From: Mike Christie mchristi@redhat.com
[ Upstream commit cf1b2326b734896734c6e167e41766f9cee7686a ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/block/nbd.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index d445195945618..bd9aafe86c2fc 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -924,6 +924,25 @@ 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) { @@ -933,7 +952,7 @@ 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;
@@ -985,7 +1004,7 @@ 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;