From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Saran Neti , Pravin B Shelar , Hannes Frederic Sowa , "David S. Miller" Subject: [PATCH 3.10 01/58] ipv6: fix headroom calculation in udp6_ufo_fragment Date: Fri, 6 Dec 2013 13:51:32 -0800 Message-Id: <20131206214845.052072777@linuxfoundation.org> In-Reply-To: <20131206214844.906193530@linuxfoundation.org> References: <20131206214844.906193530@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hannes Frederic Sowa [ 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 Cc: Pravin B Shelar Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- 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 @@ -85,7 +85,7 @@ 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; }