virtio_net: verify if queue is broken after virtqueue_get_buf()

If a virtqueue_get_buf() call returns a NULL pointer a possibly endless while
loop should be avoided by checking for a broken virtqueue.

Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index ff208d2787d3..057ea133cd2b 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -825,7 +825,8 @@ static bool virtnet_send_command(struct virtnet_info *vi, u8 class, u8 cmd,
         /* Spin for a response, the kick causes an ioport write, trapping
          * into the hypervisor, so the request should be handled immediately.
          */
-        while (!virtqueue_get_buf(vi->cvq, &tmp))
+        while (!virtqueue_get_buf(vi->cvq, &tmp) &&
+               !virtqueue_is_broken(vi->cvq))
                 cpu_relax();
 
         return status == VIRTIO_NET_OK;