]> www.infradead.org Git - users/willy/pagecache.git/commit
Bluetooth: RFCOMM: FIX possible deadlock in rfcomm_sk_state_change
authorLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
Mon, 30 Sep 2024 17:26:21 +0000 (13:26 -0400)
committerLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
Fri, 4 Oct 2024 20:54:10 +0000 (16:54 -0400)
commit08d1914293dae38350b8088980e59fbc699a72fe
tree0310164efb55ea905445a350d443b7d0d08b0c79
parent500257db81d067c1ad5a202501a085a8ffea10f1
Bluetooth: RFCOMM: FIX possible deadlock in rfcomm_sk_state_change

rfcomm_sk_state_change attempts to use sock_lock so it must never be
called with it locked but rfcomm_sock_ioctl always attempt to lock it
causing the following trace:

======================================================
WARNING: possible circular locking dependency detected
6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted
------------------------------------------------------
syz-executor386/5093 is trying to acquire lock:
ffff88807c396258 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1671 [inline]
ffff88807c396258 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: rfcomm_sk_state_change+0x5b/0x310 net/bluetooth/rfcomm/sock.c:73

but task is already holding lock:
ffff88807badfd28 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x226/0x6a0 net/bluetooth/rfcomm/core.c:491

Reported-by: syzbot+d7ce59b06b3eb14fd218@syzkaller.appspotmail.com
Tested-by: syzbot+d7ce59b06b3eb14fd218@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=d7ce59b06b3eb14fd218
Fixes: 3241ad820dbb ("[Bluetooth] Add timestamp support to L2CAP, RFCOMM and SCO")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
net/bluetooth/rfcomm/sock.c