_secctx() will know which security module + * to use to create the secctx. */ + lsmblob_init(&blob, ct->secmark); + ret = security_secid_to_secctx(&blob, &secctx, &len); if (ret) return 0; @@ -652,8 +657,13 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct) { #ifdef CONFIG_NF_CONNTRACK_SECMARK int len, ret; + struct lsmblob blob; - ret = security_secid_to_secctx(ct->secmark, NULL, &len); + /* lsmblob_init() puts ct->secmark into all of the secids in blob. + * security_secid_to_secctx() will know which security module + * to use to create the secctx. */ + lsmblob_init(&blob, ct->secmark); + ret = security_secid_to_secctx(&blob, NULL, &len); if (ret) return 0; diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c index 46c5557c1fec..54da1a3e8cb1 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -175,8 +175,10 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct) int ret; u32 len; char *secctx; + struct lsmblob blob; - ret = security_secid_to_secctx(ct->secmark, &secctx, &len); + lsmblob_init(&blob, ct->secmark); + ret = security_secid_to_secctx(&blob, &secctx, &len); if (ret) return; diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index d1d8bca03b4f..a6dbef71fc32 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -305,13 +305,20 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata) { u32 seclen = 0; #if IS_ENABLED(CONFIG_NETWORK_SECMARK) + struct lsmblob blob; + if (!skb || !sk_fullsock(skb->sk)) return 0; read_lock_bh(&skb->sk->sk_callback_lock); - if (skb->secmark) - security_secid_to_secctx(skb->secmark, secdata, &seclen); + if (skb->secmark) { + /* lsmblob_init() puts ct->secmark into all of the secids in + * blob. security_secid_to_secctx() will know which security + * module to use to create the secctx. */ + lsmblob_init(&blob, skb->secmark); + security_secid_to_secctx(&blob, secdata, &seclen); + } read_unlock_bh(&skb->sk->sk_callback_lock); #endif diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c index df9448af23dd..0e5d03c228e7 100644 --- a/net/netlabel/netlabel_unlabeled.c +++ b/net/netlabel/netlabel_unlabeled.c @@ -376,6 +376,7 @@ int netlbl_unlhsh_add(struct net *net, struct audit_buffer *audit_buf = NULL; char *secctx = NULL; u32 secctx_len; + struct lsmblob blob; if (addr_len != sizeof(struct in_addr) && addr_len != sizeof(struct in6_addr)) @@ -438,7 +439,11 @@ int netlbl_unlhsh_add(struct net *net, unlhsh_add_return: rcu_read_unlock(); if (audit_buf != NULL) { - if (security_secid_to_secctx(secid, + /* lsmblob_init() puts secid into all of the secids in blob. + * security_secid_to_secctx() will know which security module + * to use to create the secctx. */ + lsmblob_init(&blob, secid); + if (security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " sec_obj=%s", secctx); @@ -475,6 +480,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net, struct net_device *dev; char *secctx; u32 secctx_len; + struct lsmblob blob; spin_lock(&netlbl_unlhsh_lock); list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr, @@ -494,8 +500,13 @@ static int netlbl_unlhsh_remove_addr4(struct net *net, addr->s_addr, mask->s_addr); if (dev != NULL) dev_put(dev); + /* lsmblob_init() puts entry->secid into all of the secids + * in blob. security_secid_to_secctx() will know which + * security module to use to create the secctx. */ + if (entry != NULL) + lsmblob_init(&blob, entry->secid); if (entry != NULL && - security_secid_to_secctx(entry->secid, + security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " sec_obj=%s", secctx); security_release_secctx(secctx, secctx_len); @@ -537,6 +548,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net, struct net_device *dev; char *secctx; u32 secctx_len; + struct lsmblob blob; spin_lock(&netlbl_unlhsh_lock); list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list); @@ -555,8 +567,13 @@ static int netlbl_unlhsh_remove_addr6(struct net *net, addr, mask); if (dev != NULL) dev_put(dev); + /* lsmblob_init() puts entry->secid into all of the secids + * in blob. security_secid_to_secctx() will know which + * security module to use to create the secctx. */ + if (entry != NULL) + lsmblob_init(&blob, entry->secid); if (entry != NULL && - security_secid_to_secctx(entry->secid, + security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " sec_obj=%s", secctx); security_release_secctx(secctx, secctx_len); @@ -1082,6 +1099,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd, u32 secid; char *secctx; u32 secctx_len; + struct lsmblob blob; data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid, cb_arg->seq, &netlbl_unlabel_gnl_family, @@ -1136,7 +1154,11 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd, secid = addr6->secid; } - ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len); + /* lsmblob_init() secid into all of the secids in blob. + * security_secid_to_secctx() will know which security module + * to use to create the secctx. */ + lsmblob_init(&blob, secid); + ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len); if (ret_val != 0) goto list_cb_failure; ret_val = nla_put(cb_arg->skb, diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c index 3ed4fea2a2de..893301ae0131 100644 --- a/net/netlabel/netlabel_user.c +++ b/net/netlabel/netlabel_user.c @@ -86,6 +86,7 @@ struct audit_buffer *netlbl_audit_start_common(int type, struct audit_buffer *audit_buf; char *secctx; u32 secctx_len; + struct lsmblob blob; if (audit_enabled == AUDIT_OFF) return NULL; @@ -98,10 +99,9 @@ struct audit_buffer *netlbl_audit_start_common(int type, from_kuid(&init_user_ns, audit_info->loginuid), audit_info->sessionid); + lsmblob_init(&blob, audit_info->secid); if (audit_info->secid != 0 && - security_secid_to_secctx(audit_info->secid, - &secctx, - &secctx_len) == 0) { + security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) { audit_log_format(audit_buf, " subj=%s", secctx); security_release_secctx(secctx, secctx_len); } diff --git a/security/security.c b/security/security.c index 1039f8a8ed09..271584938404 100644 --- a/security/security.c +++ b/security/security.c @@ -2108,17 +2108,16 @@ int security_ismaclabel(const char *name) } EXPORT_SYMBOL(security_ismaclabel); -int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) +int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen) { struct security_hook_list *hp; int rc; - /* - * Currently, only one LSM can implement secid_to_secctx (i.e this - * LSM hook is not "stackable"). - */ hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) { - rc = hp->hook.secid_to_secctx(secid, secdata, seclen); + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + rc = hp->hook.secid_to_secctx(blob->secid[hp->lsmid->slot], + secdata, seclen); if (rc != LSM_RET_DEFAULT(secid_to_secctx)) return rc; } -- 2.25.4

Change the security_task_getsecid() interface to fill in a lsmblob structure instead of a u32 secid in support of LSM stacking. Audit interfaces will need to collect all possible secids for possible reporting. Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; Acked-by: Stephen Smalley <sds(a)tycho.nsa.gov&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: linux-integrity(a)vger.kernel.org Cc: linux-audit(a)redhat.com Cc: netdev(a)vger.kernel.org --- drivers/android/binder.c | 12 +----- include/linux/security.h | 7 ++-- kernel/audit.c | 16 +++----- kernel/auditfilter.c | 4 +- kernel/auditsc.c | 25 ++++++------ net/netlabel/netlabel_unlabeled.c | 5 ++- net/netlabel/netlabel_user.h | 6 ++- security/integrity/ima/ima_appraise.c | 10 +++-- security/integrity/ima/ima_main.c | 56 +++++++++++++++------------ security/security.c | 12 ++++-- 10 files changed, 80 insertions(+), 73 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 5fb8555ce166..1a15e9e19e22 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2697,20 +2697,10 @@ static void binder_transaction(struct binder_proc *proc, t->priority = task_nice(current); if (target_node && target_node->txn_security_ctx) { - u32 secid; struct lsmblob blob; size_t added_size; - security_task_getsecid(proc->tsk, &secid); - /* - * Later in this patch set security_task_getsecid() will - * provide a lsmblob instead of a secid. lsmblob_init - * is used to ensure that all the secids in the lsmblob - * get the value returned from security_task_getsecid(), - * which means that the one expected by - * security_secid_to_secctx() will be set. - */ - lsmblob_init(&blob, secid); + security_task_getsecid(proc->tsk, &blob); ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz); if (ret) { return_error = BR_FAILED_REPLY; diff --git a/include/linux/security.h b/include/linux/security.h index 20a47bd3930b..9fc245c1f739 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -487,7 +487,7 @@ int security_task_fix_setgid(struct cred *new, const struct cred *old, int security_task_setpgid(struct task_struct *p, pid_t pgid); int security_task_getpgid(struct task_struct *p); int security_task_getsid(struct task_struct *p); -void security_task_getsecid(struct task_struct *p, u32 *secid); +void security_task_getsecid(struct task_struct *p, struct lsmblob *blob); int security_task_setnice(struct task_struct *p, int nice); int security_task_setioprio(struct task_struct *p, int ioprio); int security_task_getioprio(struct task_struct *p); @@ -1160,9 +1160,10 @@ static inline int security_task_getsid(struct task_struct *p) return 0; } -static inline void security_task_getsecid(struct task_struct *p, u32 *secid) +static inline void security_task_getsecid(struct task_struct *p, + struct lsmblob *blob) { - *secid = 0; + lsmblob_init(blob, 0); } static inline int security_task_setnice(struct task_struct *p, int nice) diff --git a/kernel/audit.c b/kernel/audit.c index 72f6672a445e..e70bbd6b91c4 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -2139,19 +2139,12 @@ int audit_log_task_context(struct audit_buffer *ab) char *ctx = NULL; unsigned len; int error; - u32 sid; struct lsmblob blob; - security_task_getsecid(current, &sid); - if (!sid) + security_task_getsecid(current, &blob); + if (!lsmblob_is_set(&blob)) return 0; - /* - * lsmblob_init sets all values in the lsmblob to sid. - * This is temporary until security_task_getsecid is converted - * to use a lsmblob, which happens later in this patch set. - */ - lsmblob_init(&blob, sid); error = security_secid_to_secctx(&blob, &ctx, &len); if (error) { if (error != -EINVAL) @@ -2359,6 +2352,7 @@ int audit_set_loginuid(kuid_t loginuid) int audit_signal_info(int sig, struct task_struct *t) { kuid_t uid = current_uid(), auid; + struct lsmblob blob; if (auditd_test_task(t) && (sig == SIGTERM || sig == SIGHUP || @@ -2369,7 +2363,9 @@ int audit_signal_info(int sig, struct task_struct *t) audit_sig_uid = auid; else audit_sig_uid = uid; - security_task_getsecid(current, &audit_sig_sid); + security_task_getsecid(current, &blob); + /* scaffolding until audit_sig_sid is converted */ + audit_sig_sid = blob.secid[0]; } return audit_signal_info_syscall(t); diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index e27424216159..9e73a7961665 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -1330,7 +1330,6 @@ int audit_filter(int msgtype, unsigned int listtype) for (i = 0; i < e->rule.field_count; i++) { struct audit_field *f = &e->rule.fields[i]; pid_t pid; - u32 sid; struct lsmblob blob; switch (f->type) { @@ -1361,8 +1360,7 @@ int audit_filter(int msgtype, unsigned int listtype) case AUDIT_SUBJ_SEN: case AUDIT_SUBJ_CLR: if (f->lsm_isset) { - security_task_getsecid(current, &sid); - lsmblob_init(&blob, sid); + security_task_getsecid(current, &blob); result = security_audit_rule_match( &blob, f->type, f->op, f->lsm_rules); diff --git a/kernel/auditsc.c b/kernel/auditsc.c index b3ad40787740..62e2e6de5486 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -471,7 +471,6 @@ static int audit_filter_rules(struct task_struct *tsk, { const struct cred *cred; int i, need_sid = 1; - u32 sid; struct lsmblob blob; unsigned int sessionid; @@ -668,17 +667,9 @@ static int audit_filter_rules(struct task_struct *tsk, logged upon error */ if (f->lsm_isset) { if (need_sid) { - security_task_getsecid(tsk, &sid); + security_task_getsecid(tsk, &blob); need_sid = 0; } - /* - * lsmblob_init sets all values in the lsmblob - * to sid. This is temporary until - * security_task_getsecid() is converted to - * provide a lsmblob, which happens later in - * this patch set. - */ - lsmblob_init(&blob, sid); result = security_audit_rule_match(&blob, f->type, f->op, @@ -2426,12 +2417,15 @@ int __audit_sockaddr(int len, void *a) void __audit_ptrace(struct task_struct *t) { struct audit_context *context = audit_context(); + struct lsmblob blob; context->target_pid = task_tgid_nr(t); context->target_auid = audit_get_loginuid(t); context->target_uid = task_uid(t); context->target_sessionid = audit_get_sessionid(t); - security_task_getsecid(t, &context->target_sid); + security_task_getsecid(t, &blob); + /* scaffolding - until target_sid is converted */ + context->target_sid = blob.secid[0]; memcpy(context->target_comm, t->comm, TASK_COMM_LEN); } @@ -2447,6 +2441,7 @@ int audit_signal_info_syscall(struct task_struct *t) struct audit_aux_data_pids *axp; struct audit_context *ctx = audit_context(); kuid_t t_uid = task_uid(t); + struct lsmblob blob; if (!audit_signals || audit_dummy_context()) return 0; @@ -2458,7 +2453,9 @@ int audit_signal_info_syscall(struct task_struct *t) ctx->target_auid = audit_get_loginuid(t); ctx->target_uid = t_uid; ctx->target_sessionid = audit_get_sessionid(t); - security_task_getsecid(t, &ctx->target_sid); + security_task_getsecid(t, &blob); + /* scaffolding until target_sid is converted */ + ctx->target_sid = blob.secid[0]; memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN); return 0; } @@ -2479,7 +2476,9 @@ int audit_signal_info_syscall(struct task_struct *t) axp->target_auid[axp->pid_count] = audit_get_loginuid(t); axp->target_uid[axp->pid_count] = t_uid; axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t); - security_task_getsecid(t, &axp->target_sid[axp->pid_count]); + security_task_getsecid(t, &blob); + /* scaffolding until target_sid is converted */ + axp->target_sid[axp->pid_count] = blob.secid[0]; memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN); axp->pid_count++; diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c index 0e5d03c228e7..93240432427f 100644 --- a/net/netlabel/netlabel_unlabeled.c +++ b/net/netlabel/netlabel_unlabeled.c @@ -1564,11 +1564,14 @@ int __init netlbl_unlabel_defconf(void) int ret_val; struct netlbl_dom_map *entry; struct netlbl_audit audit_info; + struct lsmblob blob; /* Only the kernel is allowed to call this function and the only time * it is called is at bootup before the audit subsystem is reporting * messages so don't worry to much about these values. */ - security_task_getsecid(current, &audit_info.secid); + security_task_getsecid(current, &blob); + /* scaffolding until audit_info.secid is converted */ + audit_info.secid = blob.secid[0]; audit_info.loginuid = GLOBAL_ROOT_UID; audit_info.sessionid = 0; diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h index 3c67afce64f1..438b5db6c714 100644 --- a/net/netlabel/netlabel_user.h +++ b/net/netlabel/netlabel_user.h @@ -34,7 +34,11 @@ static inline void netlbl_netlink_auditinfo(struct sk_buff *skb, struct netlbl_audit *audit_info) { - security_task_getsecid(current, &audit_info->secid); + struct lsmblob blob; + + security_task_getsecid(current, &blob); + /* scaffolding until secid is converted */ + audit_info->secid = blob.secid[0]; audit_info->loginuid = audit_get_loginuid(current); audit_info->sessionid = audit_get_sessionid(current); } diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 8361941ee0a1..afcf715de585 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -70,14 +70,16 @@ bool is_ima_appraise_enabled(void) */ int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func) { - u32 secid; + struct lsmblob blob; if (!ima_appraise) return 0; - security_task_getsecid(current, &secid); - return ima_match_policy(inode, current_cred(), secid, func, mask, - IMA_APPRAISE | IMA_HASH, NULL, NULL, NULL); + security_task_getsecid(current, &blob); + /* scaffolding the .secid[0] */ + return ima_match_policy(inode, current_cred(), blob.secid[0], func, + mask, IMA_APPRAISE | IMA_HASH, NULL, NULL, + NULL); } static int ima_fix_xattr(struct dentry *dentry, diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index f87cb29329e9..175a79076569 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -388,12 +388,13 @@ static int process_measurement(struct file *file, const struct cred *cred, */ int ima_file_mmap(struct file *file, unsigned long prot) { - u32 secid; + struct lsmblob blob; if (file && (prot & PROT_EXEC)) { - security_task_getsecid(current, &secid); - return process_measurement(file, current_cred(), secid, NULL, - 0, MAY_EXEC, MMAP_CHECK); + security_task_getsecid(current, &blob); + /* scaffolding - until process_measurement changes */ + return process_measurement(file, current_cred(), blob.secid[0], + NULL, 0, MAY_EXEC, MMAP_CHECK); } return 0; @@ -419,9 +420,9 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot) char *pathbuf = NULL; const char *pathname = NULL; struct inode *inode; + struct lsmblob blob; int result = 0; int action; - u32 secid; int pcr; /* Is mprotect making an mmap'ed file executable? */ @@ -429,9 +430,10 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot) !(prot & PROT_EXEC) || (vma->vm_flags & VM_EXEC)) return 0; - security_task_getsecid(current, &secid); + security_task_getsecid(current, &blob); inode = file_inode(vma->vm_file); - action = ima_get_action(inode, current_cred(), secid, MAY_EXEC, + /* scaffolding */ + action = ima_get_action(NULL, current_cred(), blob.secid[0], 0, MMAP_CHECK, &pcr, &template, 0); /* Is the mmap'ed file in policy? */ @@ -468,10 +470,12 @@ int ima_bprm_check(struct linux_binprm *bprm) { int ret; u32 secid; + struct lsmblob blob; - security_task_getsecid(current, &secid); - ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0, - MAY_EXEC, BPRM_CHECK); + security_task_getsecid(current, &blob); + /* scaffolding until process_measurement changes */ + ret = process_measurement(bprm->file, current_cred(), blob.secid[0], + NULL, 0, MAY_EXEC, BPRM_CHECK); if (ret) return ret; @@ -492,10 +496,11 @@ int ima_bprm_check(struct linux_binprm *bprm) */ int ima_file_check(struct file *file, int mask) { - u32 secid; + struct lsmblob blob; - security_task_getsecid(current, &secid); - return process_measurement(file, current_cred(), secid, NULL, 0, + security_task_getsecid(current, &blob); + /* scaffolding until process_measurement changes */ + return process_measurement(file, current_cred(), blob.secid[0], NULL, 0, mask & (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND), FILE_CHECK); } @@ -659,7 +664,7 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id, bool contents) { enum ima_hooks func; - u32 secid; + struct lsmblob blob; /* * Do devices using pre-allocated memory run the risk of the @@ -679,8 +684,9 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id, /* Read entire file for all partial reads. */ func = read_idmap[read_id] ?: FILE_CHECK; - security_task_getsecid(current, &secid); - return process_measurement(file, current_cred(), secid, NULL, + security_task_getsecid(current, &blob); + /* scaffolding - until process_measurement changes */ + return process_measurement(file, current_cred(), blob.secid[0], NULL, 0, MAY_READ, func); } @@ -709,7 +715,7 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size, enum kernel_read_file_id read_id) { enum ima_hooks func; - u32 secid; + struct lsmblob blob; /* permit signed certs */ if (!file && read_id == READING_X509_CERTIFICATE) @@ -722,9 +728,10 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size, } func = read_idmap[read_id] ?: FILE_CHECK; - security_task_getsecid(current, &secid); - return process_measurement(file, current_cred(), secid, buf, size, - MAY_READ, func); + security_task_getsecid(current, &blob); + /* scaffolding until process_measurement changes */ + return process_measurement(file, current_cred(), blob.secid[0], buf, + size, MAY_READ, func); } /** @@ -839,7 +846,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size, } hash = {}; int violation = 0; int action = 0; - u32 secid; + struct lsmblob blob; if (!ima_policy_flag) return; @@ -859,9 +866,10 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size, * buffer measurements. */ if (func) { - security_task_getsecid(current, &secid); - action = ima_get_action(inode, current_cred(), secid, 0, func, - &pcr, &template, keyring); + security_task_getsecid(current, &blob); + /* scaffolding */ + action = ima_get_action(inode, current_cred(), blob.secid[0], + 0, func, &pcr, &template, keyring); if (!(action & IMA_MEASURE)) return; } diff --git a/security/security.c b/security/security.c index 197f69780783..3f0a3aedad19 100644 --- a/security/security.c +++ b/security/security.c @@ -1845,10 +1845,16 @@ int security_task_getsid(struct task_struct *p) return call_int_hook(task_getsid, 0, p); } -void security_task_getsecid(struct task_struct *p, u32 *secid) +void security_task_getsecid(struct task_struct *p, struct lsmblob *blob) { - *secid = 0; - call_void_hook(task_getsecid, p, secid); + struct security_hook_list *hp; + + lsmblob_init(blob, 0); + hlist_for_each_entry(hp, &security_hook_heads.task_getsecid, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + hp->hook.task_getsecid(p, &blob->secid[hp->lsmid->slot]); + } } EXPORT_SYMBOL(security_task_getsecid); -- 2.25.4

Change the security_cred_getsecid() interface to fill in a lsmblob instead of a u32 secid. The associated data elements in the audit sub-system are changed from a secid to a lsmblob to accommodate multiple possible LSM audit users. Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; Acked-by: Stephen Smalley <sds(a)tycho.nsa.gov&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: linux-integrity(a)vger.kernel.org Cc: linux-audit(a)redhat.com --- include/linux/security.h | 2 +- kernel/audit.c | 25 +++++++---------------- kernel/audit.h | 3 ++- kernel/auditsc.c | 33 +++++++++++-------------------- security/integrity/ima/ima_main.c | 8 ++++---- security/security.c | 12 ++++++++--- 6 files changed, 35 insertions(+), 48 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index e8d73b0220e4..e4a4816f1b94 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -468,7 +468,7 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp); void security_cred_free(struct cred *cred); int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp); void security_transfer_creds(struct cred *new, const struct cred *old); -void security_cred_getsecid(const struct cred *c, u32 *secid); +void security_cred_getsecid(const struct cred *c, struct lsmblob *blob); int security_kernel_act_as(struct cred *new, struct lsmblob *blob); int security_kernel_create_files_as(struct cred *new, struct inode *inode); int security_kernel_module_request(char *kmod_name); diff --git a/kernel/audit.c b/kernel/audit.c index e70bbd6b91c4..f6af7b27a6fa 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -125,7 +125,7 @@ static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME; /* The identity of the user shutting down the audit system. */ static kuid_t audit_sig_uid = INVALID_UID; static pid_t audit_sig_pid = -1; -static u32 audit_sig_sid; +struct lsmblob audit_sig_lsm; /* Records can be lost in several ways: 0) [suppressed in audit_alloc] @@ -1441,29 +1441,21 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) } case AUDIT_SIGNAL_INFO: len = 0; - if (audit_sig_sid) { - struct lsmblob blob; - - /* - * lsmblob_init sets all values in the lsmblob - * to audit_sig_sid. This is temporary until - * audit_sig_sid is converted to a lsmblob, which - * happens later in this patch set. - */ - lsmblob_init(&blob, audit_sig_sid); - err = security_secid_to_secctx(&blob, &ctx, &len); + if (lsmblob_is_set(&audit_sig_lsm)) { + err = security_secid_to_secctx(&audit_sig_lsm, &ctx, + &len); if (err) return err; } sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); if (!sig_data) { - if (audit_sig_sid) + if (lsmblob_is_set(&audit_sig_lsm)) security_release_secctx(ctx, len); return -ENOMEM; } sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); sig_data->pid = audit_sig_pid; - if (audit_sig_sid) { + if (lsmblob_is_set(&audit_sig_lsm)) { memcpy(sig_data->ctx, ctx, len); security_release_secctx(ctx, len); } @@ -2352,7 +2344,6 @@ int audit_set_loginuid(kuid_t loginuid) int audit_signal_info(int sig, struct task_struct *t) { kuid_t uid = current_uid(), auid; - struct lsmblob blob; if (auditd_test_task(t) && (sig == SIGTERM || sig == SIGHUP || @@ -2363,9 +2354,7 @@ int audit_signal_info(int sig, struct task_struct *t) audit_sig_uid = auid; else audit_sig_uid = uid; - security_task_getsecid(current, &blob); - /* scaffolding until audit_sig_sid is converted */ - audit_sig_sid = blob.secid[0]; + security_task_getsecid(current, &audit_sig_lsm); } return audit_signal_info_syscall(t); diff --git a/kernel/audit.h b/kernel/audit.h index 3b9c0945225a..ce41886807bb 100644 --- a/kernel/audit.h +++ b/kernel/audit.h @@ -9,6 +9,7 @@ #include <linux/fs.h> #include <linux/audit.h> #include <linux/skbuff.h> +#include <linux/security.h> #include <uapi/linux/mqueue.h> #include <linux/tty.h> @@ -134,7 +135,7 @@ struct audit_context { kuid_t target_auid; kuid_t target_uid; unsigned int target_sessionid; - u32 target_sid; + struct lsmblob target_lsm; char target_comm[TASK_COMM_LEN]; struct audit_tree_refs *trees, *first_trees; diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 7883b8ac8ea4..c766502b58f2 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -111,7 +111,7 @@ struct audit_aux_data_pids { kuid_t target_auid[AUDIT_AUX_PIDS]; kuid_t target_uid[AUDIT_AUX_PIDS]; unsigned int target_sessionid[AUDIT_AUX_PIDS]; - u32 target_sid[AUDIT_AUX_PIDS]; + struct lsmblob target_lsm[AUDIT_AUX_PIDS]; char target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN]; int pid_count; }; @@ -993,14 +993,14 @@ static inline void audit_free_context(struct audit_context *context) } static int audit_log_pid_context(struct audit_context *context, pid_t pid, - kuid_t auid, kuid_t uid, unsigned int sessionid, - u32 sid, char *comm) + kuid_t auid, kuid_t uid, + unsigned int sessionid, + struct lsmblob *blob, char *comm) { struct audit_buffer *ab; char *ctx = NULL; u32 len; int rc = 0; - struct lsmblob blob; ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID); if (!ab) @@ -1009,9 +1009,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid, audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid, from_kuid(&init_user_ns, auid), from_kuid(&init_user_ns, uid), sessionid); - if (sid) { - lsmblob_init(&blob, sid); - if (security_secid_to_secctx(&blob, &ctx, &len)) { + if (lsmblob_is_set(blob)) { + if (security_secid_to_secctx(blob, &ctx, &len)) { audit_log_format(ab, " obj=(none)"); rc = 1; } else { @@ -1582,7 +1581,7 @@ static void audit_log_exit(void) axs->target_auid[i], axs->target_uid[i], axs->target_sessionid[i], - axs->target_sid[i], + &axs->target_lsm[i], axs->target_comm[i])) call_panic = 1; } @@ -1591,7 +1590,7 @@ static void audit_log_exit(void) audit_log_pid_context(context, context->target_pid, context->target_auid, context->target_uid, context->target_sessionid, - context->target_sid, context->target_comm)) + &context->target_lsm, context->target_comm)) call_panic = 1; if (context->pwd.dentry && context->pwd.mnt) { @@ -1769,7 +1768,7 @@ void __audit_syscall_exit(int success, long return_code) context->aux = NULL; context->aux_pids = NULL; context->target_pid = 0; - context->target_sid = 0; + lsmblob_init(&context->target_lsm, 0); context->sockaddr_len = 0; context->type = 0; context->fds[0] = -1; @@ -2421,15 +2420,12 @@ int __audit_sockaddr(int len, void *a) void __audit_ptrace(struct task_struct *t) { struct audit_context *context = audit_context(); - struct lsmblob blob; context->target_pid = task_tgid_nr(t); context->target_auid = audit_get_loginuid(t); context->target_uid = task_uid(t); context->target_sessionid = audit_get_sessionid(t); - security_task_getsecid(t, &blob); - /* scaffolding - until target_sid is converted */ - context->target_sid = blob.secid[0]; + security_task_getsecid(t, &context->target_lsm); memcpy(context->target_comm, t->comm, TASK_COMM_LEN); } @@ -2445,7 +2441,6 @@ int audit_signal_info_syscall(struct task_struct *t) struct audit_aux_data_pids *axp; struct audit_context *ctx = audit_context(); kuid_t t_uid = task_uid(t); - struct lsmblob blob; if (!audit_signals || audit_dummy_context()) return 0; @@ -2457,9 +2452,7 @@ int audit_signal_info_syscall(struct task_struct *t) ctx->target_auid = audit_get_loginuid(t); ctx->target_uid = t_uid; ctx->target_sessionid = audit_get_sessionid(t); - security_task_getsecid(t, &blob); - /* scaffolding until target_sid is converted */ - ctx->target_sid = blob.secid[0]; + security_task_getsecid(t, &ctx->target_lsm); memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN); return 0; } @@ -2480,9 +2473,7 @@ int audit_signal_info_syscall(struct task_struct *t) axp->target_auid[axp->pid_count] = audit_get_loginuid(t); axp->target_uid[axp->pid_count] = t_uid; axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t); - security_task_getsecid(t, &blob); - /* scaffolding until target_sid is converted */ - axp->target_sid[axp->pid_count] = blob.secid[0]; + security_task_getsecid(t, &axp->target_lsm[axp->pid_count]); memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN); axp->pid_count++; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 175a79076569..e4ed01b1919a 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -469,7 +469,6 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot) int ima_bprm_check(struct linux_binprm *bprm) { int ret; - u32 secid; struct lsmblob blob; security_task_getsecid(current, &blob); @@ -479,9 +478,10 @@ int ima_bprm_check(struct linux_binprm *bprm) if (ret) return ret; - security_cred_getsecid(bprm->cred, &secid); - return process_measurement(bprm->file, bprm->cred, secid, NULL, 0, - MAY_EXEC, CREDS_CHECK); + security_cred_getsecid(bprm->cred, &blob); + /* scaffolding until process_measurement changes */ + return process_measurement(bprm->file, bprm->cred, blob.secid[0], + NULL, 0, MAY_EXEC, CREDS_CHECK); } /** diff --git a/security/security.c b/security/security.c index 9241245a9d4b..45824239cb2f 100644 --- a/security/security.c +++ b/security/security.c @@ -1739,10 +1739,16 @@ void security_transfer_creds(struct cred *new, const struct cred *old) call_void_hook(cred_transfer, new, old); } -void security_cred_getsecid(const struct cred *c, u32 *secid) +void security_cred_getsecid(const struct cred *c, struct lsmblob *blob) { - *secid = 0; - call_void_hook(cred_getsecid, c, secid); + struct security_hook_list *hp; + + lsmblob_init(blob, 0); + hlist_for_each_entry(hp, &security_hook_heads.cred_getsecid, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + hp->hook.cred_getsecid(c, &blob->secid[hp->lsmid->slot]); + } } EXPORT_SYMBOL(security_cred_getsecid); -- 2.25.4

Create a new entry "interface_lsm" in the procfs attr directory for controlling which LSM security information is displayed for a process. A process can only read or write its own display value. The name of an active LSM that supplies hooks for human readable data may be written to "interface_lsm" to set the value. The name of the LSM currently in use can be read from "interface_lsm". At this point there can only be one LSM capable of display active. A helper function lsm_task_ilsm() is provided to get the interface lsm slot for a task_struct. Setting the "interface_lsm" requires that all security modules using setprocattr hooks allow the action. Each security module is responsible for defining its policy. AppArmor hook provided by John Johansen <john.johansen(a)canonical.com&gt; SELinux hook provided by Stephen Smalley <stephen.smalley.work(a)gmail.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: Kees Cook <keescook(a)chromium.org&gt; Cc: Stephen Smalley <stephen.smalley.work(a)gmail.com&gt; Cc: Paul Moore <paul(a)paul-moore.com&gt; Cc: John Johansen <john.johansen(a)canonical.com&gt; Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org&gt; Cc: linux-api(a)vger.kernel.org Cc: linux-doc(a)vger.kernel.org --- .../ABI/testing/procfs-attr-lsm_display | 22 +++ Documentation/security/lsm.rst | 14 ++ fs/proc/base.c | 1 + include/linux/lsm_hooks.h | 17 ++ security/apparmor/include/apparmor.h | 3 +- security/apparmor/lsm.c | 32 ++++ security/security.c | 166 ++++++++++++++++-- security/selinux/hooks.c | 11 ++ security/selinux/include/classmap.h | 2 +- security/smack/smack_lsm.c | 7 + 10 files changed, 256 insertions(+), 19 deletions(-) create mode 100644 Documentation/ABI/testing/procfs-attr-lsm_display diff --git a/Documentation/ABI/testing/procfs-attr-lsm_display b/Documentation/ABI/testing/procfs-attr-lsm_display new file mode 100644 index 000000000000..0f60005c235c --- /dev/null +++ b/Documentation/ABI/testing/procfs-attr-lsm_display @@ -0,0 +1,22 @@ +What: /proc/*/attr/lsm_display +Contact: linux-security-module(a)vger.kernel.org, +Description: The name of the Linux security module (LSM) that will + provide information in the /proc/*/attr/current, + /proc/*/attr/prev and /proc/*/attr/exec interfaces. + The details of permissions required to read from + this interface are dependent on the LSMs active on the + system. + A process cannot write to this interface unless it + refers to itself. + The other details of permissions required to write to + this interface are dependent on the LSMs active on the + system. + The format of the data used by this interface is a + text string identifying the name of an LSM. The values + accepted are: + selinux - the SELinux LSM + smack - the Smack LSM + apparmor - The AppArmor LSM + By convention the LSM names are lower case and do not + contain special characters. +Users: LSM user-space diff --git a/Documentation/security/lsm.rst b/Documentation/security/lsm.rst index 6a2a2e973080..b77b4a540391 100644 --- a/Documentation/security/lsm.rst +++ b/Documentation/security/lsm.rst @@ -129,3 +129,17 @@ to identify it as the first security module to be registered. The capabilities security module does not use the general security blobs, unlike other modules. The reasons are historical and are based on overhead, complexity and performance concerns. + +LSM External Interfaces +======================= + +The LSM infrastructure does not generally provide external interfaces. +The individual security modules provide what external interfaces they +require. + +The file ``/sys/kernel/security/lsm`` provides a comma +separated list of the active security modules. + +The file ``/proc/pid/attr/interface_lsm`` contains the name of the security +module for which the ``/proc/pid/attr/current`` interface will +apply. This interface can be written to. diff --git a/fs/proc/base.c b/fs/proc/base.c index b3422cda2a91..158771f87e94 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2808,6 +2808,7 @@ static const struct pid_entry attr_dir_stuff[] = { ATTR(NULL, "fscreate", 0666), ATTR(NULL, "keycreate", 0666), ATTR(NULL, "sockcreate", 0666), + ATTR(NULL, "interface_lsm", 0666), #ifdef CONFIG_SECURITY_SMACK DIR("smack", 0555, proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops), diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index fb32b502080b..28a036374834 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1660,4 +1660,21 @@ static inline void security_delete_hooks(struct security_hook_list *hooks, extern int lsm_inode_alloc(struct inode *inode); +/** + * lsm_task_ilsm - the "interface_lsm" for this task + * @task: The task to report on + * + * Returns the task's interface LSM slot. + */ +static inline int lsm_task_ilsm(struct task_struct *task) +{ +#ifdef CONFIG_SECURITY + int *ilsm = task->security; + + if (ilsm) + return *ilsm; +#endif + return LSMBLOB_INVALID; +} + #endif /* ! __LINUX_LSM_HOOKS_H */ diff --git a/security/apparmor/include/apparmor.h b/security/apparmor/include/apparmor.h index 1fbabdb565a8..b1622fcb4394 100644 --- a/security/apparmor/include/apparmor.h +++ b/security/apparmor/include/apparmor.h @@ -28,8 +28,9 @@ #define AA_CLASS_SIGNAL 10 #define AA_CLASS_NET 14 #define AA_CLASS_LABEL 16 +#define AA_CLASS_DISPLAY_LSM 17 -#define AA_CLASS_LAST AA_CLASS_LABEL +#define AA_CLASS_LAST AA_CLASS_DISPLAY_LSM /* Control parameters settable through module/boot flags */ extern enum audit_mode aa_g_audit; diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 1dfb8648136e..bfcb78149e9c 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -612,6 +612,25 @@ static int apparmor_getprocattr(struct task_struct *task, char *name, return error; } + +static int profile_interface_lsm(struct aa_profile *profile, + struct common_audit_data *sa) +{ + struct aa_perms perms = { }; + unsigned int state; + + state = PROFILE_MEDIATES(profile, AA_CLASS_DISPLAY_LSM); + if (state) { + aa_compute_perms(profile->policy.dfa, state, &perms); + aa_apply_modes_to_perms(profile, &perms); + aad(sa)->label = &profile->label; + + return aa_check_perms(profile, &perms, AA_MAY_WRITE, sa, NULL); + } + + return 0; +} + static int apparmor_setprocattr(const char *name, void *value, size_t size) { @@ -623,6 +642,19 @@ static int apparmor_setprocattr(const char *name, void *value, if (size == 0) return -EINVAL; + /* LSM infrastructure does actual setting of interface_lsm if allowed */ + if (!strcmp(name, "interface_lsm")) { + struct aa_profile *profile; + struct aa_label *label; + + aad(&sa)->info = "set interface lsm"; + label = begin_current_label_crit_section(); + error = fn_for_each_confined(label, profile, + profile_interface_lsm(profile, &sa)); + end_current_label_crit_section(label); + return error; + } + /* AppArmor requires that the buffer must be null terminated atm */ if (args[size - 1] != '\0') { /* null terminate */ diff --git a/security/security.c b/security/security.c index 45824239cb2f..517623ba81dc 100644 --- a/security/security.c +++ b/security/security.c @@ -77,7 +77,16 @@ static struct kmem_cache *lsm_file_cache; static struct kmem_cache *lsm_inode_cache; char *lsm_names; -static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init; + +/* + * The task blob includes the "interface_lsm" slot used for + * chosing which module presents contexts. + * Using a long to avoid potential alignment issues with + * module assigned task blobs. + */ +static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init = { + .lbs_task = sizeof(long), +}; /* Boot-time LSM user choice */ static __initdata const char *chosen_lsm_order; @@ -667,6 +676,8 @@ int lsm_inode_alloc(struct inode *inode) */ static int lsm_task_alloc(struct task_struct *task) { + int *ilsm; + if (blob_sizes.lbs_task == 0) { task->security = NULL; return 0; @@ -675,6 +686,15 @@ static int lsm_task_alloc(struct task_struct *task) task->security = kzalloc(blob_sizes.lbs_task, GFP_KERNEL); if (task->security == NULL) return -ENOMEM; + + /* + * The start of the task blob contains the "interface" LSM slot number. + * Start with it set to the invalid slot number, indicating that the + * default first registered LSM be displayed. + */ + ilsm = task->security; + *ilsm = LSMBLOB_INVALID; + return 0; } @@ -1675,14 +1695,26 @@ int security_file_open(struct file *file) int security_task_alloc(struct task_struct *task, unsigned long clone_flags) { + int *oilsm = current->security; + int *nilsm; int rc = lsm_task_alloc(task); - if (rc) + if (unlikely(rc)) return rc; + rc = call_int_hook(task_alloc, 0, task, clone_flags); - if (unlikely(rc)) + if (unlikely(rc)) { security_task_free(task); - return rc; + return rc; + } + + if (oilsm) { + nilsm = task->security; + if (nilsm) + *nilsm = *oilsm; + } + + return 0; } void security_task_free(struct task_struct *task) @@ -2100,23 +2132,110 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name, char **value) { struct security_hook_list *hp; + int ilsm = lsm_task_ilsm(current); + int slot = 0; + + if (!strcmp(name, "interface_lsm")) { + /* + * lsm_slot will be 0 if there are no displaying modules. + */ + if (lsm_slot == 0) + return -EINVAL; + + /* + * Only allow getting the current process' interface_lsm. + * There are too few reasons to get another process' + * interface_lsm and too many LSM policy issues. + */ + if (current != p) + return -EINVAL; + + ilsm = lsm_task_ilsm(p); + if (ilsm != LSMBLOB_INVALID) + slot = ilsm; + *value = kstrdup(lsm_slotlist[slot]->lsm, GFP_KERNEL); + if (*value) + return strlen(*value); + return -ENOMEM; + } hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) { if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm)) continue; + if (lsm == NULL && ilsm != LSMBLOB_INVALID && + ilsm != hp->lsmid->slot) + continue; return hp->hook.getprocattr(p, name, value); } return LSM_RET_DEFAULT(getprocattr); } +/** + * security_setprocattr - Set process attributes via /proc + * @lsm: name of module involved, or NULL + * @name: name of the attribute + * @value: value to set the attribute to + * @size: size of the value + * + * Set the process attribute for the specified security module + * to the specified value. Note that this can only be used to set + * the process attributes for the current, or "self" process. + * The /proc code has already done this check. + * + * Returns 0 on success, an appropriate code otherwise. + */ int security_setprocattr(const char *lsm, const char *name, void *value, size_t size) { struct security_hook_list *hp; + char *termed; + char *copy; + int *ilsm = current->security; + int rc = -EINVAL; + int slot = 0; + + if (!strcmp(name, "interface_lsm")) { + /* + * Change the "interface_lsm" value only if all the security + * modules that support setting a procattr allow it. + * It is assumed that all such security modules will be + * cooperative. + */ + if (size == 0) + return -EINVAL; + + hlist_for_each_entry(hp, &security_hook_heads.setprocattr, + list) { + rc = hp->hook.setprocattr(name, value, size); + if (rc < 0) + return rc; + } + + rc = -EINVAL; + + copy = kmemdup_nul(value, size, GFP_KERNEL); + if (copy == NULL) + return -ENOMEM; + + termed = strsep(&copy, " \n"); + + for (slot = 0; slot < lsm_slot; slot++) + if (!strcmp(termed, lsm_slotlist[slot]->lsm)) { + *ilsm = lsm_slotlist[slot]->slot; + rc = size; + break; + } + + kfree(termed); + return rc; + } hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) { if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm)) continue; + if (lsm == NULL && *ilsm != LSMBLOB_INVALID && + *ilsm != hp->lsmid->slot) + continue; return hp->hook.setprocattr(name, value, size); } return LSM_RET_DEFAULT(setprocattr); @@ -2136,15 +2255,15 @@ EXPORT_SYMBOL(security_ismaclabel); int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen) { struct security_hook_list *hp; - int rc; + int ilsm = lsm_task_ilsm(current); hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) { if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) continue; - rc = hp->hook.secid_to_secctx(blob->secid[hp->lsmid->slot], - secdata, seclen); - if (rc != LSM_RET_DEFAULT(secid_to_secctx)) - return rc; + if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) + return hp->hook.secid_to_secctx( + blob->secid[hp->lsmid->slot], + secdata, seclen); } return LSM_RET_DEFAULT(secid_to_secctx); @@ -2155,16 +2274,15 @@ int security_secctx_to_secid(const char *secdata, u32 seclen, struct lsmblob *blob) { struct security_hook_list *hp; - int rc; + int ilsm = lsm_task_ilsm(current); lsmblob_init(blob, 0); hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) { if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) continue; - rc = hp->hook.secctx_to_secid(secdata, seclen, - &blob->secid[hp->lsmid->slot]); - if (rc != 0) - return rc; + if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) + return hp->hook.secctx_to_secid(secdata, seclen, + &blob->secid[hp->lsmid->slot]); } return 0; } @@ -2172,7 +2290,14 @@ EXPORT_SYMBOL(security_secctx_to_secid); void security_release_secctx(char *secdata, u32 seclen) { - call_void_hook(release_secctx, secdata, seclen); + struct security_hook_list *hp; + int ilsm = lsm_task_ilsm(current); + + hlist_for_each_entry(hp, &security_hook_heads.release_secctx, list) + if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) { + hp->hook.release_secctx(secdata, seclen); + return; + } } EXPORT_SYMBOL(security_release_secctx); @@ -2313,8 +2438,15 @@ EXPORT_SYMBOL(security_sock_rcv_skb); int security_socket_getpeersec_stream(struct socket *sock, char __user *optval, int __user *optlen, unsigned len) { - return call_int_hook(socket_getpeersec_stream, -ENOPROTOOPT, sock, - optval, optlen, len); + int ilsm = lsm_task_ilsm(current); + struct security_hook_list *hp; + + hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_stream, + list) + if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) + return hp->hook.socket_getpeersec_stream(sock, optval, + optlen, len); + return -ENOPROTOOPT; } int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 49f721511b55..7bc9a043a30a 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -6342,6 +6342,17 @@ static int selinux_setprocattr(const char *name, void *value, size_t size) /* * Basic control over ability to set these attributes at all. */ + + /* + * For setting interface_lsm, we only perform a permission check; + * the actual update to the interface_lsm value is handled by the + * LSM framework. + */ + if (!strcmp(name, "interface_lsm")) + return avc_has_perm(&selinux_state, + mysid, mysid, SECCLASS_PROCESS2, + PROCESS2__SETDISPLAY, NULL); + if (!strcmp(name, "exec")) error = avc_has_perm(&selinux_state, mysid, mysid, SECCLASS_PROCESS, diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h index 40cebde62856..1858aa47b32a 100644 --- a/security/selinux/include/classmap.h +++ b/security/selinux/include/classmap.h @@ -53,7 +53,7 @@ struct security_class_mapping secclass_map[] = { "execmem", "execstack", "execheap", "setkeycreate", "setsockcreate", "getrlimit", NULL } }, { "process2", - { "nnp_transition", "nosuid_transition", NULL } }, + { "nnp_transition", "nosuid_transition", "setdisplay", NULL } }, { "system", { "ipc_info", "syslog_read", "syslog_mod", "syslog_console", "module_request", "module_load", NULL } }, diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 010f97c703aa..ef04029dcdf1 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -3509,6 +3509,13 @@ static int smack_setprocattr(const char *name, void *value, size_t size) struct smack_known_list_elem *sklep; int rc; + /* + * Allow the /proc/.../attr/current and SO_PEERSEC "interface_lsm" + * to be reset at will. + */ + if (strcmp(name, "interface_lsm") == 0) + return 0; + if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel)) return -EPERM; -- 2.25.4

Replace the (secctx,seclen) pointer pair with a single lsmcontext pointer to allow return of the LSM identifier along with the context and context length. This allows security_release_secctx() to know how to release the context. Callers have been modified to use or save the returned data from the new structure. Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Acked-by: Stephen Smalley <sds(a)tycho.nsa.gov&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: netdev(a)vger.kernel.org Cc: linux-audit(a)redhat.com Cc: netfilter-devel(a)vger.kernel.org --- drivers/android/binder.c | 26 +++++++--------- include/linux/security.h | 4 +-- include/net/scm.h | 9 ++---- kernel/audit.c | 39 +++++++++++------------- kernel/auditsc.c | 31 +++++++------------ net/ipv4/ip_sockglue.c | 8 ++--- net/netfilter/nf_conntrack_netlink.c | 18 +++++------ net/netfilter/nf_conntrack_standalone.c | 7 ++--- net/netfilter/nfnetlink_queue.c | 5 +++- net/netlabel/netlabel_unlabeled.c | 40 ++++++++----------------- net/netlabel/netlabel_user.c | 7 ++--- security/security.c | 10 +++++-- 12 files changed, 81 insertions(+), 123 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index f74a72867ec9..4c810ea52ab7 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2446,9 +2446,7 @@ static void binder_transaction(struct binder_proc *proc, binder_size_t last_fixup_min_off = 0; struct binder_context *context = proc->context; int t_debug_id = atomic_inc_return(&binder_last_id); - char *secctx = NULL; - u32 secctx_sz = 0; - struct lsmcontext scaff; /* scaffolding */ + struct lsmcontext lsmctx = { }; e = binder_transaction_log_add(&binder_transaction_log); e->debug_id = t_debug_id; @@ -2702,14 +2700,14 @@ static void binder_transaction(struct binder_proc *proc, size_t added_size; security_task_getsecid(proc->tsk, &blob); - ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz); + ret = security_secid_to_secctx(&blob, &lsmctx); if (ret) { return_error = BR_FAILED_REPLY; return_error_param = ret; return_error_line = __LINE__; goto err_get_secctx_failed; } - added_size = ALIGN(secctx_sz, sizeof(u64)); + added_size = ALIGN(lsmctx.len, sizeof(u64)); extra_buffers_size += added_size; if (extra_buffers_size < added_size) { /* integer overflow of extra_buffers_size */ @@ -2736,24 +2734,22 @@ static void binder_transaction(struct binder_proc *proc, t->buffer = NULL; goto err_binder_alloc_buf_failed; } - if (secctx) { + if (lsmctx.context) { int err; size_t buf_offset = ALIGN(tr->data_size, sizeof(void *)) + ALIGN(tr->offsets_size, sizeof(void *)) + ALIGN(extra_buffers_size, sizeof(void *)) - - ALIGN(secctx_sz, sizeof(u64)); + ALIGN(lsmctx.len, sizeof(u64)); t->security_ctx = (uintptr_t)t->buffer->user_data + buf_offset; err = binder_alloc_copy_to_buffer(&target_proc->alloc, t->buffer, buf_offset, - secctx, secctx_sz); + lsmctx.context, lsmctx.len); if (err) { t->security_ctx = 0; WARN_ON(1); } - lsmcontext_init(&scaff, secctx, secctx_sz, 0); - security_release_secctx(&scaff); - secctx = NULL; + security_release_secctx(&lsmctx); } t->buffer->debug_id = t->debug_id; t->buffer->transaction = t; @@ -2810,7 +2806,7 @@ static void binder_transaction(struct binder_proc *proc, off_end_offset = off_start_offset + tr->offsets_size; sg_buf_offset = ALIGN(off_end_offset, sizeof(void *)); sg_buf_end_offset = sg_buf_offset + extra_buffers_size - - ALIGN(secctx_sz, sizeof(u64)); + ALIGN(lsmctx.len, sizeof(u64)); off_min = 0; for (buffer_offset = off_start_offset; buffer_offset < off_end_offset; buffer_offset += sizeof(binder_size_t)) { @@ -3086,10 +3082,8 @@ static void binder_transaction(struct binder_proc *proc, binder_alloc_free_buf(&target_proc->alloc, t->buffer); err_binder_alloc_buf_failed: err_bad_extra_size: - if (secctx) { - lsmcontext_init(&scaff, secctx, secctx_sz, 0); - security_release_secctx(&scaff); - } + if (lsmctx.context) + security_release_secctx(&lsmctx); err_get_secctx_failed: kfree(tcomplete); binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE); diff --git a/include/linux/security.h b/include/linux/security.h index cfa19eb9533b..ead44674cea2 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -564,7 +564,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value, size_t size); int security_netlink_send(struct sock *sk, struct sk_buff *skb); int security_ismaclabel(const char *name); -int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen); +int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp); int security_secctx_to_secid(const char *secdata, u32 seclen, struct lsmblob *blob); void security_release_secctx(struct lsmcontext *cp); @@ -1390,7 +1390,7 @@ static inline int security_ismaclabel(const char *name) } static inline int security_secid_to_secctx(struct lsmblob *blob, - char **secdata, u32 *seclen) + struct lsmcontext *cp) { return -EOPNOTSUPP; } diff --git a/include/net/scm.h b/include/net/scm.h index f273c4d777ec..b77a52f93389 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -94,8 +94,6 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc { struct lsmcontext context; struct lsmblob lb; - char *secdata; - u32 seclen; int err; if (test_bit(SOCK_PASSSEC, &sock->flags)) { @@ -103,12 +101,11 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc * and the infrastructure will know which it is. */ lsmblob_init(&lb, scm->secid); - err = security_secid_to_secctx(&lb, &secdata, &seclen); + err = security_secid_to_secctx(&lb, &context); if (!err) { - put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata); - /*scaffolding*/ - lsmcontext_init(&context, secdata, seclen, 0); + put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, context.len, + context.context); security_release_secctx(&context); } } diff --git a/kernel/audit.c b/kernel/audit.c index 902962ea9be6..ce90ea8373d3 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1190,9 +1190,6 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) struct audit_buffer *ab; u16 msg_type = nlh->nlmsg_type; struct audit_sig_info *sig_data; - char *ctx = NULL; - u32 len; - struct lsmcontext scaff; /* scaffolding */ err = audit_netlink_ok(skb, msg_type); if (err) @@ -1440,33 +1437,34 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) kfree(new); break; } - case AUDIT_SIGNAL_INFO: - len = 0; + case AUDIT_SIGNAL_INFO: { + struct lsmcontext context = { }; + int len = 0; + if (lsmblob_is_set(&audit_sig_lsm)) { - err = security_secid_to_secctx(&audit_sig_lsm, &ctx, - &len); + err = security_secid_to_secctx(&audit_sig_lsm, + &context); if (err) return err; } - sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); + sig_data = kmalloc(sizeof(*sig_data) + context.len, GFP_KERNEL); if (!sig_data) { - if (lsmblob_is_set(&audit_sig_lsm)) { - lsmcontext_init(&scaff, ctx, len, 0); - security_release_secctx(&scaff); - } + if (lsmblob_is_set(&audit_sig_lsm)) + security_release_secctx(&context); return -ENOMEM; } sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); sig_data->pid = audit_sig_pid; if (lsmblob_is_set(&audit_sig_lsm)) { - memcpy(sig_data->ctx, ctx, len); - lsmcontext_init(&scaff, ctx, len, 0); - security_release_secctx(&scaff); + len = context.len; + memcpy(sig_data->ctx, context.context, len); + security_release_secctx(&context); } audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0, sig_data, sizeof(*sig_data) + len); kfree(sig_data); break; + } case AUDIT_TTY_GET: { struct audit_tty_status s; unsigned int t; @@ -2132,26 +2130,23 @@ void audit_log_key(struct audit_buffer *ab, char *key) int audit_log_task_context(struct audit_buffer *ab) { - char *ctx = NULL; - unsigned len; int error; struct lsmblob blob; - struct lsmcontext scaff; /* scaffolding */ + struct lsmcontext context; security_task_getsecid(current, &blob); if (!lsmblob_is_set(&blob)) return 0; - error = security_secid_to_secctx(&blob, &ctx, &len); + error = security_secid_to_secctx(&blob, &context); if (error) { if (error != -EINVAL) goto error_path; return 0; } - audit_log_format(ab, " subj=%s", ctx); - lsmcontext_init(&scaff, ctx, len, 0); - security_release_secctx(&scaff); + audit_log_format(ab, " subj=%s", context.context); + security_release_secctx(&context); return 0; error_path: diff --git a/kernel/auditsc.c b/kernel/auditsc.c index a73253515bc9..de2b2ecb3aea 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -998,9 +998,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid, struct lsmblob *blob, char *comm) { struct audit_buffer *ab; - struct lsmcontext lsmcxt; - char *ctx = NULL; - u32 len; + struct lsmcontext lsmctx; int rc = 0; ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID); @@ -1011,13 +1009,12 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid, from_kuid(&init_user_ns, auid), from_kuid(&init_user_ns, uid), sessionid); if (lsmblob_is_set(blob)) { - if (security_secid_to_secctx(blob, &ctx, &len)) { + if (security_secid_to_secctx(blob, &lsmctx)) { audit_log_format(ab, " obj=(none)"); rc = 1; } else { - audit_log_format(ab, " obj=%s", ctx); - lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/ - security_release_secctx(&lsmcxt); + audit_log_format(ab, " obj=%s", lsmctx.context); + security_release_secctx(&lsmctx); } } audit_log_format(ab, " ocomm="); @@ -1230,7 +1227,6 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) static void show_special(struct audit_context *context, int *call_panic) { - struct lsmcontext lsmcxt; struct audit_buffer *ab; int i; @@ -1254,17 +1250,15 @@ static void show_special(struct audit_context *context, int *call_panic) from_kgid(&init_user_ns, context->ipc.gid), context->ipc.mode); if (osid) { - char *ctx = NULL; - u32 len; + struct lsmcontext lsmcxt; struct lsmblob blob; lsmblob_init(&blob, osid); - if (security_secid_to_secctx(&blob, &ctx, &len)) { + if (security_secid_to_secctx(&blob, &lsmcxt)) { audit_log_format(ab, " osid=%u", osid); *call_panic = 1; } else { - audit_log_format(ab, " obj=%s", ctx); - lsmcontext_init(&lsmcxt, ctx, len, 0); + audit_log_format(ab, " obj=%s", lsmcxt.context); security_release_secctx(&lsmcxt); } } @@ -1411,20 +1405,17 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n, MAJOR(n->rdev), MINOR(n->rdev)); if (n->osid != 0) { - char *ctx = NULL; - u32 len; struct lsmblob blob; - struct lsmcontext lsmcxt; + struct lsmcontext lsmctx; lsmblob_init(&blob, n->osid); - if (security_secid_to_secctx(&blob, &ctx, &len)) { + if (security_secid_to_secctx(&blob, &lsmctx)) { audit_log_format(ab, " osid=%u", n->osid); if (call_panic) *call_panic = 2; } else { - audit_log_format(ab, " obj=%s", ctx); - lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */ - security_release_secctx(&lsmcxt); + audit_log_format(ab, " obj=%s", lsmctx.context); + security_release_secctx(&lsmctx); } } diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index a7e4c1b34b6c..ae073b642fa7 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -132,8 +132,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb) { struct lsmcontext context; struct lsmblob lb; - char *secdata; - u32 seclen, secid; + u32 secid; int err; err = security_socket_getpeersec_dgram(NULL, skb, &secid); @@ -141,12 +140,11 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb) return; lsmblob_init(&lb, secid); - err = security_secid_to_secctx(&lb, &secdata, &seclen); + err = security_secid_to_secctx(&lb, &context); if (err) return; - put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata); - lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */ + put_cmsg(msg, SOL_IP, SCM_SECURITY, context.len, context.context); security_release_secctx(&context); } diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 3b9cf2a1fed7..42570b8da17a 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -336,8 +336,7 @@ static int ctnetlink_dump_mark(struct sk_buff *skb, const struct nf_conn *ct) static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct) { struct nlattr *nest_secctx; - int len, ret; - char *secctx; + int ret; struct lsmblob blob; struct lsmcontext context; @@ -345,7 +344,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct) * security_secid_to_secctx() will know which security module * to use to create the secctx. */ lsmblob_init(&blob, ct->secmark); - ret = security_secid_to_secctx(&blob, &secctx, &len); + ret = security_secid_to_secctx(&blob, &context); if (ret) return 0; @@ -354,13 +353,12 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct) if (!nest_secctx) goto nla_put_failure; - if (nla_put_string(skb, CTA_SECCTX_NAME, secctx)) + if (nla_put_string(skb, CTA_SECCTX_NAME, context.context)) goto nla_put_failure; nla_nest_end(skb, nest_secctx); ret = 0; nla_put_failure: - lsmcontext_init(&context, secctx, len, 0); /* scaffolding */ security_release_secctx(&context); return ret; } @@ -660,15 +658,15 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct) #ifdef CONFIG_NF_CONNTRACK_SECMARK int len, ret; struct lsmblob blob; + struct lsmcontext context; - /* lsmblob_init() puts ct->secmark into all of the secids in blob. - * security_secid_to_secctx() will know which security module - * to use to create the secctx. */ - lsmblob_init(&blob, ct->secmark); - ret = security_secid_to_secctx(&blob, NULL, &len); + ret = security_secid_to_secctx(&blob, &context); if (ret) return 0; + len = context.len; + security_release_secctx(&context); + return nla_total_size(0) /* CTA_SECCTX */ + nla_total_size(sizeof(char) * len); /* CTA_SECCTX_NAME */ #else diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c index e2bdc851a477..c6112960fc73 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -173,19 +173,16 @@ static void ct_seq_stop(struct seq_file *s, void *v) static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct) { int ret; - u32 len; - char *secctx; struct lsmblob blob; struct lsmcontext context; lsmblob_init(&blob, ct->secmark); - ret = security_secid_to_secctx(&blob, &secctx, &len); + ret = security_secid_to_secctx(&blob, &context); if (ret) return; - seq_printf(s, "secctx=%s ", secctx); + seq_printf(s, "secctx=%s ", context.context); - lsmcontext_init(&context, secctx, len, 0); /* scaffolding */ security_release_secctx(&context); } #else diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index dcc31cb7f287..84be5a49a157 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -306,6 +306,7 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata) u32 seclen = 0; #if IS_ENABLED(CONFIG_NETWORK_SECMARK) struct lsmblob blob; + struct lsmcontext context = { }; if (!skb || !sk_fullsock(skb->sk)) return 0; @@ -317,10 +318,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata) * blob. security_secid_to_secctx() will know which security * module to use to create the secctx. */ lsmblob_init(&blob, skb->secmark); - security_secid_to_secctx(&blob, secdata, &seclen); + security_secid_to_secctx(&blob, &context); + *secdata = context.context; } read_unlock_bh(&skb->sk->sk_callback_lock); + seclen = context.len; #endif return seclen; } diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c index 32b6eea7ba0c..aa53a94115f4 100644 --- a/net/netlabel/netlabel_unlabeled.c +++ b/net/netlabel/netlabel_unlabeled.c @@ -375,8 +375,6 @@ int netlbl_unlhsh_add(struct net *net, struct netlbl_unlhsh_iface *iface; struct audit_buffer *audit_buf = NULL; struct lsmcontext context; - char *secctx = NULL; - u32 secctx_len; struct lsmblob blob; if (addr_len != sizeof(struct in_addr) && @@ -444,12 +442,9 @@ int netlbl_unlhsh_add(struct net *net, * security_secid_to_secctx() will know which security module * to use to create the secctx. */ lsmblob_init(&blob, secid); - if (security_secid_to_secctx(&blob, - &secctx, - &secctx_len) == 0) { - audit_log_format(audit_buf, " sec_obj=%s", secctx); - /* scaffolding */ - lsmcontext_init(&context, secctx, secctx_len, 0); + if (security_secid_to_secctx(&blob, &context) == 0) { + audit_log_format(audit_buf, " sec_obj=%s", + context.context); security_release_secctx(&context); } audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0); @@ -482,8 +477,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net, struct audit_buffer *audit_buf; struct net_device *dev; struct lsmcontext context; - char *secctx; - u32 secctx_len; struct lsmblob blob; spin_lock(&netlbl_unlhsh_lock); @@ -510,11 +503,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net, if (entry != NULL) lsmblob_init(&blob, entry->secid); if (entry != NULL && - security_secid_to_secctx(&blob, - &secctx, &secctx_len) == 0) { - audit_log_format(audit_buf, " sec_obj=%s", secctx); - /* scaffolding */ - lsmcontext_init(&context, secctx, secctx_len, 0); + security_secid_to_secctx(&blob, &context) == 0) { + audit_log_format(audit_buf, " sec_obj=%s", + context.context); security_release_secctx(&context); } audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0); @@ -553,8 +544,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net, struct audit_buffer *audit_buf; struct net_device *dev; struct lsmcontext context; - char *secctx; - u32 secctx_len; struct lsmblob blob; spin_lock(&netlbl_unlhsh_lock); @@ -580,10 +569,9 @@ static int netlbl_unlhsh_remove_addr6(struct net *net, if (entry != NULL) lsmblob_init(&blob, entry->secid); if (entry != NULL && - security_secid_to_secctx(&blob, - &secctx, &secctx_len) == 0) { - audit_log_format(audit_buf, " sec_obj=%s", secctx); - lsmcontext_init(&context, secctx, secctx_len, 0); + security_secid_to_secctx(&blob, &context) == 0) { + audit_log_format(audit_buf, " sec_obj=%s", + context.context); security_release_secctx(&context); } audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0); @@ -1106,8 +1094,6 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd, struct lsmcontext context; void *data; u32 secid; - char *secctx; - u32 secctx_len; struct lsmblob blob; data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid, @@ -1167,15 +1153,13 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd, * security_secid_to_secctx() will know which security module * to use to create the secctx. */ lsmblob_init(&blob, secid); - ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len); + ret_val = security_secid_to_secctx(&blob, &context); if (ret_val != 0) goto list_cb_failure; ret_val = nla_put(cb_arg->skb, NLBL_UNLABEL_A_SECCTX, - secctx_len, - secctx); - /* scaffolding */ - lsmcontext_init(&context, secctx, secctx_len, 0); + context.len, + context.context); security_release_secctx(&context); if (ret_val != 0) goto list_cb_failure; diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c index ef139d8ae7cd..951ba0639d20 100644 --- a/net/netlabel/netlabel_user.c +++ b/net/netlabel/netlabel_user.c @@ -85,8 +85,6 @@ struct audit_buffer *netlbl_audit_start_common(int type, { struct audit_buffer *audit_buf; struct lsmcontext context; - char *secctx; - u32 secctx_len; struct lsmblob blob; if (audit_enabled == AUDIT_OFF) @@ -102,9 +100,8 @@ struct audit_buffer *netlbl_audit_start_common(int type, lsmblob_init(&blob, audit_info->secid); if (audit_info->secid != 0 && - security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) { - audit_log_format(audit_buf, " subj=%s", secctx); - lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/ + security_secid_to_secctx(&blob, &context) == 0) { + audit_log_format(audit_buf, " subj=%s", context.context); security_release_secctx(&context); } diff --git a/security/security.c b/security/security.c index 904ae6c46be0..aab6d3f86e4a 100644 --- a/security/security.c +++ b/security/security.c @@ -2252,18 +2252,22 @@ int security_ismaclabel(const char *name) } EXPORT_SYMBOL(security_ismaclabel); -int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen) +int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp) { struct security_hook_list *hp; int ilsm = lsm_task_ilsm(current); + memset(cp, 0, sizeof(*cp)); + hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) { if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) continue; - if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) + if (ilsm == LSMBLOB_INVALID || ilsm == hp->lsmid->slot) { + cp->slot = hp->lsmid->slot; return hp->hook.secid_to_secctx( blob->secid[hp->lsmid->slot], - secdata, seclen); + &cp->context, &cp->len); + } } return LSM_RET_DEFAULT(secid_to_secctx); -- 2.25.4

Change netlink netfilter interfaces to use lsmcontext pointers, and remove scaffolding. Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; Acked-by: Stephen Smalley <sds(a)tycho.nsa.gov&gt; Acked-by: Pablo Neira Ayuso <pablo(a)netfilter.org&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: netdev(a)vger.kernel.org Cc: netfilter-devel(a)vger.kernel.org --- net/netfilter/nfnetlink_queue.c | 37 +++++++++++++-------------------- 1 file changed, 14 insertions(+), 23 deletions(-) diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 84be5a49a157..0d8b83d84422 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -301,15 +301,13 @@ static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk) return -1; } -static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata) +static void nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context) { - u32 seclen = 0; #if IS_ENABLED(CONFIG_NETWORK_SECMARK) struct lsmblob blob; - struct lsmcontext context = { }; if (!skb || !sk_fullsock(skb->sk)) - return 0; + return; read_lock_bh(&skb->sk->sk_callback_lock); @@ -318,14 +316,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata) * blob. security_secid_to_secctx() will know which security * module to use to create the secctx. */ lsmblob_init(&blob, skb->secmark); - security_secid_to_secctx(&blob, &context); - *secdata = context.context; + security_secid_to_secctx(&blob, context); } read_unlock_bh(&skb->sk->sk_callback_lock); - seclen = context.len; #endif - return seclen; + return; } static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry) @@ -398,12 +394,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, struct net_device *indev; struct net_device *outdev; struct nf_conn *ct = NULL; + struct lsmcontext context = { }; enum ip_conntrack_info ctinfo; struct nfnl_ct_hook *nfnl_ct; bool csum_verify; - struct lsmcontext scaff; /* scaffolding */ - char *secdata = NULL; - u32 seclen = 0; size = nlmsg_total_size(sizeof(struct nfgenmsg)) + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr)) @@ -469,9 +463,9 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, } if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) { - seclen = nfqnl_get_sk_secctx(entskb, &secdata); - if (seclen) - size += nla_total_size(seclen); + nfqnl_get_sk_secctx(entskb, &context); + if (context.len) + size += nla_total_size(context.len); } skb = alloc_skb(size, GFP_ATOMIC); @@ -604,7 +598,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, nfqnl_put_sk_uidgid(skb, entskb->sk) < 0) goto nla_put_failure; - if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata)) + if (context.len && + nla_put(skb, NFQA_SECCTX, context.len, context.context)) goto nla_put_failure; if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0) @@ -632,10 +627,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, } nlh->nlmsg_len = skb->len; - if (seclen) { - lsmcontext_init(&scaff, secdata, seclen, 0); - security_release_secctx(&scaff); - } + if (context.len) + security_release_secctx(&context); return skb; nla_put_failure: @@ -643,10 +636,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, kfree_skb(skb); net_err_ratelimited("nf_queue: error creating packet message\n"); nlmsg_failure: - if (seclen) { - lsmcontext_init(&scaff, secdata, seclen, 0); - security_release_secctx(&scaff); - } + if (context.len) + security_release_secctx(&context); return NULL; } -- 2.25.4

Verify that the tasks on the ends of a binder transaction use the same "display" security module. This prevents confusion of security "contexts". Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; Acked-by: Stephen Smalley <sds(a)tycho.nsa.gov&gt; Acked-by: Paul Moore <paul(a)paul-moore.com&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; --- security/security.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/security/security.c b/security/security.c index ba39b9b13e08..03fb8a702f64 100644 --- a/security/security.c +++ b/security/security.c @@ -834,9 +834,38 @@ int security_binder_set_context_mgr(struct task_struct *mgr) return call_int_hook(binder_set_context_mgr, 0, mgr); } +/** + * security_binder_transaction - Binder driver transaction check + * @from: source of the transaction + * @to: destination of the transaction + * + * Verify that the tasks have the same LSM "display", then + * call the security module hooks. + * + * Returns -EINVAL if the displays don't match, or the + * result of the security module checks. + */ int security_binder_transaction(struct task_struct *from, struct task_struct *to) { + int from_ilsm = lsm_task_ilsm(from); + int to_ilsm = lsm_task_ilsm(to); + + /* + * If the ilsm is LSMBLOB_INVALID the first module that has + * an entry is used. This will be in the 0 slot. + * + * This is currently only required if the server has requested + * peer contexts, but it would be unwieldly to have too much of + * the binder driver detail here. + */ + if (from_ilsm == LSMBLOB_INVALID) + from_ilsm = 0; + if (to_ilsm == LSMBLOB_INVALID) + to_ilsm = 0; + if (from_ilsm != to_ilsm) + return -EINVAL; + return call_int_hook(binder_transaction, 0, from, to); } -- 2.25.4

On 2021-01-26 08:41, Casey Schaufler wrote: This has been minorly bothering me for several revisions... Is there a way for the development/authorship to be accurately reflected if/when this patch is merged before the contid patch set? - RGB -- Richard Guy Briggs <rgb(a)redhat.com&gt; Sr. S/W Engineer, Kernel Security, Base Operating Systems Remote, Ottawa, Red Hat Canada IRC: rgb, SunRaycer Voice: +1.647.777.2635, Internal: (81) 32635

Create a new audit record type to contain the subject information when there are multiple security modules that require such data. This record is linked with the same timestamp and serial number using the audit_alloc_local() mechanism. The record is produced only in cases where there is more than one security module with a process "context". In cases where this record is produced the subj= fields of other records in the audit event will be set to "subj=?". An example of the MAC_TASK_CONTEXTS (1420) record is: type=UNKNOWN[1420] msg=audit(1600880931.832:113) subj_apparmor==unconfined subj_smack=_ There will be a subj_$LSM= entry for each security module LSM that supports the secid_to_secctx and secctx_to_secid hooks. The BPF security module implements secid/secctx translation hooks, so it has to be considered to provide a secctx even though it may not actually do so. Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; To: paul(a)paul-moore.com To: linux-audit(a)redhat.com To: rgb(a)redhat.com Cc: netdev(a)vger.kernel.org --- drivers/android/binder.c | 2 +- include/linux/audit.h | 24 ++++++++ include/linux/security.h | 16 ++++- include/net/netlabel.h | 3 +- include/net/scm.h | 2 +- include/net/xfrm.h | 13 +++- include/uapi/linux/audit.h | 1 + kernel/audit.c | 80 ++++++++++++++++++------- kernel/audit.h | 3 + kernel/auditfilter.c | 6 +- kernel/auditsc.c | 75 ++++++++++++++++++++--- net/ipv4/ip_sockglue.c | 2 +- net/netfilter/nf_conntrack_netlink.c | 4 +- net/netfilter/nf_conntrack_standalone.c | 2 +- net/netfilter/nfnetlink_queue.c | 2 +- net/netlabel/netlabel_domainhash.c | 4 +- net/netlabel/netlabel_unlabeled.c | 24 ++++---- net/netlabel/netlabel_user.c | 20 ++++--- net/netlabel/netlabel_user.h | 6 +- net/xfrm/xfrm_policy.c | 10 ++-- net/xfrm/xfrm_state.c | 20 ++++--- security/integrity/ima/ima_api.c | 7 ++- security/integrity/integrity_audit.c | 6 +- security/security.c | 46 +++++++++----- security/smack/smackfs.c | 3 +- 25 files changed, 274 insertions(+), 107 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 4c810ea52ab7..28f573d46391 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2700,7 +2700,7 @@ static void binder_transaction(struct binder_proc *proc, size_t added_size; security_task_getsecid(proc->tsk, &blob); - ret = security_secid_to_secctx(&blob, &lsmctx); + ret = security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_DISPLAY); if (ret) { return_error = BR_FAILED_REPLY; return_error_param = ret; diff --git a/include/linux/audit.h b/include/linux/audit.h index 97cd7471e572..229cd71fbf09 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -164,6 +164,8 @@ extern struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp extern __printf(2, 3) void audit_log_format(struct audit_buffer *ab, const char *fmt, ...); extern void audit_log_end(struct audit_buffer *ab); +extern void audit_log_end_local(struct audit_buffer *ab, + struct audit_context *context); extern bool audit_string_contains_control(const char *string, size_t len); extern void audit_log_n_hex(struct audit_buffer *ab, @@ -188,6 +190,7 @@ extern void audit_log_lost(const char *message); extern int audit_log_task_context(struct audit_buffer *ab); extern void audit_log_task_info(struct audit_buffer *ab); +extern void audit_log_lsm(struct audit_context *context); extern int audit_update_lsm_rules(void); @@ -226,6 +229,9 @@ void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) { } static inline void audit_log_end(struct audit_buffer *ab) { } +static inline void audit_log_end_local(struct audit_buffer *ab, + struct audit_context *context) +{ } static inline void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, size_t len) { } @@ -252,6 +258,8 @@ static inline int audit_log_task_context(struct audit_buffer *ab) } static inline void audit_log_task_info(struct audit_buffer *ab) { } +static void audit_log_lsm(struct audit_context *context) +{ } static inline kuid_t audit_get_loginuid(struct task_struct *tsk) { @@ -291,6 +299,7 @@ extern int audit_alloc(struct task_struct *task); extern void __audit_free(struct task_struct *task); extern struct audit_context *audit_alloc_local(gfp_t gfpflags); extern void audit_free_context(struct audit_context *context); +extern void audit_free_local(struct audit_context *context); extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1, unsigned long a2, unsigned long a3); extern void __audit_syscall_exit(int ret_success, long ret_value); @@ -386,6 +395,19 @@ static inline void audit_ptrace(struct task_struct *t) __audit_ptrace(t); } +static inline struct audit_context *audit_alloc_for_lsm(gfp_t gfp) +{ + struct audit_context *context = audit_context(); + + if (context) + return context; + + if (lsm_multiple_contexts()) + return audit_alloc_local(gfp); + + return NULL; +} + /* Private API (for audit.c only) */ extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp); extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode); @@ -560,6 +582,8 @@ extern int audit_signals; } static inline void audit_free_context(struct audit_context *context) { } +static inline void audit_free_local(struct audit_context *context) +{ } static inline int audit_alloc(struct task_struct *task) { return 0; diff --git a/include/linux/security.h b/include/linux/security.h index e5740e08bc0c..18dd3218f1c0 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -182,6 +182,8 @@ struct lsmblob { #define LSMBLOB_INVALID -1 /* Not a valid LSM slot number */ #define LSMBLOB_NEEDED -2 /* Slot requested on initialization */ #define LSMBLOB_NOT_NEEDED -3 /* Slot not requested */ +#define LSMBLOB_DISPLAY -4 /* Use the "display" slot */ +#define LSMBLOB_FIRST -5 /* Use the default "display" slot */ /** * lsmblob_init - initialize an lsmblob structure @@ -248,6 +250,15 @@ static inline u32 lsmblob_value(const struct lsmblob *blob) return 0; } +static inline bool lsm_multiple_contexts(void) +{ +#ifdef CONFIG_SECURITY + return lsm_slot_to_name(1) != NULL; +#else + return false; +#endif +} + /* These functions are in security/commoncap.c */ extern int cap_capable(const struct cred *cred, struct user_namespace *ns, int cap, unsigned int opts); @@ -564,7 +575,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value, size_t size); int security_netlink_send(struct sock *sk, struct sk_buff *skb); int security_ismaclabel(const char *name); -int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp); +int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp, + int display); int security_secctx_to_secid(const char *secdata, u32 seclen, struct lsmblob *blob); void security_release_secctx(struct lsmcontext *cp); @@ -1390,7 +1402,7 @@ static inline int security_ismaclabel(const char *name) } static inline int security_secid_to_secctx(struct lsmblob *blob, - struct lsmcontext *cp) + struct lsmcontext *cp, int display) { return -EOPNOTSUPP; } diff --git a/include/net/netlabel.h b/include/net/netlabel.h index 73fc25b4042b..9bc1f969a25d 100644 --- a/include/net/netlabel.h +++ b/include/net/netlabel.h @@ -97,7 +97,8 @@ struct calipso_doi; /* NetLabel audit information */ struct netlbl_audit { - u32 secid; + struct audit_context *localcontext; + struct lsmblob lsmdata; kuid_t loginuid; unsigned int sessionid; }; diff --git a/include/net/scm.h b/include/net/scm.h index b77a52f93389..f4d567d4885e 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -101,7 +101,7 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc * and the infrastructure will know which it is. */ lsmblob_init(&lb, scm->secid); - err = security_secid_to_secctx(&lb, &context); + err = security_secid_to_secctx(&lb, &context, LSMBLOB_DISPLAY); if (!err) { put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, context.len, diff --git a/include/net/xfrm.h b/include/net/xfrm.h index b2a06f10b62c..bfe3ba2a5233 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -669,13 +669,22 @@ struct xfrm_spi_skb_cb { #define XFRM_SPI_SKB_CB(__skb) ((struct xfrm_spi_skb_cb *)&((__skb)->cb[0])) #ifdef CONFIG_AUDITSYSCALL -static inline struct audit_buffer *xfrm_audit_start(const char *op) +static inline struct audit_buffer *xfrm_audit_start(const char *op, + struct audit_context **lac) { + struct audit_context *context; struct audit_buffer *audit_buf = NULL; if (audit_enabled == AUDIT_OFF) return NULL; - audit_buf = audit_log_start(audit_context(), GFP_ATOMIC, + context = audit_context(); + if (lac != NULL) { + if (lsm_multiple_contexts() && context == NULL) + context = audit_alloc_local(GFP_ATOMIC); + *lac = context; + } + + audit_buf = audit_log_start(context, GFP_ATOMIC, AUDIT_MAC_IPSEC_EVENT); if (audit_buf == NULL) return NULL; diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h index cd2d8279a5e4..2a63720e56f6 100644 --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -139,6 +139,7 @@ #define AUDIT_MAC_UNLBL_STCDEL 1417 /* NetLabel: del a static label */ #define AUDIT_MAC_CALIPSO_ADD 1418 /* NetLabel: add CALIPSO DOI entry */ #define AUDIT_MAC_CALIPSO_DEL 1419 /* NetLabel: del CALIPSO DOI entry */ +#define AUDIT_MAC_TASK_CONTEXTS 1420 /* Multiple LSM contexts */ #define AUDIT_FIRST_KERN_ANOM_MSG 1700 #define AUDIT_LAST_KERN_ANOM_MSG 1799 diff --git a/kernel/audit.c b/kernel/audit.c index ce90ea8373d3..732ce576ed89 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -386,10 +386,12 @@ void audit_log_lost(const char *message) static int audit_log_config_change(char *function_name, u32 new, u32 old, int allow_changes) { + struct audit_context *context; struct audit_buffer *ab; int rc = 0; - ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE); + context = audit_alloc_for_lsm(GFP_KERNEL); + ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONFIG_CHANGE); if (unlikely(!ab)) return rc; audit_log_format(ab, "op=set %s=%u old=%u ", function_name, new, old); @@ -398,7 +400,7 @@ static int audit_log_config_change(char *function_name, u32 new, u32 old, if (rc) allow_changes = 0; /* Something weird, deny request */ audit_log_format(ab, " res=%d", allow_changes); - audit_log_end(ab); + audit_log_end_local(ab, context); return rc; } @@ -1072,12 +1074,6 @@ static void audit_log_common_recv_msg(struct audit_context *context, audit_log_task_context(*ab); } -static inline void audit_log_user_recv_msg(struct audit_buffer **ab, - u16 msg_type) -{ - audit_log_common_recv_msg(NULL, ab, msg_type); -} - int is_audit_feature_set(int i) { return af.features & AUDIT_FEATURE_TO_MASK(i); @@ -1110,6 +1106,7 @@ static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d", audit_feature_names[which], !!old_feature, !!new_feature, !!old_lock, !!new_lock, res); + audit_log_lsm(ab->ctx); audit_log_end(ab); } @@ -1190,6 +1187,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) struct audit_buffer *ab; u16 msg_type = nlh->nlmsg_type; struct audit_sig_info *sig_data; + struct audit_context *lcontext; err = audit_netlink_ok(skb, msg_type); if (err) @@ -1357,7 +1355,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (err) break; } - audit_log_user_recv_msg(&ab, msg_type); + lcontext = audit_alloc_for_lsm(GFP_KERNEL); + audit_log_common_recv_msg(lcontext, &ab, msg_type); if (msg_type != AUDIT_USER_TTY) { /* ensure NULL termination */ str[data_len - 1] = '\0'; @@ -1370,7 +1369,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) data_len--; audit_log_n_untrustedstring(ab, str, data_len); } - audit_log_end(ab); + audit_log_end_local(ab, lcontext); } break; case AUDIT_ADD_RULE: @@ -1378,13 +1377,14 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (data_len < sizeof(struct audit_rule_data)) return -EINVAL; if (audit_enabled == AUDIT_LOCKED) { - audit_log_common_recv_msg(audit_context(), &ab, + lcontext = audit_alloc_for_lsm(GFP_KERNEL); + audit_log_common_recv_msg(lcontext, &ab, AUDIT_CONFIG_CHANGE); audit_log_format(ab, " op=%s audit_enabled=%d res=0", msg_type == AUDIT_ADD_RULE ? "add_rule" : "remove_rule", audit_enabled); - audit_log_end(ab); + audit_log_end_local(ab, lcontext); return -EPERM; } err = audit_rule_change(msg_type, seq, data, data_len); @@ -1394,10 +1394,10 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) break; case AUDIT_TRIM: audit_trim_trees(); - audit_log_common_recv_msg(audit_context(), &ab, - AUDIT_CONFIG_CHANGE); + lcontext = audit_alloc_for_lsm(GFP_KERNEL); + audit_log_common_recv_msg(lcontext, &ab, AUDIT_CONFIG_CHANGE); audit_log_format(ab, " op=trim res=1"); - audit_log_end(ab); + audit_log_end_local(ab, lcontext); break; case AUDIT_MAKE_EQUIV: { void *bufp = data; @@ -1425,6 +1425,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) /* OK, here comes... */ err = audit_tag_tree(old, new); + lcontext = audit_alloc_for_lsm(GFP_KERNEL); audit_log_common_recv_msg(audit_context(), &ab, AUDIT_CONFIG_CHANGE); audit_log_format(ab, " op=make_equiv old="); @@ -1432,7 +1433,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) audit_log_format(ab, " new="); audit_log_untrustedstring(ab, new); audit_log_format(ab, " res=%d", !err); - audit_log_end(ab); + audit_log_end_local(ab, lcontext); kfree(old); kfree(new); break; @@ -1443,7 +1444,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (lsmblob_is_set(&audit_sig_lsm)) { err = security_secid_to_secctx(&audit_sig_lsm, - &context); + &context, LSMBLOB_FIRST); if (err) return err; } @@ -1498,13 +1499,14 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) old.enabled = t & AUDIT_TTY_ENABLE; old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD); + lcontext = audit_alloc_for_lsm(GFP_KERNEL); audit_log_common_recv_msg(audit_context(), &ab, AUDIT_CONFIG_CHANGE); audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d" " old-log_passwd=%d new-log_passwd=%d res=%d", old.enabled, s.enabled, old.log_passwd, s.log_passwd, !err); - audit_log_end(ab); + audit_log_end_local(ab, lcontext); break; } default: @@ -1550,6 +1552,7 @@ static void audit_receive(struct sk_buff *skb) /* Log information about who is connecting to the audit multicast socket */ static void audit_log_multicast(int group, const char *op, int err) { + struct audit_context *context; const struct cred *cred; struct tty_struct *tty; char comm[sizeof(current->comm)]; @@ -1558,7 +1561,8 @@ static void audit_log_multicast(int group, const char *op, int err) if (!audit_enabled) return; - ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_EVENT_LISTENER); + context = audit_alloc_for_lsm(GFP_KERNEL); + ab = audit_log_start(context, GFP_KERNEL, AUDIT_EVENT_LISTENER); if (!ab) return; @@ -1576,7 +1580,7 @@ static void audit_log_multicast(int group, const char *op, int err) audit_log_untrustedstring(ab, get_task_comm(comm, current)); audit_log_d_path_exe(ab, current->mm); /* exe= */ audit_log_format(ab, " nl-mcgrp=%d op=%s res=%d", group, op, !err); - audit_log_end(ab); + audit_log_end_local(ab, context); } /* Run custom bind function on netlink socket group connect or bind requests. */ @@ -2138,7 +2142,19 @@ int audit_log_task_context(struct audit_buffer *ab) if (!lsmblob_is_set(&blob)) return 0; - error = security_secid_to_secctx(&blob, &context); + /* + * If there is more than one security module that has a + * subject "context" it's necessary to put the subject data + * into a separate record to maintain compatibility. + */ + if (lsm_multiple_contexts()) { + if (ab->ctx) + ab->ctx->lsm = blob; + audit_log_format(ab, " subj=?"); + return 0; + } + + error = security_secid_to_secctx(&blob, &context, LSMBLOB_FIRST); if (error) { if (error != -EINVAL) goto error_path; @@ -2224,6 +2240,7 @@ void audit_log_task_info(struct audit_buffer *ab) audit_log_untrustedstring(ab, get_task_comm(comm, current)); audit_log_d_path_exe(ab, current->mm); audit_log_task_context(ab); + audit_log_lsm(ab->ctx); } EXPORT_SYMBOL(audit_log_task_info); @@ -2274,6 +2291,7 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid, unsigned int oldsessionid, unsigned int sessionid, int rc) { + struct audit_context *context; struct audit_buffer *ab; uid_t uid, oldloginuid, loginuid; struct tty_struct *tty; @@ -2281,7 +2299,8 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid, if (!audit_enabled) return; - ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_LOGIN); + context = audit_alloc_for_lsm(GFP_KERNEL); + ab = audit_log_start(context, GFP_KERNEL, AUDIT_LOGIN); if (!ab) return; @@ -2296,7 +2315,7 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid, oldloginuid, loginuid, tty ? tty_name(tty) : "(none)", oldsessionid, sessionid, !rc); audit_put_tty(tty); - audit_log_end(ab); + audit_log_end_local(ab, context); } /** @@ -2396,6 +2415,21 @@ void audit_log_end(struct audit_buffer *ab) audit_buffer_free(ab); } +/** + * audit_log_end_local - end one audit record with local context + * @ab: the audit_buffer + * @context: the local context + * + * Emit an LSM context record if appropriate, then end the audit event + * in the usual way. + */ +void audit_log_end_local(struct audit_buffer *ab, struct audit_context *context) +{ + audit_log_end(ab); + audit_log_lsm_common(context); + audit_free_local(context); +} + /** * audit_log - Log an audit record * @ctx: audit context diff --git a/kernel/audit.h b/kernel/audit.h index 3f2285e1c6e0..4f245c3dac0c 100644 --- a/kernel/audit.h +++ b/kernel/audit.h @@ -100,6 +100,7 @@ struct audit_context { int dummy; /* must be the first element */ int in_syscall; /* 1 if task is in a syscall */ bool local; /* local context needed */ + bool lsmdone; /* multiple security reported */ enum audit_state state, current_state; unsigned int serial; /* serial number for record */ int major; /* syscall number */ @@ -131,6 +132,7 @@ struct audit_context { kgid_t gid, egid, sgid, fsgid; unsigned long personality; int arch; + struct lsmblob lsm; pid_t target_pid; kuid_t target_auid; @@ -201,6 +203,7 @@ struct audit_context { extern bool audit_ever_enabled; extern void audit_log_session_info(struct audit_buffer *ab); +extern void audit_log_lsm_common(struct audit_context *context); extern int auditd_test_task(struct task_struct *task); diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index 9e73a7961665..2b0a6fda767d 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -1098,12 +1098,14 @@ static void audit_list_rules(int seq, struct sk_buff_head *q) /* Log rule additions and removals */ static void audit_log_rule_change(char *action, struct audit_krule *rule, int res) { + struct audit_context *context; struct audit_buffer *ab; if (!audit_enabled) return; - ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE); + context = audit_alloc_for_lsm(GFP_KERNEL); + ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONFIG_CHANGE); if (!ab) return; audit_log_session_info(ab); @@ -1111,7 +1113,7 @@ static void audit_log_rule_change(char *action, struct audit_krule *rule, int re audit_log_format(ab, " op=%s", action); audit_log_key(ab, rule->filterkey); audit_log_format(ab, " list=%d res=%d", rule->listnr, res); - audit_log_end(ab); + audit_log_end_local(ab, context); } /** diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 479b3933d788..376adae15a9d 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -942,6 +942,7 @@ static inline struct audit_context *audit_alloc_context(enum audit_state state, INIT_LIST_HEAD(&context->names_list); context->fds[0] = -1; context->return_valid = AUDITSC_INVALID; + context->lsmdone = false; return context; } @@ -989,12 +990,11 @@ struct audit_context *audit_alloc_local(gfp_t gfpflags) context = audit_alloc_context(AUDIT_RECORD_CONTEXT, gfpflags); if (!context) { audit_log_lost("out of memory in audit_alloc_local"); - goto out; + return NULL; } context->serial = audit_serial(); ktime_get_coarse_real_ts64(&context->ctime); context->local = true; -out: return context; } EXPORT_SYMBOL(audit_alloc_local); @@ -1015,6 +1015,13 @@ void audit_free_context(struct audit_context *context) } EXPORT_SYMBOL(audit_free_context); +void audit_free_local(struct audit_context *context) +{ + if (context && context->local) + audit_free_context(context); +} +EXPORT_SYMBOL(audit_free_local); + static int audit_log_pid_context(struct audit_context *context, pid_t pid, kuid_t auid, kuid_t uid, unsigned int sessionid, @@ -1032,7 +1039,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid, from_kuid(&init_user_ns, auid), from_kuid(&init_user_ns, uid), sessionid); if (lsmblob_is_set(blob)) { - if (security_secid_to_secctx(blob, &lsmctx)) { + if (security_secid_to_secctx(blob, &lsmctx, LSMBLOB_FIRST)) { audit_log_format(ab, " obj=(none)"); rc = 1; } else { @@ -1277,7 +1284,8 @@ static void show_special(struct audit_context *context, int *call_panic) struct lsmblob blob; lsmblob_init(&blob, osid); - if (security_secid_to_secctx(&blob, &lsmcxt)) { + if (security_secid_to_secctx(&blob, &lsmcxt, + LSMBLOB_FIRST)) { audit_log_format(ab, " osid=%u", osid); *call_panic = 1; } else { @@ -1432,7 +1440,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n, struct lsmcontext lsmctx; lsmblob_init(&blob, n->osid); - if (security_secid_to_secctx(&blob, &lsmctx)) { + if (security_secid_to_secctx(&blob, &lsmctx, LSMBLOB_FIRST)) { audit_log_format(ab, " osid=%u", n->osid); if (call_panic) *call_panic = 2; @@ -1506,6 +1514,47 @@ static void audit_log_proctitle(void) audit_log_end(ab); } +void audit_log_lsm_common(struct audit_context *context) +{ + struct audit_buffer *ab; + struct lsmcontext lsmdata; + bool sep = false; + int error; + int i; + + if (!lsm_multiple_contexts() || context == NULL || + !lsmblob_is_set(&context->lsm)) + return; + + ab = audit_log_start(context, GFP_ATOMIC, AUDIT_MAC_TASK_CONTEXTS); + if (!ab) + return; /* audit_panic or being filtered */ + + for (i = 0; i < LSMBLOB_ENTRIES; i++) { + if (context->lsm.secid[i] == 0) + continue; + error = security_secid_to_secctx(&context->lsm, &lsmdata, i); + if (error && error != -EINVAL) { + audit_panic("error in audit_log_lsm"); + return; + } + + audit_log_format(ab, "%ssubj_%s=%s", sep ? " " : "", + lsm_slot_to_name(i), lsmdata.context); + sep = true; + + security_release_secctx(&lsmdata); + } + audit_log_end(ab); + context->lsmdone = true; +} + +void audit_log_lsm(struct audit_context *context) +{ + if (!context->lsmdone) + audit_log_lsm_common(context); +} + static void audit_log_exit(void) { int i, call_panic = 0; @@ -1540,6 +1589,8 @@ static void audit_log_exit(void) audit_log_key(ab, context->filterkey); audit_log_end(ab); + audit_log_lsm(context); + for (aux = context->aux; aux; aux = aux->next) { ab = audit_log_start(context, GFP_KERNEL, aux->type); @@ -1630,6 +1681,8 @@ static void audit_log_exit(void) audit_log_proctitle(); + audit_log_lsm(context); + /* Send end of event record to help user space know we are finished */ ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE); if (ab) @@ -2621,10 +2674,12 @@ void __audit_ntp_log(const struct audit_ntp_data *ad) void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries, enum audit_nfcfgop op, gfp_t gfp) { + struct audit_context *context; struct audit_buffer *ab; char comm[sizeof(current->comm)]; - ab = audit_log_start(audit_context(), gfp, AUDIT_NETFILTER_CFG); + context = audit_alloc_for_lsm(GFP_KERNEL); + ab = audit_log_start(context, gfp, AUDIT_NETFILTER_CFG); if (!ab) return; audit_log_format(ab, "table=%s family=%u entries=%u op=%s", @@ -2634,7 +2689,7 @@ void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries, audit_log_task_context(ab); /* subj= */ audit_log_format(ab, " comm="); audit_log_untrustedstring(ab, get_task_comm(comm, current)); - audit_log_end(ab); + audit_log_end_local(ab, context); } EXPORT_SYMBOL_GPL(__audit_log_nfcfg); @@ -2669,6 +2724,7 @@ static void audit_log_task(struct audit_buffer *ab) */ void audit_core_dumps(long signr) { + struct audit_context *context; struct audit_buffer *ab; if (!audit_enabled) @@ -2677,12 +2733,13 @@ void audit_core_dumps(long signr) if (signr == SIGQUIT) /* don't care for those */ return; - ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_ANOM_ABEND); + context = audit_alloc_for_lsm(GFP_KERNEL); + ab = audit_log_start(context, GFP_KERNEL, AUDIT_ANOM_ABEND); if (unlikely(!ab)) return; audit_log_task(ab); audit_log_format(ab, " sig=%ld res=1", signr); - audit_log_end(ab); + audit_log_end_local(ab, context); } /** diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index ae073b642fa7..5c0029a3a595 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -140,7 +140,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb) return; lsmblob_init(&lb, secid); - err = security_secid_to_secctx(&lb, &context); + err = security_secid_to_secctx(&lb, &context, LSMBLOB_DISPLAY); if (err) return; diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 42570b8da17a..c8facca4818c 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -344,7 +344,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct) * security_secid_to_secctx() will know which security module * to use to create the secctx. */ lsmblob_init(&blob, ct->secmark); - ret = security_secid_to_secctx(&blob, &context); + ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY); if (ret) return 0; @@ -660,7 +660,7 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct) struct lsmblob blob; struct lsmcontext context; - ret = security_secid_to_secctx(&blob, &context); + ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY); if (ret) return 0; diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c index c6112960fc73..2cb3a8df7932 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -177,7 +177,7 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct) struct lsmcontext context; lsmblob_init(&blob, ct->secmark); - ret = security_secid_to_secctx(&blob, &context); + ret = security_secid_to_secctx(&blob, &context, LSMBLOB_DISPLAY); if (ret) return; diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 0d8b83d84422..f2dffeed4789 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -316,7 +316,7 @@ static void nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context) * blob. security_secid_to_secctx() will know which security * module to use to create the secctx. */ lsmblob_init(&blob, skb->secmark); - security_secid_to_secctx(&blob, context); + security_secid_to_secctx(&blob, context, LSMBLOB_DISPLAY); } read_unlock_bh(&skb->sk->sk_callback_lock); diff --git a/net/netlabel/netlabel_domainhash.c b/net/netlabel/netlabel_domainhash.c index dc8c39f51f7d..2690a528d262 100644 --- a/net/netlabel/netlabel_domainhash.c +++ b/net/netlabel/netlabel_domainhash.c @@ -259,7 +259,7 @@ static void netlbl_domhsh_audit_add(struct netlbl_dom_map *entry, break; } audit_log_format(audit_buf, " res=%u", result == 0 ? 1 : 0); - audit_log_end(audit_buf); + audit_log_end_local(audit_buf, audit_info->localcontext); } } @@ -614,7 +614,7 @@ int netlbl_domhsh_remove_entry(struct netlbl_dom_map *entry, audit_log_format(audit_buf, " nlbl_domain=%s res=1", entry->domain ? entry->domain : "(default)"); - audit_log_end(audit_buf); + audit_log_end_local(audit_buf, audit_info->localcontext); } switch (entry->def.type) { diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c index 3befe0738d31..ff5901113a27 100644 --- a/net/netlabel/netlabel_unlabeled.c +++ b/net/netlabel/netlabel_unlabeled.c @@ -437,13 +437,14 @@ int netlbl_unlhsh_add(struct net *net, unlhsh_add_return: rcu_read_unlock(); if (audit_buf != NULL) { - if (security_secid_to_secctx(lsmblob, &context) == 0) { + if (security_secid_to_secctx(lsmblob, &context, + LSMBLOB_FIRST) == 0) { audit_log_format(audit_buf, " sec_obj=%s", context.context); security_release_secctx(&context); } audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0); - audit_log_end(audit_buf); + audit_log_end_local(audit_buf, audit_info->localcontext); } return ret_val; } @@ -492,13 +493,14 @@ static int netlbl_unlhsh_remove_addr4(struct net *net, if (dev != NULL) dev_put(dev); if (entry != NULL && - security_secid_to_secctx(&entry->lsmblob, &context) == 0) { + security_secid_to_secctx(&entry->lsmblob, &context, + LSMBLOB_FIRST) == 0) { audit_log_format(audit_buf, " sec_obj=%s", context.context); security_release_secctx(&context); } audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0); - audit_log_end(audit_buf); + audit_log_end_local(audit_buf, audit_info->localcontext); } if (entry == NULL) @@ -552,13 +554,14 @@ static int netlbl_unlhsh_remove_addr6(struct net *net, if (dev != NULL) dev_put(dev); if (entry != NULL && - security_secid_to_secctx(&entry->lsmblob, &context) == 0) { + security_secid_to_secctx(&entry->lsmblob, &context, + LSMBLOB_FIRST) == 0) { audit_log_format(audit_buf, " sec_obj=%s", context.context); security_release_secctx(&context); } audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0); - audit_log_end(audit_buf); + audit_log_end_local(audit_buf, audit_info->localcontext); } if (entry == NULL) @@ -741,7 +744,7 @@ static void netlbl_unlabel_acceptflg_set(u8 value, if (audit_buf != NULL) { audit_log_format(audit_buf, " unlbl_accept=%u old=%u", value, old_val); - audit_log_end(audit_buf); + audit_log_end_local(audit_buf, audit_info->localcontext); } } @@ -1122,7 +1125,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd, lsmb = (struct lsmblob *)&addr6->lsmblob; } - ret_val = security_secid_to_secctx(lsmb, &context); + ret_val = security_secid_to_secctx(lsmb, &context, LSMBLOB_FIRST); if (ret_val != 0) goto list_cb_failure; ret_val = nla_put(cb_arg->skb, @@ -1528,14 +1531,11 @@ int __init netlbl_unlabel_defconf(void) int ret_val; struct netlbl_dom_map *entry; struct netlbl_audit audit_info; - struct lsmblob blob; /* Only the kernel is allowed to call this function and the only time * it is called is at bootup before the audit subsystem is reporting * messages so don't worry to much about these values. */ - security_task_getsecid(current, &blob); - /* scaffolding until audit_info.secid is converted */ - audit_info.secid = blob.secid[0]; + security_task_getsecid(current, &audit_info.lsmdata); audit_info.loginuid = GLOBAL_ROOT_UID; audit_info.sessionid = 0; diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c index 951ba0639d20..90a18b245380 100644 --- a/net/netlabel/netlabel_user.c +++ b/net/netlabel/netlabel_user.c @@ -83,14 +83,17 @@ int __init netlbl_netlink_init(void) struct audit_buffer *netlbl_audit_start_common(int type, struct netlbl_audit *audit_info) { + struct audit_context *audit_ctx; struct audit_buffer *audit_buf; struct lsmcontext context; - struct lsmblob blob; if (audit_enabled == AUDIT_OFF) return NULL; - audit_buf = audit_log_start(audit_context(), GFP_ATOMIC, type); + audit_ctx = audit_alloc_for_lsm(GFP_ATOMIC); + audit_info->localcontext = audit_ctx; + + audit_buf = audit_log_start(audit_ctx, GFP_ATOMIC, type); if (audit_buf == NULL) return NULL; @@ -98,11 +101,14 @@ struct audit_buffer *netlbl_audit_start_common(int type, from_kuid(&init_user_ns, audit_info->loginuid), audit_info->sessionid); - lsmblob_init(&blob, audit_info->secid); - if (audit_info->secid != 0 && - security_secid_to_secctx(&blob, &context) == 0) { - audit_log_format(audit_buf, " subj=%s", context.context); - security_release_secctx(&context); + if (lsmblob_is_set(&audit_info->lsmdata)) { + if (!lsm_multiple_contexts() && + security_secid_to_secctx(&audit_info->lsmdata, &context, + LSMBLOB_FIRST) == 0) { + audit_log_format(audit_buf, " subj=%s", + context.context); + security_release_secctx(&context); + } } return audit_buf; diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h index 438b5db6c714..bd4335443b87 100644 --- a/net/netlabel/netlabel_user.h +++ b/net/netlabel/netlabel_user.h @@ -34,11 +34,7 @@ static inline void netlbl_netlink_auditinfo(struct sk_buff *skb, struct netlbl_audit *audit_info) { - struct lsmblob blob; - - security_task_getsecid(current, &blob); - /* scaffolding until secid is converted */ - audit_info->secid = blob.secid[0]; + security_task_getsecid(current, &audit_info->lsmdata); audit_info->loginuid = audit_get_loginuid(current); audit_info->sessionid = audit_get_sessionid(current); } diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index d622c2548d22..6aa4bcc08848 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -4205,30 +4205,32 @@ static void xfrm_audit_common_policyinfo(struct xfrm_policy *xp, void xfrm_audit_policy_add(struct xfrm_policy *xp, int result, bool task_valid) { + struct audit_context *context; struct audit_buffer *audit_buf; - audit_buf = xfrm_audit_start("SPD-add"); + audit_buf = xfrm_audit_start("SPD-add", &context); if (audit_buf == NULL) return; xfrm_audit_helper_usrinfo(task_valid, audit_buf); audit_log_format(audit_buf, " res=%u", result); xfrm_audit_common_policyinfo(xp, audit_buf); - audit_log_end(audit_buf); + audit_log_end_local(audit_buf, context); } EXPORT_SYMBOL_GPL(xfrm_audit_policy_add); void xfrm_audit_policy_delete(struct xfrm_policy *xp, int result, bool task_valid) { + struct audit_context *context; struct audit_buffer *audit_buf; - audit_buf = xfrm_audit_start("SPD-delete"); + audit_buf = xfrm_audit_start("SPD-delete", &context); if (audit_buf == NULL) return; xfrm_audit_helper_usrinfo(task_valid, audit_buf); audit_log_format(audit_buf, " res=%u", result); xfrm_audit_common_policyinfo(xp, audit_buf); - audit_log_end(audit_buf); + audit_log_end_local(audit_buf, context); } EXPORT_SYMBOL_GPL(xfrm_audit_policy_delete); #endif diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index d01ca1a18418..a3d49a854ed2 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -2746,29 +2746,31 @@ static void xfrm_audit_helper_pktinfo(struct sk_buff *skb, u16 family, void xfrm_audit_state_add(struct xfrm_state *x, int result, bool task_valid) { + struct audit_context *context; struct audit_buffer *audit_buf; - audit_buf = xfrm_audit_start("SAD-add"); + audit_buf = xfrm_audit_start("SAD-add", &context); if (audit_buf == NULL) return; xfrm_audit_helper_usrinfo(task_valid, audit_buf); xfrm_audit_helper_sainfo(x, audit_buf); audit_log_format(audit_buf, " res=%u", result); - audit_log_end(audit_buf); + audit_log_end_local(audit_buf, context); } EXPORT_SYMBOL_GPL(xfrm_audit_state_add); void xfrm_audit_state_delete(struct xfrm_state *x, int result, bool task_valid) { + struct audit_context *context; struct audit_buffer *audit_buf; - audit_buf = xfrm_audit_start("SAD-delete"); + audit_buf = xfrm_audit_start("SAD-delete", &context); if (audit_buf == NULL) return; xfrm_audit_helper_usrinfo(task_valid, audit_buf); xfrm_audit_helper_sainfo(x, audit_buf); audit_log_format(audit_buf, " res=%u", result); - audit_log_end(audit_buf); + audit_log_end_local(audit_buf, context); } EXPORT_SYMBOL_GPL(xfrm_audit_state_delete); @@ -2778,7 +2780,7 @@ void xfrm_audit_state_replay_overflow(struct xfrm_state *x, struct audit_buffer *audit_buf; u32 spi; - audit_buf = xfrm_audit_start("SA-replay-overflow"); + audit_buf = xfrm_audit_start("SA-replay-overflow", NULL); if (audit_buf == NULL) return; xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf); @@ -2796,7 +2798,7 @@ void xfrm_audit_state_replay(struct xfrm_state *x, struct audit_buffer *audit_buf; u32 spi; - audit_buf = xfrm_audit_start("SA-replayed-pkt"); + audit_buf = xfrm_audit_start("SA-replayed-pkt", NULL); if (audit_buf == NULL) return; xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf); @@ -2811,7 +2813,7 @@ void xfrm_audit_state_notfound_simple(struct sk_buff *skb, u16 family) { struct audit_buffer *audit_buf; - audit_buf = xfrm_audit_start("SA-notfound"); + audit_buf = xfrm_audit_start("SA-notfound", NULL); if (audit_buf == NULL) return; xfrm_audit_helper_pktinfo(skb, family, audit_buf); @@ -2825,7 +2827,7 @@ void xfrm_audit_state_notfound(struct sk_buff *skb, u16 family, struct audit_buffer *audit_buf; u32 spi; - audit_buf = xfrm_audit_start("SA-notfound"); + audit_buf = xfrm_audit_start("SA-notfound", NULL); if (audit_buf == NULL) return; xfrm_audit_helper_pktinfo(skb, family, audit_buf); @@ -2843,7 +2845,7 @@ void xfrm_audit_state_icvfail(struct xfrm_state *x, __be32 net_spi; __be32 net_seq; - audit_buf = xfrm_audit_start("SA-icv-failure"); + audit_buf = xfrm_audit_start("SA-icv-failure", NULL); if (audit_buf == NULL) return; xfrm_audit_helper_pktinfo(skb, x->props.family, audit_buf); diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index e83fa1c32843..8b6f8402703d 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -340,6 +340,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint, void ima_audit_measurement(struct integrity_iint_cache *iint, const unsigned char *filename) { + struct audit_context *context; struct audit_buffer *ab; char *hash; const char *algo_name = hash_algo_name[iint->ima_hash->algo]; @@ -356,8 +357,8 @@ void ima_audit_measurement(struct integrity_iint_cache *iint, hex_byte_pack(hash + (i * 2), iint->ima_hash->digest[i]); hash[i * 2] = '\0'; - ab = audit_log_start(audit_context(), GFP_KERNEL, - AUDIT_INTEGRITY_RULE); + context = audit_alloc_for_lsm(GFP_KERNEL); + ab = audit_log_start(context, GFP_KERNEL, AUDIT_INTEGRITY_RULE); if (!ab) goto out; @@ -366,7 +367,7 @@ void ima_audit_measurement(struct integrity_iint_cache *iint, audit_log_format(ab, " hash=\"%s:%s\"", algo_name, hash); audit_log_task_info(ab); - audit_log_end(ab); + audit_log_end_local(ab, context); iint->flags |= IMA_AUDITED; out: diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c index 29220056207f..b38163c43659 100644 --- a/security/integrity/integrity_audit.c +++ b/security/integrity/integrity_audit.c @@ -38,13 +38,15 @@ void integrity_audit_message(int audit_msgno, struct inode *inode, const char *cause, int result, int audit_info, int errno) { + struct audit_context *context; struct audit_buffer *ab; char name[TASK_COMM_LEN]; if (!integrity_audit_info && audit_info == 1) /* Skip info messages */ return; - ab = audit_log_start(audit_context(), GFP_KERNEL, audit_msgno); + context = audit_alloc_for_lsm(GFP_KERNEL); + ab = audit_log_start(context, GFP_KERNEL, audit_msgno); audit_log_format(ab, "pid=%d uid=%u auid=%u ses=%u", task_pid_nr(current), from_kuid(&init_user_ns, current_uid()), @@ -63,5 +65,5 @@ void integrity_audit_message(int audit_msgno, struct inode *inode, audit_log_format(ab, " ino=%lu", inode->i_ino); } audit_log_format(ab, " res=%d errno=%d", !result, errno); - audit_log_end(ab); + audit_log_end_local(ab, context); } diff --git a/security/security.c b/security/security.c index 03fb8a702f64..9bb1fe69d310 100644 --- a/security/security.c +++ b/security/security.c @@ -2236,7 +2236,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value, hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) { rc = hp->hook.setprocattr(name, value, size); - if (rc < 0) + if (rc < 0 && rc != -EINVAL) return rc; } @@ -2281,13 +2281,31 @@ int security_ismaclabel(const char *name) } EXPORT_SYMBOL(security_ismaclabel); -int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp) +int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp, + int ilsm) { struct security_hook_list *hp; - int ilsm = lsm_task_ilsm(current); memset(cp, 0, sizeof(*cp)); + /* + * ilsm either is the slot number use for formatting + * or an instruction on which relative slot to use. + */ + if (ilsm == LSMBLOB_DISPLAY) + ilsm = lsm_task_ilsm(current); + else if (ilsm == LSMBLOB_FIRST) + ilsm = LSMBLOB_INVALID; + else if (ilsm < 0) { + WARN_ONCE(true, + "LSM: %s unknown interface LSM\n", __func__); + ilsm = LSMBLOB_INVALID; + } else if (ilsm >= lsm_slot) { + WARN_ONCE(true, + "LSM: %s invalid interface LSM\n", __func__); + ilsm = LSMBLOB_INVALID; + } + hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) { if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) continue; @@ -2317,7 +2335,7 @@ int security_secctx_to_secid(const char *secdata, u32 seclen, return hp->hook.secctx_to_secid(secdata, seclen, &blob->secid[hp->lsmid->slot]); } - return 0; + return -EOPNOTSUPP; } EXPORT_SYMBOL(security_secctx_to_secid); @@ -2811,23 +2829,17 @@ int security_key_getsecurity(struct key *key, char **_buffer) int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule) { struct security_hook_list *hp; - bool one_is_good = false; - int rc = 0; - int trc; + int ilsm = lsm_task_ilsm(current); hlist_for_each_entry(hp, &security_hook_heads.audit_rule_init, list) { if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) continue; - trc = hp->hook.audit_rule_init(field, op, rulestr, - &lsmrule[hp->lsmid->slot]); - if (trc == 0) - one_is_good = true; - else - rc = trc; + if (ilsm != LSMBLOB_INVALID && ilsm != hp->lsmid->slot) + continue; + return hp->hook.audit_rule_init(field, op, rulestr, + &lsmrule[hp->lsmid->slot]); } - if (one_is_good) - return 0; - return rc; + return 0; } int security_audit_rule_known(struct audit_krule *krule) @@ -2859,6 +2871,8 @@ int security_audit_rule_match(struct lsmblob *blob, u32 field, u32 op, continue; if (lsmrule[hp->lsmid->slot] == NULL) continue; + if (lsmrule[hp->lsmid->slot] == NULL) + continue; rc = hp->hook.audit_rule_match(blob->secid[hp->lsmid->slot], field, op, &lsmrule[hp->lsmid->slot]); diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index ad946ccf5023..cefdc531ebdc 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -185,7 +185,8 @@ static void smk_netlabel_audit_set(struct netlbl_audit *nap) nap->loginuid = audit_get_loginuid(current); nap->sessionid = audit_get_sessionid(current); - nap->secid = skp->smk_secid; + lsmblob_init(&nap->lsmdata, 0); + nap->lsmdata.secid[smack_lsmid.slot] = skp->smk_secid; } /* -- 2.25.4

Add an entry /proc/.../attr/context which displays the full process security "context" in compound format: lsm1\0value\0lsm2\0value\0... This entry is not writable. A security module may decide that its policy does not allow this information to be displayed. In this case none of the information will be displayed. Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; Cc: linux-api(a)vger.kernel.org Cc: linux-doc(a)vger.kernel.org --- Documentation/ABI/testing/procfs-attr-context | 14 ++++ Documentation/security/lsm.rst | 14 ++++ fs/proc/base.c | 1 + include/linux/lsm_hooks.h | 6 ++ security/apparmor/include/procattr.h | 2 +- security/apparmor/lsm.c | 8 +- security/apparmor/procattr.c | 22 +++--- security/security.c | 79 +++++++++++++++++++ security/selinux/hooks.c | 2 +- security/smack/smack_lsm.c | 2 +- 10 files changed, 135 insertions(+), 15 deletions(-) create mode 100644 Documentation/ABI/testing/procfs-attr-context diff --git a/Documentation/ABI/testing/procfs-attr-context b/Documentation/ABI/testing/procfs-attr-context new file mode 100644 index 000000000000..40da1c397c30 --- /dev/null +++ b/Documentation/ABI/testing/procfs-attr-context @@ -0,0 +1,14 @@ +What: /proc/*/attr/context +Contact: linux-security-module(a)vger.kernel.org, +Description: The current security information used by all Linux + security module (LSMs) that are active on the system. + The details of permissions required to read from + this interface and hence obtain the security state + of the task identified is dependent on the LSMs that + are active on the system. + A process cannot write to this interface. + The data provided by this interface will have the form: + lsm_name\0lsm_data\0[lsm_name\0lsm_data\0]... + where lsm_name is the name of the LSM and the following + lsm_data is the process data for that LSM. +Users: LSM user-space diff --git a/Documentation/security/lsm.rst b/Documentation/security/lsm.rst index b77b4a540391..070225ae6ceb 100644 --- a/Documentation/security/lsm.rst +++ b/Documentation/security/lsm.rst @@ -143,3 +143,17 @@ separated list of the active security modules. The file ``/proc/pid/attr/interface_lsm`` contains the name of the security module for which the ``/proc/pid/attr/current`` interface will apply. This interface can be written to. + +The infrastructure does provide an interface for the special +case where multiple security modules provide a process context. +This is provided in compound context format. + +- `lsm\0value\0lsm\0value\0` + +The `lsm` and `value` fields are NUL-terminated bytestrings. +Each field may contain whitespace or non-printable characters. +The NUL bytes are included in the size of a compound context. +The context ``Bell\0Secret\0Biba\0Loose\0`` has a size of 23. + +The file ``/proc/pid/attr/context`` provides the security +context of the identified process. diff --git a/fs/proc/base.c b/fs/proc/base.c index 158771f87e94..bf23e2bb240a 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2809,6 +2809,7 @@ static const struct pid_entry attr_dir_stuff[] = { ATTR(NULL, "keycreate", 0666), ATTR(NULL, "sockcreate", 0666), ATTR(NULL, "interface_lsm", 0666), + ATTR(NULL, "context", 0444), #ifdef CONFIG_SECURITY_SMACK DIR("smack", 0555, proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops), diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 28a036374834..5e7b2c3ab133 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1372,6 +1372,12 @@ * @pages contains the number of pages. * Return 0 if permission is granted. * + * @getprocattr: + * Provide the named process attribute for display in special files in + * the /proc/.../attr directory. Attribute naming and the data displayed + * is at the discretion of the security modules. The exception is the + * "context" attribute, which will contain the security context of the + * task as a nul terminated text string without trailing whitespace. * @ismaclabel: * Check if the extended attribute specified by @name * represents a MAC label. Returns 1 if name is a MAC diff --git a/security/apparmor/include/procattr.h b/security/apparmor/include/procattr.h index 31689437e0e1..03dbfdb2f2c0 100644 --- a/security/apparmor/include/procattr.h +++ b/security/apparmor/include/procattr.h @@ -11,7 +11,7 @@ #ifndef __AA_PROCATTR_H #define __AA_PROCATTR_H -int aa_getprocattr(struct aa_label *label, char **string); +int aa_getprocattr(struct aa_label *label, char **string, bool newline); int aa_setprocattr_changehat(char *args, size_t size, int flags); #endif /* __AA_PROCATTR_H */ diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index bfcb78149e9c..4af0518b55d6 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -593,6 +593,7 @@ static int apparmor_getprocattr(struct task_struct *task, char *name, const struct cred *cred = get_task_cred(task); struct aa_task_ctx *ctx = task_ctx(current); struct aa_label *label = NULL; + bool newline = true; if (strcmp(name, "current") == 0) label = aa_get_newest_label(cred_label(cred)); @@ -600,11 +601,14 @@ static int apparmor_getprocattr(struct task_struct *task, char *name, label = aa_get_newest_label(ctx->previous); else if (strcmp(name, "exec") == 0 && ctx->onexec) label = aa_get_newest_label(ctx->onexec); - else + else if (strcmp(name, "context") == 0) { + label = aa_get_newest_label(cred_label(cred)); + newline = false; + } else error = -EINVAL; if (label) - error = aa_getprocattr(label, value); + error = aa_getprocattr(label, value, newline); aa_put_label(label); put_cred(cred); diff --git a/security/apparmor/procattr.c b/security/apparmor/procattr.c index c929bf4a3df1..be3b083d9b74 100644 --- a/security/apparmor/procattr.c +++ b/security/apparmor/procattr.c @@ -20,6 +20,7 @@ * aa_getprocattr - Return the profile information for @profile * @profile: the profile to print profile info about (NOT NULL) * @string: Returns - string containing the profile info (NOT NULL) + * @newline: Should a newline be added to @string. * * Returns: length of @string on success else error on failure * @@ -30,20 +31,21 @@ * * Returns: size of string placed in @string else error code on failure */ -int aa_getprocattr(struct aa_label *label, char **string) +int aa_getprocattr(struct aa_label *label, char **string, bool newline) { struct aa_ns *ns = labels_ns(label); struct aa_ns *current_ns = aa_get_current_ns(); + int flags = FLAG_VIEW_SUBNS | FLAG_HIDDEN_UNCONFINED; int len; if (!aa_ns_visible(current_ns, ns, true)) { aa_put_ns(current_ns); return -EACCES; } + if (newline) + flags |= FLAG_SHOW_MODE; - len = aa_label_snxprint(NULL, 0, current_ns, label, - FLAG_SHOW_MODE | FLAG_VIEW_SUBNS | - FLAG_HIDDEN_UNCONFINED); + len = aa_label_snxprint(NULL, 0, current_ns, label, flags); AA_BUG(len < 0); *string = kmalloc(len + 2, GFP_KERNEL); @@ -52,19 +54,19 @@ int aa_getprocattr(struct aa_label *label, char **string) return -ENOMEM; } - len = aa_label_snxprint(*string, len + 2, current_ns, label, - FLAG_SHOW_MODE | FLAG_VIEW_SUBNS | - FLAG_HIDDEN_UNCONFINED); + len = aa_label_snxprint(*string, len + 2, current_ns, label, flags); if (len < 0) { aa_put_ns(current_ns); return len; } - (*string)[len] = '\n'; - (*string)[len + 1] = 0; + if (newline) { + (*string)[len] = '\n'; + (*string)[++len] = 0; + } aa_put_ns(current_ns); - return len + 1; + return len; } /** diff --git a/security/security.c b/security/security.c index 9bb1fe69d310..50cf7c58fbbf 100644 --- a/security/security.c +++ b/security/security.c @@ -776,6 +776,57 @@ static void __init lsm_early_task(struct task_struct *task) panic("%s: Early task alloc failed.\n", __func__); } +/** + * append_ctx - append a lsm/context pair to a compound context + * @ctx: the existing compound context + * @ctxlen: size of the old context, including terminating nul byte + * @lsm: new lsm name, nul terminated + * @new: new context, possibly nul terminated + * @newlen: maximum size of @new + * + * replace @ctx with a new compound context, appending @newlsm and @new + * to @ctx. On exit the new data replaces the old, which is freed. + * @ctxlen is set to the new size, which includes a trailing nul byte. + * + * Returns 0 on success, -ENOMEM if no memory is available. + */ +static int append_ctx(char **ctx, int *ctxlen, const char *lsm, char *new, + int newlen) +{ + char *final; + size_t llen; + size_t nlen; + size_t flen; + + llen = strlen(lsm) + 1; + /* + * A security module may or may not provide a trailing nul on + * when returning a security context. There is no definition + * of which it should be, and there are modules that do it + * each way. + */ + nlen = strnlen(new, newlen); + + flen = *ctxlen + llen + nlen + 1; + final = kzalloc(flen, GFP_KERNEL); + + if (final == NULL) + return -ENOMEM; + + if (*ctxlen) + memcpy(final, *ctx, *ctxlen); + + memcpy(final + *ctxlen, lsm, llen); + memcpy(final + *ctxlen + llen, new, nlen); + + kfree(*ctx); + + *ctx = final; + *ctxlen = flen; + + return 0; +} + /* * The default value of the LSM hook is defined in linux/lsm_hook_defs.h and * can be accessed with: @@ -2161,6 +2212,10 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name, char **value) { struct security_hook_list *hp; + char *final = NULL; + char *cp; + int rc = 0; + int finallen = 0; int ilsm = lsm_task_ilsm(current); int slot = 0; @@ -2188,6 +2243,30 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name, return -ENOMEM; } + if (!strcmp(name, "context")) { + hlist_for_each_entry(hp, &security_hook_heads.getprocattr, + list) { + rc = hp->hook.getprocattr(p, "context", &cp); + if (rc == -EINVAL) + continue; + if (rc < 0) { + kfree(final); + return rc; + } + rc = append_ctx(&final, &finallen, hp->lsmid->lsm, + cp, rc); + kfree(cp); + if (rc < 0) { + kfree(final); + return rc; + } + } + if (final == NULL) + return -EINVAL; + *value = final; + return finallen; + } + hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) { if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm)) continue; diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 60e35d31cc4c..05a98dcf377c 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -6300,7 +6300,7 @@ static int selinux_getprocattr(struct task_struct *p, goto bad; } - if (!strcmp(name, "current")) + if (!strcmp(name, "current") || !strcmp(name, "context")) sid = __tsec->sid; else if (!strcmp(name, "prev")) sid = __tsec->osid; diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 03a1c40174d7..363c2cb76936 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -3478,7 +3478,7 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value) char *cp; int slen; - if (strcmp(name, "current") != 0) + if (strcmp(name, "current") != 0 && strcmp(name, "context") != 0) return -EINVAL; cp = kstrdup(skp->smk_known, GFP_KERNEL); -- 2.25.4