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From: Casey Schaufler <casey@schaufler-ca.com>
To: casey@schaufler-ca.com, paul@paul-moore.com,
	linux-security-module@vger.kernel.org
Cc: jmorris@namei.org, serge@hallyn.com, keescook@chromium.org,
	john.johansen@canonical.com, penguin-kernel@i-love.sakura.ne.jp,
	stephen.smalley.work@gmail.com, linux-kernel@vger.kernel.org,
	mic@digikod.net
Subject: [PATCH v39 24/42] Audit: Add record for multiple task security contexts
Date: Fri, 15 Dec 2023 14:16:18 -0800	[thread overview]
Message-ID: <20231215221636.105680-25-casey@schaufler-ca.com> (raw)
In-Reply-To: <20231215221636.105680-1-casey@schaufler-ca.com>

Create a new audit record AUDIT_MAC_TASK_CONTEXTS.
An example of the MAC_TASK_CONTEXTS (1420) record is:

    type=MAC_TASK_CONTEXTS[1420]
    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.

Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hooks.h  |  2 ++
 include/linux/security.h   |  1 +
 include/uapi/linux/audit.h |  1 +
 kernel/audit.c             | 45 ++++++++++++++++++++++++++++++++------
 security/apparmor/lsm.c    |  1 +
 security/bpf/hooks.c       |  1 +
 security/security.c        |  3 +++
 security/selinux/hooks.c   |  1 +
 security/smack/smack_lsm.c |  1 +
 9 files changed, 49 insertions(+), 7 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index efd4a0655159..605aaf38c3f5 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -47,12 +47,14 @@ struct security_hook_heads {
  * struct lsm_id - Identify a Linux Security Module.
  * @lsm: name of the LSM, must be approved by the LSM maintainers
  * @id: LSM ID number from uapi/linux/lsm.h
+ * @lsmblob: indicates the LSM has an entry in struct lsmblob
  *
  * Contains the information that identifies the LSM.
  */
 struct lsm_id {
 	const char	*name;
 	u64		id;
+	bool		lsmblob;
 };
 
 /*
diff --git a/include/linux/security.h b/include/linux/security.h
index 360a454d5f8e..947cb3a35db4 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -192,6 +192,7 @@ struct lsmblob {
 
 extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1];
 extern u32 lsm_active_cnt;
+extern u32 lsm_blob_cnt;
 extern const struct lsm_id *lsm_idlist[];
 
 /* These functions are in security/commoncap.c */
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index d676ed2b246e..dc045164b86b 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -143,6 +143,7 @@
 #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 task 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 b194494c4dc4..9d971fa96c0e 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -54,6 +54,7 @@
 #include <net/netlink.h>
 #include <linux/skbuff.h>
 #include <linux/security.h>
+#include <linux/lsm_hooks.h>
 #include <linux/freezer.h>
 #include <linux/pid_namespace.h>
 #include <net/netns/generic.h>
@@ -2228,21 +2229,51 @@ int audit_log_task_context(struct audit_buffer *ab)
 {
 	struct lsmcontext ctx;
 	struct lsmblob blob;
+	bool space = false;
 	int error;
+	int i;
 
 	security_current_getlsmblob_subj(&blob);
 	if (!lsmblob_is_set(&blob))
 		return 0;
 
-	error = security_lsmblob_to_secctx(&blob, &ctx, LSM_ID_UNDEF);
-	if (error < 0) {
-		if (error != -EINVAL)
-			goto error_path;
+	if (lsm_blob_cnt < 2) {
+		error = security_lsmblob_to_secctx(&blob, &ctx, LSM_ID_UNDEF);
+		if (error < 0) {
+			if (error != -EINVAL)
+				goto error_path;
+			return 0;
+		}
+		audit_log_format(ab, " subj=%s", ctx.context);
+		security_release_secctx(&ctx);
 		return 0;
 	}
-
-	audit_log_format(ab, " subj=%s", ctx.context);
-	security_release_secctx(&ctx);
+	/* Multiple LSMs provide contexts. Include an aux record. */
+	audit_log_format(ab, " subj=?");
+	error = audit_buffer_aux_new(ab, AUDIT_MAC_TASK_CONTEXTS);
+	if (error)
+		goto error_path;
+
+	for (i = 0; i < lsm_active_cnt; i++) {
+		if (!lsm_idlist[i]->lsmblob)
+			continue;
+		error = security_lsmblob_to_secctx(&blob, &ctx,
+						   lsm_idlist[i]->id);
+		if (error < 0) {
+			if (error == -EOPNOTSUPP)
+				continue;
+			audit_log_format(ab, "%ssubj_%s=?", space ? " " : "",
+					 lsm_idlist[i]->name);
+			if (error != -EINVAL)
+				audit_panic("error in audit_log_task_context");
+		} else {
+			audit_log_format(ab, "%ssubj_%s=%s", space ? " " : "",
+					 lsm_idlist[i]->name, ctx.context);
+			security_release_secctx(&ctx);
+		}
+		space = true;
+	}
+	audit_buffer_aux_end(ab);
 	return 0;
 
 error_path:
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index b5f3beb26d5a..075942b253ae 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1447,6 +1447,7 @@ struct lsm_blob_sizes apparmor_blob_sizes __ro_after_init = {
 static const struct lsm_id apparmor_lsmid = {
 	.name = "apparmor",
 	.id = LSM_ID_APPARMOR,
+	.lsmblob = true,
 };
 
 static struct security_hook_list apparmor_hooks[] __ro_after_init = {
diff --git a/security/bpf/hooks.c b/security/bpf/hooks.c
index 57b9ffd53c98..2da40774dd20 100644
--- a/security/bpf/hooks.c
+++ b/security/bpf/hooks.c
@@ -19,6 +19,7 @@ static struct security_hook_list bpf_lsm_hooks[] __ro_after_init = {
 static const struct lsm_id bpf_lsmid = {
 	.name = "bpf",
 	.id = LSM_ID_BPF,
+	.lsmblob = true,
 };
 
 static int __init bpf_lsm_init(void)
diff --git a/security/security.c b/security/security.c
index 444051575793..8ff6cef26e6c 100644
--- a/security/security.c
+++ b/security/security.c
@@ -269,6 +269,7 @@ static void __init initialize_lsm(struct lsm_info *lsm)
  * Current index to use while initializing the lsm id list.
  */
 u32 lsm_active_cnt __ro_after_init;
+u32 lsm_blob_cnt __ro_after_init;
 const struct lsm_id *lsm_idlist[LSM_CONFIG_COUNT];
 
 /**
@@ -599,6 +600,8 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
 		if (lsm_active_cnt >= LSM_CONFIG_COUNT)
 			panic("%s Too many LSMs registered.\n", __func__);
 		lsm_idlist[lsm_active_cnt++] = lsmid;
+		if (lsmid->lsmblob)
+			lsm_blob_cnt++;
 	}
 
 	for (i = 0; i < count; i++) {
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index ed4237223959..656f25337334 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -7092,6 +7092,7 @@ static int selinux_uring_cmd(struct io_uring_cmd *ioucmd)
 static const struct lsm_id selinux_lsmid = {
 	.name = "selinux",
 	.id = LSM_ID_SELINUX,
+	.lsmblob = true,
 };
 
 /*
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index a58e2c14f120..a9ab31a40e36 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -5069,6 +5069,7 @@ struct lsm_blob_sizes smack_blob_sizes __ro_after_init = {
 static const struct lsm_id smack_lsmid = {
 	.name = "smack",
 	.id = LSM_ID_SMACK,
+	.lsmblob = true,
 };
 
 static struct security_hook_list smack_hooks[] __ro_after_init = {
-- 
2.41.0


  parent reply	other threads:[~2023-12-15 22:35 UTC|newest]

Thread overview: 72+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20231215221636.105680-1-casey.ref@schaufler-ca.com>
2023-12-15 22:15 ` [PATCH v39 00/42] LSM: General module stacking Casey Schaufler
2023-12-15 22:15   ` [PATCH v39 01/42] integrity: disassociate ima_filter_rule from security_audit_rule Casey Schaufler
2024-03-06  9:54     ` Roberto Sassu
2024-03-06 16:56       ` Casey Schaufler
2024-03-07  7:56         ` Roberto Sassu
2024-06-21 16:50     ` Paul Moore
2024-06-21 19:07       ` Paul Moore
2024-06-21 20:23         ` Mimi Zohar
2024-06-21 20:34           ` Roberto Sassu
2024-06-21 21:19             ` Paul Moore
2024-06-24  8:45               ` Roberto Sassu
2024-06-24 13:57                 ` Mimi Zohar
2024-06-24 22:03                   ` Paul Moore
2024-06-24 22:19                     ` Casey Schaufler
2024-06-24 23:05                       ` Paul Moore
2024-06-24 23:16                         ` Casey Schaufler
2024-06-24 23:06                       ` Mimi Zohar
2024-06-21 21:18           ` Paul Moore
2024-06-24 13:58     ` Mimi Zohar
2023-12-15 22:15   ` [PATCH v39 02/42] SM: Infrastructure management of the sock security Casey Schaufler
2024-06-21 20:31     ` Paul Moore
2024-06-21 22:24       ` Casey Schaufler
2024-06-23 19:57         ` Paul Moore
2024-06-24 22:07       ` Paul Moore
2023-12-15 22:15   ` [PATCH v39 03/42] LSM: Add the lsmblob data structure Casey Schaufler
2023-12-15 22:15   ` [PATCH v39 04/42] IMA: avoid label collisions with stacked LSMs Casey Schaufler
2024-03-06 10:09     ` Roberto Sassu
2024-03-06 17:04       ` Casey Schaufler
2024-03-07  8:15         ` Roberto Sassu
2024-03-07 17:36           ` Casey Schaufler
2023-12-15 22:15   ` [PATCH v39 05/42] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 06/42] LSM: Add lsmblob_to_secctx hook Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 07/42] Audit: maintain an lsmblob in audit_context Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 08/42] LSM: Use lsmblob in security_ipc_getsecid Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 09/42] Audit: Update shutdown LSM data Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 10/42] LSM: Use lsmblob in security_current_getsecid Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 11/42] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 12/42] Audit: use an lsmblob in audit_names Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 13/42] LSM: Create new security_cred_getlsmblob LSM hook Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 14/42] Audit: Change context data from secid to lsmblob Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 15/42] Netlabel: Use lsmblob for audit data Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 16/42] LSM: Ensure the correct LSM context releaser Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 17/42] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 18/42] LSM: Use lsmcontext in security_lsmblob_to_secctx Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 19/42] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 20/42] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
2023-12-18  2:50     ` Xiubo Li
2023-12-18 16:55       ` Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 21/42] LSM: security_lsmblob_to_secctx module selection Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 22/42] Audit: Create audit_stamp structure Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 23/42] Audit: Allow multiple records in an audit_buffer Casey Schaufler
2023-12-15 22:16   ` Casey Schaufler [this message]
2023-12-15 22:16   ` [PATCH v39 25/42] audit: multiple subject lsm values for netlabel Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 26/42] Audit: Add record for multiple object contexts Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 27/42] LSM: Remove unused lsmcontext_init() Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 28/42] LSM: Improve logic in security_getprocattr Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 29/42] LSM: secctx provider check on release Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 30/42] LSM: Single calls in socket_getpeersec hooks Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 31/42] LSM: Exclusive secmark usage Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 32/42] LSM: Identify which LSM handles the context string Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 33/42] AppArmor: Remove the exclusive flag Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 34/42] LSM: Add mount opts blob size tracking Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 35/42] LSM: allocate mnt_opts blobs instead of module specific data Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 36/42] LSM: Infrastructure management of the key security blob Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 37/42] LSM: Infrastructure management of the mnt_opts " Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 38/42] LSM: Correct handling of ENOSYS in inode_setxattr Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 39/42] LSM: Remove lsmblob scaffolding Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 40/42] LSM: Allow reservation of netlabel Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 41/42] LSM: restrict security_cred_getsecid() to a single LSM Casey Schaufler
2023-12-15 22:16   ` [PATCH v39 42/42] Smack: Remove LSM_FLAG_EXCLUSIVE Casey Schaufler
2023-12-18  2:18     ` Leesoo Ahn
2024-02-02  0:24   ` [PATCH v39 00/42] LSM: General module stacking John Johansen

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