[PATCH 3.8 162/166] virtio_net: don't leak memory or block when too many frags

Kamal Mostafa
2014-01-15T21:52:56Z

From: "Michael S. Tsirkin" <mst@redhat.com>

We leak an skb when there are too many frags,
we also stop processing the packet in the middle,
the result is almost sure to be loss of networking.

Reported-by: Michael Dalton <mwdalton@google.com>
Acked-by: Michael Dalton <mwdalton@google.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
drivers/net/virtio_net.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 840cf2f..8f009899 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -341,7 +341,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
if (i >= MAX_SKB_FRAGS) {
pr_debug("%s: packet too long\n", skb->dev->name);
skb->dev->stats.rx_length_errors++;
- return NULL;
+ goto err_frags;
}
page = virtqueue_get_buf(rq->vq, &len);
if (!page) {
@@ -362,6 +362,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
err_skb:
give_pages(rq, page);
while (--num_buf) {
+err_frags:
buf = virtqueue_get_buf(rq->vq, &len);
if (unlikely(!buf)) {
pr_debug("%s: rx error: %d buffers missing\n",
--
1.8.3.2