vhost_net: validate sock before trying to put its fd
Sock will be NULL if we pass -1 to vhost_net_set_backend(), but when
we meet errors during ubuf allocation, the code does not check for
NULL before calling sockfd_put(), this will lead NULL
dereferencing. Fixing by checking sock pointer before.
Fixes: bab632d69ee4 ("vhost: vhost TX zero-copy support")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 686dc67..29756d8 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1226,7 +1226,8 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
if (ubufs)
vhost_net_ubuf_put_wait_and_free(ubufs);
err_ubufs:
- sockfd_put(sock);
+ if (sock)
+ sockfd_put(sock);
err_vq:
mutex_unlock(&vq->mutex);
err: