From 0ffbc876d03c80b83d70aeefac7bbb94a9f4e135 Mon Sep 17 00:00:00 2001 From: Casey Schaufler Date: Sat, 16 Aug 2025 10:28:59 -0700 Subject: audit: add record for multiple object contexts Create a new audit record AUDIT_MAC_OBJ_CONTEXTS. An example of the MAC_OBJ_CONTEXTS record is: type=MAC_OBJ_CONTEXTS 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 [PM: subj tweak, audit example readability indents] Signed-off-by: Paul Moore --- kernel/audit.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 57 insertions(+), 1 deletion(-) (limited to 'kernel/audit.c') diff --git a/kernel/audit.c b/kernel/audit.c index c924b30f2524..bd7474fd8d2c 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -85,7 +85,9 @@ static unsigned int audit_net_id; /* Number of modules that provide a security context. List of lsms that provide a security context */ static u32 audit_subj_secctx_cnt; +static u32 audit_obj_secctx_cnt; static const struct lsm_id *audit_subj_lsms[MAX_LSM_COUNT]; +static const struct lsm_id *audit_obj_lsms[MAX_LSM_COUNT]; /** * struct audit_net - audit private network namespace data @@ -305,6 +307,12 @@ void audit_cfg_lsm(const struct lsm_id *lsmid, int flags) return; audit_subj_lsms[audit_subj_secctx_cnt++] = lsmid; } + if (flags & AUDIT_CFG_LSM_SECCTX_OBJECT) { + for (i = 0 ; i < audit_obj_secctx_cnt; i++) + if (audit_obj_lsms[i] == lsmid) + return; + audit_obj_lsms[audit_obj_secctx_cnt++] = lsmid; + } } /** @@ -1142,7 +1150,6 @@ static int is_audit_feature_set(int i) return af.features & AUDIT_FEATURE_TO_MASK(i); } - static int audit_get_feature(struct sk_buff *skb) { u32 seq; @@ -2337,6 +2344,55 @@ int audit_log_task_context(struct audit_buffer *ab) } EXPORT_SYMBOL(audit_log_task_context); +int audit_log_obj_ctx(struct audit_buffer *ab, struct lsm_prop *prop) +{ + int i; + int rc; + int error = 0; + char *space = ""; + struct lsm_context ctx; + + if (audit_obj_secctx_cnt < 2) { + error = security_lsmprop_to_secctx(prop, &ctx, LSM_ID_UNDEF); + if (error < 0) { + if (error != -EINVAL) + goto error_path; + return error; + } + audit_log_format(ab, " obj=%s", ctx.context); + security_release_secctx(&ctx); + return 0; + } + audit_log_format(ab, " obj=?"); + error = audit_buffer_aux_new(ab, AUDIT_MAC_OBJ_CONTEXTS); + if (error) + goto error_path; + + for (i = 0; i < audit_obj_secctx_cnt; i++) { + rc = security_lsmprop_to_secctx(prop, &ctx, + audit_obj_lsms[i]->id); + if (rc < 0) { + audit_log_format(ab, "%sobj_%s=?", space, + audit_obj_lsms[i]->name); + if (rc != -EINVAL) + audit_panic("error in audit_log_obj_ctx"); + error = rc; + } else { + audit_log_format(ab, "%sobj_%s=%s", space, + audit_obj_lsms[i]->name, ctx.context); + security_release_secctx(&ctx); + } + space = " "; + } + + audit_buffer_aux_end(ab); + return error; + +error_path: + audit_panic("error in audit_log_obj_ctx"); + return error; +} + void audit_log_d_path_exe(struct audit_buffer *ab, struct mm_struct *mm) { -- cgit v1.2.3