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 <[email protected]> Cc: "Michael S. Tsirkin" <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Signed-off-by: Sasha Levin <[email protected]> --- 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 0c7321c..bde0dec 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; -- 1.7.6.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
