[PATCH] 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")
Signed-off-by: Mike Christie <mchristi@redhat.com>
---
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 478aa86fc1f2..7bd9e92f6bb7 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -972,6 +972,25 @@ 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)
{
@@ -981,7 +1000,7 @@ 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;
@@ -1033,7 +1052,7 @@ 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;
--
2.20.1
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