tree 75be589c2bcf36be09c34b8f642c0e0e8b84a61a
parent 962399bb7fbf5ce0c5b768ca7115614f31ff8f3f
author Mike Christie <mchristi@redhat.com> 1571347654 -0500
committer Jens Axboe <axboe@kernel.dk> 1572035841 -0600

nbd: verify socket is supported during setup

nbd requires socket families to support the shutdown method so the nbd
recv workqueue can be woken up from its sock_recvmsg call. If the socket
does not support the callout we will leave recv works running or get hangs
later when the device or module is removed.

This adds a check during socket connection/reconnection to make sure the
socket being passed in supports the needed callout.

Reported-by: syzbot+24c12fa8d218ed26011a@syzkaller.appspotmail.com
Fixes: e9e006f5fcf2 ("nbd: fix max number of supported devs")
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>