[PATCH v34 27/29] Audit: Add record for multiple object contexts

Create a new audit record AUDIT_MAC_OBJ_CONTEXTS. An example of the MAC_OBJ_CONTEXTS (1421) record is: type=MAC_OBJ_CONTEXTS[1421] msg=audit(1601152467.009:1050): obj_selinux=unconfined_u:object_r:user_home_t:s0 When an audit event includes a AUDIT_MAC_OBJ_CONTEXTS record the "obj=" field in other records in the event will be "obj=?". An AUDIT_MAC_OBJ_CONTEXTS record is supplied when the system has multiple security modules that may make access decisions based on an object security context. Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; --- include/linux/audit.h | 5 +++ include/uapi/linux/audit.h | 1 + kernel/audit.c | 47 +++++++++++++++++++++++ kernel/auditsc.c | 79 ++++++++++++-------------------------- 4 files changed, 77 insertions(+), 55 deletions(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index 14849d5f84b4..1b05eb2dbe77 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -191,6 +191,8 @@ extern void audit_log_path_denied(int type, const char *operation); extern void audit_log_lost(const char *message); +extern void audit_log_object_context(struct audit_buffer *ab, + struct lsmblob *blob); extern int audit_log_task_context(struct audit_buffer *ab); extern void audit_log_task_info(struct audit_buffer *ab); @@ -251,6 +253,9 @@ static inline void audit_log_key(struct audit_buffer *ab, char *key) { } static inline void audit_log_path_denied(int type, const char *operation) { } +static inline void audit_log_object_context(struct audit_buffer *ab, + struct lsmblob *blob) +{ } static inline int audit_log_task_context(struct audit_buffer *ab) { return 0; diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h index af0aaccfaf57..d25d76b29e3c 100644 --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -144,6 +144,7 @@ #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 task contexts */ +#define AUDIT_MAC_OBJ_CONTEXTS 1421 /* Multiple LSM objext 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 8ed2d717c217..a8c3ec6ba60b 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -2226,6 +2226,53 @@ static void audit_buffer_aux_end(struct audit_buffer *ab) ab->skb = skb_peek(&ab->skb_list); } +void audit_log_object_context(struct audit_buffer *ab, struct lsmblob *blob) +{ + int i; + int error; + struct lsmcontext context; + + if (!lsm_multiple_contexts()) { + error = security_secid_to_secctx(blob, &context, LSMBLOB_FIRST); + if (error) { + if (error != -EINVAL) + goto error_path; + return; + } + audit_log_format(ab, " obj=%s", context.context); + security_release_secctx(&context); + } else { + audit_log_format(ab, " obj=?"); + error = audit_buffer_aux_new(ab, AUDIT_MAC_OBJ_CONTEXTS); + if (error) + goto error_path; + + for (i = 0; i < LSMBLOB_ENTRIES; i++) { + if (blob->secid[i] == 0) + continue; + error = security_secid_to_secctx(blob, &context, i); + if (error) { + audit_log_format(ab, "%sobj_%s=?", + i ? " " : "", + lsm_slot_to_name(i)); + if (error != -EINVAL) + audit_panic("error in audit_log_object_context"); + } else { + audit_log_format(ab, "%sobj_%s=%s", + i ? " " : "", + lsm_slot_to_name(i), + context.context); + security_release_secctx(&context); + } + } + + audit_buffer_aux_end(ab); + } + return; + +error_path: + audit_panic("error in audit_log_object_context"); +} int audit_log_task_context(struct audit_buffer *ab) { diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 557713954a69..04bf3c04ef3d 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1114,36 +1114,25 @@ static inline void audit_free_context(struct audit_context *context) kfree(context); } -static int audit_log_pid_context(struct audit_context *context, pid_t pid, - kuid_t auid, kuid_t uid, - unsigned int sessionid, - struct lsmblob *blob, char *comm) +static void audit_log_pid_context(struct audit_context *context, pid_t pid, + kuid_t auid, kuid_t uid, + unsigned int sessionid, + struct lsmblob *blob, char *comm) { struct audit_buffer *ab; - struct lsmcontext lsmctx; - int rc = 0; ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID); if (!ab) - return rc; + return; 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 (lsmblob_is_set(blob)) { - if (security_secid_to_secctx(blob, &lsmctx, LSMBLOB_FIRST)) { - audit_log_format(ab, " obj=(none)"); - rc = 1; - } else { - audit_log_format(ab, " obj=%s", lsmctx.context); - security_release_secctx(&lsmctx); - } - } + if (lsmblob_is_set(blob)) + audit_log_object_context(ab, blob); audit_log_format(ab, " ocomm="); audit_log_untrustedstring(ab, comm); audit_log_end(ab); - - return rc; } static void audit_log_execve_info(struct audit_context *context, @@ -1420,18 +1409,10 @@ static void show_special(struct audit_context *context, int *call_panic) from_kgid(&init_user_ns, context->ipc.gid), context->ipc.mode); if (osid) { - struct lsmcontext lsmcxt; struct lsmblob blob; lsmblob_init(&blob, osid); - if (security_secid_to_secctx(&blob, &lsmcxt, - LSMBLOB_FIRST)) { - audit_log_format(ab, " osid=%u", osid); - *call_panic = 1; - } else { - audit_log_format(ab, " obj=%s", lsmcxt.context); - security_release_secctx(&lsmcxt); - } + audit_log_object_context(ab, &blob); } if (context->ipc.has_perm) { audit_log_end(ab); @@ -1588,19 +1569,8 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n, from_kgid(&init_user_ns, n->gid), MAJOR(n->rdev), MINOR(n->rdev)); - if (lsmblob_is_set(&n->lsmblob)) { - struct lsmcontext lsmctx; - - if (security_secid_to_secctx(&n->lsmblob, &lsmctx, - LSMBLOB_FIRST)) { - audit_log_format(ab, " osid=?"); - if (call_panic) - *call_panic = 2; - } else { - audit_log_format(ab, " obj=%s", lsmctx.context); - security_release_secctx(&lsmctx); - } - } + if (lsmblob_is_set(&n->lsmblob)) + audit_log_object_context(ab, &n->lsmblob); /* log the audit_names record type */ switch (n->type) { @@ -1805,21 +1775,20 @@ static void audit_log_exit(void) struct audit_aux_data_pids *axs = (void *)aux; for (i = 0; i < axs->pid_count; i++) - if (audit_log_pid_context(context, axs->target_pid[i], - axs->target_auid[i], - axs->target_uid[i], - axs->target_sessionid[i], - &axs->target_lsm[i], - axs->target_comm[i])) - call_panic = 1; - } - - if (context->target_pid && - audit_log_pid_context(context, context->target_pid, - context->target_auid, context->target_uid, - context->target_sessionid, - &context->target_lsm, context->target_comm)) - call_panic = 1; + audit_log_pid_context(context, axs->target_pid[i], + axs->target_auid[i], + axs->target_uid[i], + axs->target_sessionid[i], + &axs->target_lsm[i], + axs->target_comm[i]); + } + + if (context->target_pid) + audit_log_pid_context(context, context->target_pid, + context->target_auid, context->target_uid, + context->target_sessionid, + &context->target_lsm, + context->target_comm); if (context->pwd.dentry && context->pwd.mnt) { ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD); -- 2.35.1