[PATCH AUTOSEL 5.4 073/175] audit: fix a net reference leak in audit_send_reply()

[PATCH AUTOSEL 5.4 073/175] audit: fix a net reference leak in audit_send_reply()

[Sasha Levin]

From: Paul Moore <paul@paul-moore.com>

[ Upstream commit a48b284b403a4a073d8beb72d2bb33e54df67fb6 ]

If audit_send_reply() fails when trying to create a new thread to
send the reply it also fails to cleanup properly, leaking a reference
to a net structure.  This patch fixes the error path and makes a
handful of other cleanups that came up while fixing the code.

Reported-by: teroincn@gmail.com
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/audit.c | 50 +++++++++++++++++++++++++++++---------------------
 1 file changed, 29 insertions(+), 21 deletions(-)

diff --git a/kernel/audit.c b/kernel/audit.c
index fcfbb3476ccd..a4eeece2eecd 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -923,19 +923,30 @@ struct sk_buff *audit_make_reply(int seq, int type, int done,
 	return NULL;
 }
 
+static void audit_free_reply(struct audit_reply *reply)
+{
+	if (!reply)
+		return;
+
+	if (reply->skb)
+		kfree_skb(reply->skb);
+	if (reply->net)
+		put_net(reply->net);
+	kfree(reply);
+}
+
 static int audit_send_reply_thread(void *arg)
 {
 	struct audit_reply *reply = (struct audit_reply *)arg;
-	struct sock *sk = audit_get_sk(reply->net);
 
 	audit_ctl_lock();
 	audit_ctl_unlock();
 
 	/* Ignore failure. It'll only happen if the sender goes away,
 	   because our timeout is set to infinite. */
-	netlink_unicast(sk, reply->skb, reply->portid, 0);
-	put_net(reply->net);
-	kfree(reply);
+	netlink_unicast(audit_get_sk(reply->net), reply->skb, reply->portid, 0);
+	reply->skb = NULL;
+	audit_free_reply(reply);
 	return 0;
 }
 
@@ -949,35 +960,32 @@ static int audit_send_reply_thread(void *arg)
  * @payload: payload data
  * @size: payload size
  *
- * Allocates an skb, builds the netlink message, and sends it to the port id.
- * No failure notifications.
+ * Allocates a skb, builds the netlink message, and sends it to the port id.
  */
 static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
 			     int multi, const void *payload, int size)
 {
-	struct net *net = sock_net(NETLINK_CB(request_skb).sk);
-	struct sk_buff *skb;
 	struct task_struct *tsk;
-	struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
-					    GFP_KERNEL);
+	struct audit_reply *reply;
 
+	reply = kzalloc(sizeof(*reply), GFP_KERNEL);
 	if (!reply)
 		return;
 
-	skb = audit_make_reply(seq, type, done, multi, payload, size);
-	if (!skb)
-		goto out;
-
-	reply->net = get_net(net);
+	reply->skb = audit_make_reply(seq, type, done, multi, payload, size);
+	if (!reply->skb)
+		goto err;
+	reply->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
 	reply->portid = NETLINK_CB(request_skb).portid;
-	reply->skb = skb;
 
 	tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
-	if (!IS_ERR(tsk))
-		return;
-	kfree_skb(skb);
-out:
-	kfree(reply);
+	if (IS_ERR(tsk))
+		goto err;
+
+	return;
+
+err:
+	audit_free_reply(reply);
 }
 
 /*
-- 
2.25.1


--
Linux-audit mailing list
Linux-audit@redhat.com
https://www.redhat.com/mailman/listinfo/linux-audit

[PATCH AUTOSEL 5.4 079/175] audit: fix a net reference leak in audit_list_rules_send()

[Sasha Levin]

From: Paul Moore <paul@paul-moore.com>

[ Upstream commit 3054d06719079388a543de6adb812638675ad8f5 ]

If audit_list_rules_send() fails when trying to create a new thread
to send the rules it also fails to cleanup properly, leaking a
reference to a net structure.  This patch fixes the error patch and
renames audit_send_list() to audit_send_list_thread() to better
match its cousin, audit_send_reply_thread().

Reported-by: teroincn@gmail.com
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/audit.c       |  2 +-
 kernel/audit.h       |  2 +-
 kernel/auditfilter.c | 16 +++++++---------
 3 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/kernel/audit.c b/kernel/audit.c
index a4eeece2eecd..05ae208ad442 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -879,7 +879,7 @@ static int kauditd_thread(void *dummy)
 	return 0;
 }
 
-int audit_send_list(void *_dest)
+int audit_send_list_thread(void *_dest)
 {
 	struct audit_netlink_list *dest = _dest;
 	struct sk_buff *skb;
diff --git a/kernel/audit.h b/kernel/audit.h
index 6fb7160412d4..ddc22878433d 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -229,7 +229,7 @@ struct audit_netlink_list {
 	struct sk_buff_head q;
 };
 
-int audit_send_list(void *_dest);
+int audit_send_list_thread(void *_dest);
 
 extern int selinux_audit_rule_update(void);
 
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 026e34da4ace..a10e2997aa6c 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1161,11 +1161,8 @@ int audit_rule_change(int type, int seq, void *data, size_t datasz)
  */
 int audit_list_rules_send(struct sk_buff *request_skb, int seq)
 {
-	u32 portid = NETLINK_CB(request_skb).portid;
-	struct net *net = sock_net(NETLINK_CB(request_skb).sk);
 	struct task_struct *tsk;
 	struct audit_netlink_list *dest;
-	int err = 0;
 
 	/* We can't just spew out the rules here because we might fill
 	 * the available socket buffer space and deadlock waiting for
@@ -1173,25 +1170,26 @@ int audit_list_rules_send(struct sk_buff *request_skb, int seq)
 	 * happen if we're actually running in the context of auditctl
 	 * trying to _send_ the stuff */
 
-	dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
+	dest = kmalloc(sizeof(*dest), GFP_KERNEL);
 	if (!dest)
 		return -ENOMEM;
-	dest->net = get_net(net);
-	dest->portid = portid;
+	dest->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
+	dest->portid = NETLINK_CB(request_skb).portid;
 	skb_queue_head_init(&dest->q);
 
 	mutex_lock(&audit_filter_mutex);
 	audit_list_rules(seq, &dest->q);
 	mutex_unlock(&audit_filter_mutex);
 
-	tsk = kthread_run(audit_send_list, dest, "audit_send_list");
+	tsk = kthread_run(audit_send_list_thread, dest, "audit_send_list");
 	if (IS_ERR(tsk)) {
 		skb_queue_purge(&dest->q);
+		put_net(dest->net);
 		kfree(dest);
-		err = PTR_ERR(tsk);
+		return PTR_ERR(tsk);
 	}
 
-	return err;
+	return 0;
 }
 
 int audit_comparator(u32 left, u32 op, u32 right)
-- 
2.25.1


--
Linux-audit mailing list
Linux-audit@redhat.com
https://www.redhat.com/mailman/listinfo/linux-audit