From: Archie Pusaka apusaka@chromium.org
[ Upstream commit 3af70b39fa2d415dc86c370e5b24ddb9fdacbd6f ]
There is a possibility of receiving a zapped sock on l2cap_sock_connect(). This could lead to interesting crashes, one such case is tearing down an already tore l2cap_sock as is happened with this call trace:
__dump_stack lib/dump_stack.c:15 [inline] dump_stack+0xc4/0x118 lib/dump_stack.c:56 register_lock_class kernel/locking/lockdep.c:792 [inline] register_lock_class+0x239/0x6f6 kernel/locking/lockdep.c:742 __lock_acquire+0x209/0x1e27 kernel/locking/lockdep.c:3105 lock_acquire+0x29c/0x2fb kernel/locking/lockdep.c:3599 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:137 [inline] _raw_spin_lock_bh+0x38/0x47 kernel/locking/spinlock.c:175 spin_lock_bh include/linux/spinlock.h:307 [inline] lock_sock_nested+0x44/0xfa net/core/sock.c:2518 l2cap_sock_teardown_cb+0x88/0x2fb net/bluetooth/l2cap_sock.c:1345 l2cap_chan_del+0xa3/0x383 net/bluetooth/l2cap_core.c:598 l2cap_chan_close+0x537/0x5dd net/bluetooth/l2cap_core.c:756 l2cap_chan_timeout+0x104/0x17e net/bluetooth/l2cap_core.c:429 process_one_work+0x7e3/0xcb0 kernel/workqueue.c:2064 worker_thread+0x5a5/0x773 kernel/workqueue.c:2196 kthread+0x291/0x2a6 kernel/kthread.c:211 ret_from_fork+0x4e/0x80 arch/x86/entry/entry_64.S:604
Signed-off-by: Archie Pusaka apusaka@chromium.org Reported-by: syzbot+abfc0f5e668d4099af73@syzkaller.appspotmail.com Reviewed-by: Alain Michaud alainm@chromium.org Reviewed-by: Abhishek Pandit-Subedi abhishekpandit@chromium.org Reviewed-by: Guenter Roeck groeck@chromium.org Signed-off-by: Marcel Holtmann marcel@holtmann.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/bluetooth/l2cap_sock.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 8648c5211ebe..e693fee08623 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -179,9 +179,17 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, struct l2cap_chan *chan = l2cap_pi(sk)->chan; struct sockaddr_l2 la; int len, err = 0; + bool zapped;
BT_DBG("sk %p", sk);
+ lock_sock(sk); + zapped = sock_flag(sk, SOCK_ZAPPED); + release_sock(sk); + + if (zapped) + return -EINVAL; + if (!addr || alen < offsetofend(struct sockaddr, sa_family) || addr->sa_family != AF_BLUETOOTH) return -EINVAL;