[Qemu-devel] [PATCH] tap: clear vhost_net backend on cleanup

["Michael S. Tsirkin" <mst@redhat.com>]

Frontends calling tap_get_vhost_net get an invalid pointer after the
peer backend has been deleted. Jason Wang <jasowang@redhat.com> reports
this leading to a crash in ack_features when we remove the vhost-net
bakend of a virtio nic.

The fix is simply to clear the backend pointer.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---

Jason, could you please confirm whether this patch
will fix the issue you have observed?

Thanks,

 net/tap.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/net/tap.c b/net/tap.c
index 0147dab..4cfa538 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -258,6 +258,7 @@ static void tap_cleanup(VLANClientState *nc)
 
     if (s->vhost_net) {
         vhost_net_cleanup(s->vhost_net);
+        s->vhost_net = NULL;
     }
 
     qemu_purge_queued_packets(nc);
-- 
1.7.3.2.91.g446ac