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: casey@schaufler-ca.com, linux-audit@redhat.com,
keescook@chromium.org, john.johansen@canonical.com,
penguin-kernel@i-love.sakura.ne.jp, paul@paul-moore.com,
stephen.smalley.work@gmail.com, linux-kernel@vger.kernel.org
Subject: [PATCH v36 26/33] Audit: Allow multiple records in an audit_buffer
Date: Thu, 9 Jun 2022 16:01:39 -0700 [thread overview]
Message-ID: <20220609230146.319210-27-casey@schaufler-ca.com> (raw)
In-Reply-To: <20220609230146.319210-1-casey@schaufler-ca.com>
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 (none are currently defined) as have been added
to the list. Functions are created to manage the skb list
in the audit_buffer.
Suggested-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
kernel/audit.c | 113 +++++++++++++++++++++++++++++++++++++++----------
1 file changed, 90 insertions(+), 23 deletions(-)
diff --git a/kernel/audit.c b/kernel/audit.c
index 6b6c089512f7..987740374dfa 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -197,8 +197,10 @@ static struct audit_ctl_mutex {
* to place it on a transmit queue. Multiple audit_buffers can be in
* use simultaneously. */
struct audit_buffer {
- struct sk_buff *skb; /* formatted skb ready to send */
+ struct sk_buff *skb; /* the skb for audit_log functions */
+ struct sk_buff_head skb_list; /* formatted skbs, ready to send */
struct audit_context *ctx; /* NULL or associated context */
+ struct audit_stamp stamp; /* audit stamp for these records */
gfp_t gfp_mask;
};
@@ -1765,10 +1767,13 @@ __setup("audit_backlog_limit=", audit_backlog_limit_set);
static void audit_buffer_free(struct audit_buffer *ab)
{
+ struct sk_buff *skb;
+
if (!ab)
return;
- kfree_skb(ab->skb);
+ while ((skb = skb_dequeue(&ab->skb_list)))
+ kfree_skb(skb);
kmem_cache_free(audit_buffer_cache, ab);
}
@@ -1784,8 +1789,12 @@ static struct audit_buffer *audit_buffer_alloc(struct audit_context *ctx,
ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
if (!ab->skb)
goto err;
+
+ skb_queue_head_init(&ab->skb_list);
+ skb_queue_tail(&ab->skb_list, ab->skb);
+
if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0))
- goto err;
+ kfree_skb(ab->skb);
ab->ctx = ctx;
ab->gfp_mask = gfp_mask;
@@ -1849,7 +1858,6 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
int type)
{
struct audit_buffer *ab;
- struct audit_stamp stamp;
if (audit_initialized != AUDIT_INITIALIZED)
return NULL;
@@ -1904,14 +1912,14 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
return NULL;
}
- audit_get_stamp(ab->ctx, &stamp);
+ audit_get_stamp(ab->ctx, &ab->stamp);
/* cancel dummy context to enable supporting records */
if (ctx)
ctx->dummy = 0;
audit_log_format(ab, "audit(%llu.%03lu:%u): ",
- (unsigned long long)stamp.ctime.tv_sec,
- stamp.ctime.tv_nsec/1000000,
- stamp.serial);
+ (unsigned long long)ab->stamp.ctime.tv_sec,
+ ab->stamp.ctime.tv_nsec/1000000,
+ ab->stamp.serial);
return ab;
}
@@ -2167,6 +2175,57 @@ void audit_log_key(struct audit_buffer *ab, char *key)
audit_log_format(ab, "(null)");
}
+/**
+ * audit_buffer_aux_new - Add an aux record buffer to the skb list
+ * @ab: audit_buffer
+ * @type: message type
+ *
+ * Aux records are allocated and added to the skb list of
+ * the "main" record. The ab->skb is reset to point to the
+ * aux record on its creation. When the aux record in complete
+ * ab->skb has to be reset to point to the "main" record.
+ * This allows the audit_log_ functions to be ignorant of
+ * which kind of record it is logging to. It also avoids adding
+ * special data for aux records.
+ *
+ * On success ab->skb will point to the new aux record.
+ * Returns 0 on success, -ENOMEM should allocation fail.
+ */
+static int audit_buffer_aux_new(struct audit_buffer *ab, int type)
+{
+ WARN_ON(ab->skb != skb_peek(&ab->skb_list));
+
+ ab->skb = nlmsg_new(AUDIT_BUFSIZ, ab->gfp_mask);
+ if (!ab->skb)
+ goto err;
+ if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0))
+ goto err;
+ skb_queue_tail(&ab->skb_list, ab->skb);
+
+ audit_log_format(ab, "audit(%llu.%03lu:%u): ",
+ (unsigned long long)ab->stamp.ctime.tv_sec,
+ ab->stamp.ctime.tv_nsec/1000000,
+ ab->stamp.serial);
+
+ return 0;
+
+err:
+ kfree_skb(ab->skb);
+ ab->skb = skb_peek(&ab->skb_list);
+ return -ENOMEM;
+}
+
+/**
+ * audit_buffer_aux_end - Switch back to the "main" record from an aux record
+ * @ab: audit_buffer
+ *
+ * Restores the "main" audit record to ab->skb.
+ */
+static void audit_buffer_aux_end(struct audit_buffer *ab)
+{
+ ab->skb = skb_peek(&ab->skb_list);
+}
+
int audit_log_task_context(struct audit_buffer *ab)
{
int error;
@@ -2402,26 +2461,14 @@ int audit_signal_info(int sig, struct task_struct *t)
}
/**
- * audit_log_end - end one audit record
- * @ab: the audit_buffer
- *
- * We can not do a netlink send inside an irq context because it blocks (last
- * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a
- * queue and a kthread is scheduled to remove them from the queue outside the
- * irq context. May be called in any context.
+ * __audit_log_end - enqueue one audit record
+ * @skb: the buffer to send
*/
-void audit_log_end(struct audit_buffer *ab)
+static void __audit_log_end(struct sk_buff *skb)
{
- struct sk_buff *skb;
struct nlmsghdr *nlh;
- if (!ab)
- return;
-
if (audit_rate_check()) {
- skb = ab->skb;
- ab->skb = NULL;
-
/* setup the netlink header, see the comments in
* kauditd_send_multicast_skb() for length quirks */
nlh = nlmsg_hdr(skb);
@@ -2432,6 +2479,26 @@ void audit_log_end(struct audit_buffer *ab)
wake_up_interruptible(&kauditd_wait);
} else
audit_log_lost("rate limit exceeded");
+}
+
+/**
+ * audit_log_end - end one audit record
+ * @ab: the audit_buffer
+ *
+ * We can not do a netlink send inside an irq context because it blocks (last
+ * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a
+ * queue and a kthread is scheduled to remove them from the queue outside the
+ * irq context. May be called in any context.
+ */
+void audit_log_end(struct audit_buffer *ab)
+{
+ struct sk_buff *skb;
+
+ if (!ab)
+ return;
+
+ while ((skb = skb_dequeue(&ab->skb_list)))
+ __audit_log_end(skb);
audit_buffer_free(ab);
}
--
2.35.1
next prev parent reply other threads:[~2022-06-09 23:15 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220609230146.319210-1-casey.ref@schaufler-ca.com>
2022-06-09 23:01 ` [PATCH v36 00/33] LSM: Module stacking for AppArmor Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 01/33] integrity: disassociate ima_filter_rule from security_audit_rule Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 02/33] LSM: Infrastructure management of the sock security Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 03/33] LSM: Add the lsmblob data structure Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 04/33] LSM: provide lsm name and id slot mappings Casey Schaufler
2022-06-10 7:51 ` kernel test robot
2022-06-09 23:01 ` [PATCH v36 05/33] IMA: avoid label collisions with stacked LSMs Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 06/33] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 07/33] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 08/33] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 09/33] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 10/33] LSM: Use lsmblob in security_ipc_getsecid Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 11/33] LSM: Use lsmblob in security_current_getsecid Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 12/33] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 13/33] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
2022-06-12 19:35 ` kernel test robot
2022-06-09 23:01 ` [PATCH v36 14/33] LSM: Specify which LSM to display Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 15/33] LSM: Ensure the correct LSM context releaser Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 16/33] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 17/33] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 18/33] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
2022-06-10 3:05 ` kernel test robot
2022-06-23 7:09 ` Dan Carpenter
2022-06-09 23:01 ` [PATCH v36 19/33] LSM: security_secid_to_secctx in netlink netfilter Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 20/33] NET: Store LSM netlabel data in a lsmblob Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 21/33] binder: Pass LSM identifier for confirmation Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 22/33] LSM: Extend security_secid_to_secctx to include module selection Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 23/33] Audit: Keep multiple LSM data in audit_names Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 24/33] Audit: Create audit_stamp structure Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 25/33] LSM: Add a function to report multiple LSMs Casey Schaufler
2022-06-09 23:01 ` Casey Schaufler [this message]
2022-06-10 21:04 ` [PATCH v36 26/33] Audit: Allow multiple records in an audit_buffer Paul Moore
2022-06-09 23:01 ` [PATCH v36 27/33] Audit: Add record for multiple task security contexts Casey Schaufler
2022-06-10 21:06 ` Paul Moore
2022-06-09 23:01 ` [PATCH v36 28/33] audit: multiple subject lsm values for netlabel Casey Schaufler
2022-06-10 21:10 ` Paul Moore
2022-06-09 23:01 ` [PATCH v36 29/33] Audit: Add record for multiple object contexts Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 30/33] netlabel: Use a struct lsmblob in audit data Casey Schaufler
2022-06-10 21:12 ` Paul Moore
2022-06-09 23:01 ` [PATCH v36 31/33] LSM: Removed scaffolding function lsmcontext_init Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 32/33] LSM: Add /proc attr entry for full LSM context Casey Schaufler
2022-06-09 23:01 ` [PATCH v36 33/33] AppArmor: Remove the exclusive flag Casey Schaufler
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220609230146.319210-27-casey@schaufler-ca.com \
--to=casey@schaufler-ca.com \
--cc=casey.schaufler@intel.com \
--cc=jmorris@namei.org \
--cc=john.johansen@canonical.com \
--cc=keescook@chromium.org \
--cc=linux-audit@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=paul@paul-moore.com \
--cc=penguin-kernel@i-love.sakura.ne.jp \
--cc=selinux@vger.kernel.org \
--cc=stephen.smalley.work@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).