Michael S. Tsirkin writes:
> Frontends calling tap_get_vhost_net get an invalid pointer after the
> peer backend has been deleted. Jason Wang <jasow...@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 <m...@redhat.com>
> ---
>
> Jason, could you please confirm whether this patch
> will fix the issue you have observed?
>
> Thanks,
>
Yes it does, and how about also add assign fd to -1 in tap_cleanup()
and then check it in virtio_net_set_features() otherwise we could get
warning of the failure of offload setting?
> 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
