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| author | Sasha Levin <levinsasha928@gmail.com> | 2011-09-28 04:40:54 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-10-06 15:39:40 -0400 |
| commit | e878d78b9a7403fabc89ecc93c56928b74d14f01 (patch) | |
| tree | 669468cdee79d003f70321dcf6d1710b0b6bb852 | |
| parent | 515853ccecc6987dfb8ed809dd8bf8900286f29e (diff) | |
| download | linux-next-e878d78b9a7403fabc89ecc93c56928b74d14f01.tar.gz | |
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>
| -rw-r--r-- | drivers/net/virtio_net.c | 13 |
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; |