From 3c47b10c7a3a86d6fb5fb15a0c41fe512ed44f87 Mon Sep 17 00:00:00 2001
From: Xiao Wang <jasowang@redhat.com>
Date: Thu, 14 Nov 2013 09:40:26 +0100
Subject: [PATCH 02/14] virtio-net: only delete bh that existed

RH-Author: Xiao Wang <jasowang@redhat.com>
Message-id: <1384422026-7632-1-git-send-email-jasowang@redhat.com>
Patchwork-id: 55681
O-Subject: [RHEL7.0 qemu-kvm PATCH] virtio-net: only delete bh that existed
Bugzilla: 922463
RH-Acked-by: Amos Kong <akong@redhat.com>
RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>
RH-Acked-by: Markus Armbruster <armbru@redhat.com>
RH-Acked-by: Vlad Yasevich <vyasevic@redhat.com>

bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=922463
upstream: 6b9b8758c15f3bc2875dbd6e2d03c5362b8d6902
brew build: https://brewweb.devel.redhat.com/taskinfo?taskID=6576713
test status: tested by my self

We delete without check whether it existed during exit. This will lead NULL
pointer deference since it was created conditionally depends on guest driver
status and features. So add a check of existence before trying to delete it.

Cc: qemu-stable@nongnu.org
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/net/virtio-net.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 hw/net/virtio-net.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 19c5030..f889841 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -1532,7 +1532,7 @@ static int virtio_net_device_exit(DeviceState *qdev)
         if (q->tx_timer) {
             qemu_del_timer(q->tx_timer);
             qemu_free_timer(q->tx_timer);
-        } else {
+        } else if (q->tx_bh) {
             qemu_bh_delete(q->tx_bh);
         }
     }
-- 
1.7.1