nbd: verify socket is supported during setup (cf1b2326) · Commits · 戴 / test

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: ("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>

drivers/block/nbd.c

+21 −2

Original line number	Diff line number	Diff line
		@@ -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;

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