From: Casey Schaufler <casey@schaufler-ca.com>
To: casey.schaufler@intel.com, jmorris@namei.org,
linux-security-module@vger.kernel.org, selinux@vger.kernel.org
Cc: john.johansen@canonical.com, linux-kernel@vger.kernel.org,
linux-audit@redhat.com, sds@tycho.nsa.gov
Subject: [PATCH v29 25/28] Audit: Add record for multiple task security contexts
Date: Fri, 24 Sep 2021 10:54:38 -0700 [thread overview]
Message-ID: <20210924175441.7943-26-casey@schaufler-ca.com> (raw)
In-Reply-To: <20210924175441.7943-1-casey@schaufler-ca.com>
Create a new audit record AUDIT_MAC_TASK_CONTEXTS.
An example of the MAC_TASK_CONTEXTS (1420) record is:
type=UNKNOWN[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=?".
A 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.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
include/linux/security.h | 9 ++++++
include/uapi/linux/audit.h | 1 +
kernel/audit.c | 64 ++++++++++++++++++++++++++++++++------
3 files changed, 65 insertions(+), 9 deletions(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index 7096a60fbbfe..cd67d801e94c 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -230,6 +230,15 @@ static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb)
extern int lsm_name_to_slot(char *name);
extern const char *lsm_slot_to_name(int slot);
+static inline bool lsm_multiple_contexts(void)
+{
+#ifdef CONFIG_SECURITY
+ return lsm_slot_to_name(1) != NULL;
+#else
+ return false;
+#endif
+}
+
/**
* lsmblob_value - find the first non-zero value in an lsmblob structure.
* @blob: Pointer to the data
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index daa481729e9b..6a0ac60688b1 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -139,6 +139,7 @@
#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 0d4aa6667125..707689605791 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -197,6 +197,9 @@ static struct audit_ctl_mutex {
struct audit_context_entry {
struct list_head list;
int type; /* Audit record type */
+ union {
+ struct lsmblob mac_task_context;
+ };
};
/* The audit_buffer is used when formatting an audit record. The caller
@@ -2139,6 +2142,21 @@ void audit_log_key(struct audit_buffer *ab, char *key)
audit_log_format(ab, "(null)");
}
+static int audit_add_aux_task(struct audit_buffer *ab, struct lsmblob *blob)
+{
+ struct audit_context_entry *ace;
+
+ ace = kzalloc(sizeof(*ace), GFP_KERNEL);
+ if (!ace)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&ace->list);
+ ace->type = AUDIT_MAC_TASK_CONTEXTS;
+ ace->mac_task_context = *blob;
+ list_add(&ace->list, &ab->aux_records);
+ return 0;
+}
+
int audit_log_task_context(struct audit_buffer *ab)
{
int error;
@@ -2149,16 +2167,22 @@ int audit_log_task_context(struct audit_buffer *ab)
if (!lsmblob_is_set(&blob))
return 0;
- error = security_secid_to_secctx(&blob, &context, LSMBLOB_FIRST);
- if (error) {
- if (error != -EINVAL)
- goto error_path;
+ if (!lsm_multiple_contexts()) {
+ error = security_secid_to_secctx(&blob, &context,
+ LSMBLOB_FIRST);
+ if (error) {
+ if (error != -EINVAL)
+ goto error_path;
+ return 0;
+ }
+ audit_log_format(ab, " subj=%s", context.context);
+ security_release_secctx(&context);
return 0;
}
-
- audit_log_format(ab, " subj=%s", context.context);
- security_release_secctx(&context);
- return 0;
+ audit_log_format(ab, " subj=?");
+ error = audit_add_aux_task(ab, &blob);
+ if (!error)
+ return 0;
error_path:
audit_panic("error in audit_log_task_context");
@@ -2419,9 +2443,12 @@ void audit_log_end(struct audit_buffer *ab)
struct audit_context_entry *entry;
struct audit_context mcontext;
struct audit_context *mctx;
+ struct lsmcontext lcontext;
struct audit_buffer *mab;
struct list_head *l;
struct list_head *n;
+ int rc;
+ int i;
if (!ab)
return;
@@ -2448,7 +2475,26 @@ void audit_log_end(struct audit_buffer *ab)
continue;
}
switch (entry->type) {
- /* Don't know of any quite yet. */
+ case AUDIT_MAC_TASK_CONTEXTS:
+ for (i = 0; i < LSMBLOB_ENTRIES; i++) {
+ if (entry->mac_task_context.secid[i] == 0)
+ continue;
+ rc = security_secid_to_secctx(
+ &entry->mac_task_context,
+ &lcontext, i);
+ if (rc) {
+ if (rc != -EINVAL)
+ audit_panic("error in audit_log_end");
+ audit_log_format(mab, "subj_%s=?",
+ lsm_slot_to_name(0));
+ } else {
+ audit_log_format(mab, "subj_%s=%s",
+ lsm_slot_to_name(0),
+ lcontext.context);
+ security_release_secctx(&lcontext);
+ }
+ }
+ break;
default:
audit_panic("Unknown type in audit_log_end");
break;
--
2.31.1
--
Linux-audit mailing list
Linux-audit@redhat.com
https://listman.redhat.com/mailman/listinfo/linux-audit
next prev parent reply other threads:[~2021-09-24 18:22 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210924175441.7943-1-casey.ref@schaufler-ca.com>
2021-09-24 17:54 ` [PATCH v29 00/28] LSM: Module stacking for AppArmor Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 01/28] LSM: Infrastructure management of the sock security Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 02/28] LSM: Add the lsmblob data structure Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 03/28] LSM: provide lsm name and id slot mappings Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 04/28] IMA: avoid label collisions with stacked LSMs Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 05/28] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 06/28] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 07/28] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 08/28] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 09/28] LSM: Use lsmblob in security_ipc_getsecid Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 10/28] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 11/28] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 12/28] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 13/28] IMA: Change internal interfaces to use lsmblobs Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 14/28] LSM: Specify which LSM to display Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 15/28] LSM: Ensure the correct LSM context releaser Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 16/28] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 17/28] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 18/28] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 19/28] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 20/28] LSM: Verify LSM display sanity in binder Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 21/28] LSM: Extend security_secid_to_secctx to include module selection Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 22/28] Audit: Keep multiple LSM data in audit_names Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 23/28] Audit: Create audit_stamp structure Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 24/28] Audit: Add framework for auxiliary records Casey Schaufler
2021-09-24 17:54 ` Casey Schaufler [this message]
2021-09-24 17:54 ` [PATCH v29 26/28] Audit: Add record for multiple object security contexts Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 27/28] LSM: Add /proc attr entry for full LSM context Casey Schaufler
2021-09-24 17:54 ` [PATCH v29 28/28] AppArmor: Remove the exclusive flag Casey Schaufler
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