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| author | Luiz Augusto von Dentz <luiz.von.dentz@intel.com> | 2024-09-30 13:26:21 -0400 |
|---|---|---|
| committer | Luiz Augusto von Dentz <luiz.von.dentz@intel.com> | 2024-10-04 16:54:10 -0400 |
| commit | 08d1914293dae38350b8088980e59fbc699a72fe (patch) | |
| tree | 0310164efb55ea905445a350d443b7d0d08b0c79 | |
| parent | 500257db81d067c1ad5a202501a085a8ffea10f1 (diff) | |
| download | lwn-08d1914293dae38350b8088980e59fbc699a72fe.tar.gz lwn-08d1914293dae38350b8088980e59fbc699a72fe.zip | |
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>
| -rw-r--r-- | net/bluetooth/rfcomm/sock.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c index 37d63d768afb..f48250e3f2e1 100644 --- a/net/bluetooth/rfcomm/sock.c +++ b/net/bluetooth/rfcomm/sock.c @@ -865,9 +865,7 @@ static int rfcomm_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned lon if (err == -ENOIOCTLCMD) { #ifdef CONFIG_BT_RFCOMM_TTY - lock_sock(sk); err = rfcomm_dev_ioctl(sk, cmd, (void __user *) arg); - release_sock(sk); #else err = -EOPNOTSUPP; #endif |