From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161545Ab3LFWoM (ORCPT ); Fri, 6 Dec 2013 17:44:12 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:60375 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758431Ab3LFVwS (ORCPT ); Fri, 6 Dec 2013 16:52:18 -0500 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 3.12 03/83] ipv6: fix headroom calculation in udp6_ufo_fragment Date: Fri, 6 Dec 2013 13:50:53 -0800 Message-Id: <20131206214640.386606146@linuxfoundation.org> X-Mailer: git-send-email 1.8.5.1.67.gb00d244 In-Reply-To: <20131206214640.002320724@linuxfoundation.org> References: <20131206214640.002320724@linuxfoundation.org> User-Agent: quilt/0.60-8.1.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.12-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 @@ -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; }