path: root/drivers/net
diff options
authorSasha Levin <levinsasha928@gmail.com>2011-09-28 04:40:54 +0000
committerDavid S. Miller <davem@davemloft.net>2011-10-06 15:39:40 -0400
commite878d78b9a7403fabc89ecc93c56928b74d14f01 (patch)
tree669468cdee79d003f70321dcf6d1710b0b6bb852 /drivers/net
parent515853ccecc6987dfb8ed809dd8bf8900286f29e (diff)
virtio-net: Verify page list size before fitting into skb
This patch verifies that the length of a buffer stored in a linked list of pages is small enough to fit into a skb. If the size is larger than a max size of a skb, it means that we shouldn't go ahead building skbs anyway since we won't be able to send the buffer as the user requested. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: virtualization@lists.linux-foundation.org Cc: netdev@vger.kernel.org Cc: kvm@vger.kernel.org Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index d6e93ba9ff47..b8225f3b31d1 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -195,6 +195,19 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
len -= copy;
offset += copy;
+ /*
+ * Verify that we can indeed put this data into a skb.
+ * This is here to handle cases when the device erroneously
+ * tries to receive more than is possible. This is usually
+ * the case of a broken device.
+ */
+ if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) {
+ if (net_ratelimit())
+ pr_debug("%s: too much data\n", skb->dev->name);
+ dev_kfree_skb(skb);
+ return NULL;
+ }
while (len) {
set_skb_frag(skb, page, offset, &len);
page = (struct page *)page->private;