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: e9e006f5fc ("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>
This commit is contained in:
Mike Christie 2019-10-17 16:27:34 -05:00 committed by Jens Axboe
parent 962399bb7f
commit cf1b2326b7

View File

@ -980,6 +980,25 @@ static blk_status_t nbd_queue_rq(struct blk_mq_hw_ctx *hctx,
return ret;
}
static struct socket *nbd_get_socket(struct nbd_device *nbd, unsigned long fd,
int *err)
{
struct socket *sock;
*err = 0;
sock = sockfd_lookup(fd, err);
if (!sock)
return NULL;
if (sock->ops->shutdown == sock_no_shutdown) {
dev_err(disk_to_dev(nbd->disk), "Unsupported socket: shutdown callout must be supported.\n");
*err = -EINVAL;
return NULL;
}
return sock;
}
static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg,
bool netlink)
{
@ -989,7 +1008,7 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg,
struct nbd_sock *nsock;
int err;
sock = sockfd_lookup(arg, &err);
sock = nbd_get_socket(nbd, arg, &err);
if (!sock)
return err;
@ -1041,7 +1060,7 @@ static int nbd_reconnect_socket(struct nbd_device *nbd, unsigned long arg)
int i;
int err;
sock = sockfd_lookup(arg, &err);
sock = nbd_get_socket(nbd, arg, &err);
if (!sock)
return err;