Commit 6a277623 authored Apr 17, 2023 by Min Li Committed by Greg Kroah-Hartman May 30, 2023

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@syzkaller.appspotmail.com>
Link: https://lore.kernel.org/all/000000000000894f5f05f95e9f4d@google.com/


Signed-off-by: Min Li <lm0963hack@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 3ed3c1c2

net/bluetooth/l2cap_core.c

+0 −1

Original line number	Original line	Diff line number	Diff line
	@@ -4392,7 +4392,6 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn,

	chan = l2cap_get_chan_by_scid(conn, scid);		chan = l2cap_get_chan_by_scid(conn, scid);
	if (!chan) {		if (!chan) {
	mutex_unlock(&conn->chan_lock);
	return 0;		return 0;
	}		}