This is a note to let you know that I've just added the patch titled
Bluetooth: L2CAP: fix "bad unlock balance" in l2cap_disconnect_rsp
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bluetooth-l2cap-fix-bad-unlock-balance-in-l2cap_disc.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f263e6c509d7650eaf9280c65f75a09ebb53372e
Author: Min Li <lm0963hack@xxxxxxxxx>
Date: Mon Apr 17 10:27:54 2023 +0800
Bluetooth: L2CAP: fix "bad unlock balance" in l2cap_disconnect_rsp
[ Upstream commit 25e97f7b1866e6b8503be349eeea44bb52d661ce ]
conn->chan_lock isn't acquired before l2cap_get_chan_by_scid,
if l2cap_get_chan_by_scid returns NULL, then 'bad unlock balance'
is triggered.
Reported-by: syzbot+9519d6b5b79cf7787cf3@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://lore.kernel.org/all/000000000000894f5f05f95e9f4d@xxxxxxxxxx/
Signed-off-by: Min Li <lm0963hack@xxxxxxxxx>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 1a68aad5737e1..94d40a20ab958 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -4392,7 +4392,6 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn,
chan = l2cap_get_chan_by_scid(conn, scid);
if (!chan) {
- mutex_unlock(&conn->chan_lock);
return 0;
}
