[PATCH 5.10.y] Bluetooth: SCO: Fix use-after-free in sco_recv_frame() due to missing sock_hold

[PATCH 5.10.y] Bluetooth: SCO: Fix use-after-free in sco_recv_frame() due to missing sock_hold

[Jianqiang kang]

From: Hyunwoo Kim <imv4bel@gmail.com>

[ Upstream commit 598dbba9919c5e36c54fe1709b557d64120cb94b ]

sco_recv_frame() reads conn->sk under sco_conn_lock() but immediately
releases the lock without holding a reference to the socket. A concurrent
close() can free the socket between the lock release and the subsequent
sk->sk_state access, resulting in a use-after-free.

Other functions in the same file (sco_sock_timeout(), sco_conn_del())
correctly use sco_sock_hold() to safely hold a reference under the lock.

Fix by using sco_sock_hold() to take a reference before releasing the
lock, and adding sock_put() on all exit paths.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Jianqiang kang <jianqkang@sina.cn>
---
 net/bluetooth/sco.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index ce084a184a1c..c441e5225458 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -305,7 +305,7 @@ static void sco_recv_frame(struct sco_conn *conn, struct sk_buff *skb)
 	struct sock *sk;
 
 	sco_conn_lock(conn);
-	sk = conn->sk;
+	sk = sco_sock_hold(conn);
 	sco_conn_unlock(conn);
 
 	if (!sk)
@@ -314,11 +314,15 @@ static void sco_recv_frame(struct sco_conn *conn, struct sk_buff *skb)
 	BT_DBG("sk %p len %d", sk, skb->len);
 
 	if (sk->sk_state != BT_CONNECTED)
-		goto drop;
+		goto drop_put;
 
-	if (!sock_queue_rcv_skb(sk, skb))
+	if (!sock_queue_rcv_skb(sk, skb)) {
+		sock_put(sk);
 		return;
+	}
 
+drop_put:
+	sock_put(sk);
 drop:
 	kfree_skb(skb);
 }
-- 
2.34.1

RE: [5.10.y] Bluetooth: SCO: Fix use-after-free in sco_recv_frame() due to missing sock_hold

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 540 bytes --]

This is an automated email and please do not reply to this email.

Dear Submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
While preparing the CI tests, the patches you submitted couldn't be applied to the current HEAD of the repository.

----- Output -----

error: patch failed: net/bluetooth/sco.c:305
error: net/bluetooth/sco.c: patch does not apply
hint: Use 'git am --show-current-patch' to see the failed patch

Please resolve the issue and submit the patches again.


---
Regards,
Linux Bluetooth