From a59076f2669ec23a122549e1f4114e8d4255b632 Mon Sep 17 00:00:00 2001 From: Casey Schaufler Date: Sat, 16 Aug 2025 10:28:57 -0700 Subject: lsm: security_lsmblob_to_secctx module selection Add a parameter lsmid to security_lsmblob_to_secctx() to identify which of the security modules that may be active should provide the security context. If the value of lsmid is LSM_ID_UNDEF the first LSM providing a hook is used. security_secid_to_secctx() is unchanged, and will always report the first LSM providing a hook. Signed-off-by: Casey Schaufler [PM: subj tweak] Signed-off-by: Paul Moore --- security/security.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) (limited to 'security') diff --git a/security/security.c b/security/security.c index ad163f06bf7a..dd588f548a2b 100644 --- a/security/security.c +++ b/security/security.c @@ -4342,17 +4342,31 @@ EXPORT_SYMBOL(security_secid_to_secctx); * security_lsmprop_to_secctx() - Convert a lsm_prop to a secctx * @prop: lsm specific information * @cp: the LSM context + * @lsmid: which security module to report * * Convert a @prop entry to security context. If @cp is NULL the * length of the result will be returned. This does mean that the * length could change between calls to check the length and the * next call which actually allocates and returns the @cp. * + * @lsmid identifies which LSM should supply the context. + * A value of LSM_ID_UNDEF indicates that the first LSM suppling + * the hook should be used. This is used in cases where the + * ID of the supplying LSM is unambiguous. + * * Return: Return length of data on success, error on failure. */ -int security_lsmprop_to_secctx(struct lsm_prop *prop, struct lsm_context *cp) +int security_lsmprop_to_secctx(struct lsm_prop *prop, struct lsm_context *cp, + int lsmid) { - return call_int_hook(lsmprop_to_secctx, prop, cp); + struct lsm_static_call *scall; + + lsm_for_each_hook(scall, lsmprop_to_secctx) { + if (lsmid != LSM_ID_UNDEF && lsmid != scall->hl->lsmid->id) + continue; + return scall->hl->hook.lsmprop_to_secctx(prop, cp); + } + return LSM_RET_DEFAULT(lsmprop_to_secctx); } EXPORT_SYMBOL(security_lsmprop_to_secctx); -- cgit v1.2.3 From eb59d494eebd4c5414728a35cdea6a0ba78ff26e Mon Sep 17 00:00:00 2001 From: Casey Schaufler Date: Sat, 16 Aug 2025 10:28:58 -0700 Subject: audit: add record for multiple task security contexts Replace the single skb pointer in an audit_buffer with a list of skb pointers. Add the audit_stamp information to the audit_buffer as there's no guarantee that there will be an audit_context containing the stamp associated with the event. At audit_log_end() time create auxiliary records as have been added to the list. Functions are created to manage the skb list in the audit_buffer. Create a new audit record AUDIT_MAC_TASK_CONTEXTS. An example of the MAC_TASK_CONTEXTS record is: type=MAC_TASK_CONTEXTS msg=audit(1600880931.832:113) subj_apparmor=unconfined subj_smack=_ When an audit event includes a AUDIT_MAC_TASK_CONTEXTS record the "subj=" field in other records in the event will be "subj=?". An AUDIT_MAC_TASK_CONTEXTS record is supplied when the system has multiple security modules that may make access decisions based on a subject security context. Refactor audit_log_task_context(), creating a new audit_log_subj_ctx(). This is used in netlabel auditing to provide multiple subject security contexts as necessary. Suggested-by: Paul Moore Signed-off-by: Casey Schaufler [PM: subj tweak, audit example readability indents] Signed-off-by: Paul Moore --- security/apparmor/lsm.c | 3 +++ security/selinux/hooks.c | 3 +++ security/smack/smack_lsm.c | 3 +++ 3 files changed, 9 insertions(+) (limited to 'security') diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 8e1cc229b41b..220d1684b8d4 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -2530,6 +2530,9 @@ static int __init apparmor_init(void) security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks), &apparmor_lsmid); + /* Inform the audit system that secctx is used */ + audit_cfg_lsm(&apparmor_lsmid, AUDIT_CFG_LSM_SECCTX_SUBJECT); + /* Report that AppArmor successfully initialized */ apparmor_initialized = 1; if (aa_g_profile_mode == APPARMOR_COMPLAIN) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index c95a5874bf7d..975b84b466b4 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -7618,6 +7618,9 @@ static __init int selinux_init(void) /* Set the security state for the initial task. */ cred_init_security(); + /* Inform the audit system that secctx is used */ + audit_cfg_lsm(&selinux_lsmid, AUDIT_CFG_LSM_SECCTX_SUBJECT); + default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC); if (!default_noexec) pr_notice("SELinux: virtual memory is executable by default\n"); diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index fc340a6f0dde..eaff9b8901a7 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -5267,6 +5267,9 @@ static __init int smack_init(void) /* initialize the smack_known_list */ init_smack_known_list(); + /* Inform the audit system that secctx is used */ + audit_cfg_lsm(&smack_lsmid, AUDIT_CFG_LSM_SECCTX_SUBJECT); + return 0; } -- cgit v1.2.3 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 --- security/selinux/hooks.c | 4 +++- security/smack/smack_lsm.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) (limited to 'security') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 975b84b466b4..3999f58a1842 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -7619,7 +7619,9 @@ static __init int selinux_init(void) cred_init_security(); /* Inform the audit system that secctx is used */ - audit_cfg_lsm(&selinux_lsmid, AUDIT_CFG_LSM_SECCTX_SUBJECT); + audit_cfg_lsm(&selinux_lsmid, + AUDIT_CFG_LSM_SECCTX_SUBJECT | + AUDIT_CFG_LSM_SECCTX_OBJECT); default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC); if (!default_noexec) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index eaff9b8901a7..fdf2f193a291 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -5268,7 +5268,9 @@ static __init int smack_init(void) init_smack_known_list(); /* Inform the audit system that secctx is used */ - audit_cfg_lsm(&smack_lsmid, AUDIT_CFG_LSM_SECCTX_SUBJECT); + audit_cfg_lsm(&smack_lsmid, + AUDIT_CFG_LSM_SECCTX_SUBJECT | + AUDIT_CFG_LSM_SECCTX_OBJECT); return 0; } -- cgit v1.2.3