[PATCH v20 11/23] LSM: Use lsmblob in security_cred_getsecid

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 --- include/linux/security.h | 2 +- kernel/audit.c | 25 +++++++---------------- kernel/audit.h | 5 +++-- kernel/auditsc.c | 33 +++++++++++-------------------- security/integrity/ima/ima_main.c | 8 ++++---- security/security.c | 12 ++++++++--- 6 files changed, 36 insertions(+), 49 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index 63d0c9a6cb42..7de2b4e62f55 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -462,7 +462,7 @@ 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 0f7cadd5221a..88b55b42756e 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. */ kuid_t audit_sig_uid = INVALID_UID; pid_t audit_sig_pid = -1; -u32 audit_sig_sid = 0; +struct lsmblob audit_sig_lsm; /* Records can be lost in several ways: 0) [suppressed in audit_alloc] @@ -1442,29 +1442,21 @@ 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); } @@ -2350,7 +2342,6 @@ 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 || @@ -2361,9 +2352,7 @@ 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 ddc22878433d..ec0cfa7364cc 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; @@ -329,7 +330,7 @@ extern char *audit_unpack_string(void **bufp, size_t *remain, size_t len); extern pid_t audit_sig_pid; extern kuid_t audit_sig_uid; -extern u32 audit_sig_sid; +extern struct lsmblob audit_sig_lsm; extern int audit_filter(int msgtype, unsigned int listtype); diff --git a/kernel/auditsc.c b/kernel/auditsc.c index b58b0048702a..b15222181700 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -113,7 +113,7 @@ 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; @@ -2435,15 +2434,12 @@ 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); } @@ -2459,7 +2455,6 @@ 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; @@ -2471,9 +2466,7 @@ 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; } @@ -2494,9 +2487,7 @@ 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 9ad475f6fca5..97b26c425ac5 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -463,7 +463,6 @@ 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); @@ -473,9 +472,10 @@ 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 d641c6dc5933..c3bac45bbb79 100644 --- a/security/security.c +++ b/security/security.c @@ -1692,10 +1692,16 @@ 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); -- 2.24.1