• Luiz Augusto von Dentz's avatar
    Bluetooth: RFCOMM: FIX possible deadlock in rfcomm_sk_state_change · 08d19142
    Luiz Augusto von Dentz authored
    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-gfe46a7dd #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: 3241ad82 ("[Bluetooth] Add timestamp support to L2CAP, RFCOMM and SCO")
    Signed-off-by: default avatarLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
    08d19142
sock.c 22.3 KB