| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.12 03/83] ipv6: fix headroom calculation in udp6_ufo_fragment | Date | Fri, 6 Dec 2013 13:50:53 -0800 |
| |
3.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hannes Frederic Sowa <hannes@stressinduktion.org>
[ Upstream commit 0e033e04c2678dbbe74a46b23fffb7bb918c288e ]
Commit 1e2bd517c108816220f262d7954b697af03b5f9c ("udp6: Fix udp fragmentation for tunnel traffic.") changed the calculation if there is enough space to include a fragment header in the skb from a skb->mac_header dervived one to skb_headroom. Because we already peeled off the skb to transport_header this is wrong. Change this back to check if we have enough room before the mac_header.
This fixes a panic Saran Neti reported. He used the tbf scheduler which skb_gso_segments the skb. The offsets get negative and we panic in memcpy because the skb was erroneously not expanded at the head.
Reported-by: Saran Neti <Saran.Neti@telus.com> Cc: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/ipv6/udp_offload.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/ipv6/udp_offload.c +++ b/net/ipv6/udp_offload.c @@ -88,7 +88,7 @@ static struct sk_buff *udp6_ufo_fragment /* Check if there is enough headroom to insert fragment header. */ tnl_hlen = skb_tnl_header_len(skb); - if (skb_headroom(skb) < (tnl_hlen + frag_hdr_sz)) { + if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) { if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz)) goto out; }
|