Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755120Ab2JGXny (ORCPT ); Sun, 7 Oct 2012 19:43:54 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:38244 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752678Ab2JGXWL (ORCPT ); Sun, 7 Oct 2012 19:22:11 -0400 Message-Id: <20121007225848.396468237@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 08 Oct 2012 00:00:13 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Eric Dumazet , "David S. Miller" Subject: [ 099/108] ipv6: mip6: fix mip6_mh_filter() In-Reply-To: <20121007225834.673681075@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2332 Lines: 71 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 96af69ea2a83d292238bdba20e4508ee967cf8cb ] mip6_mh_filter() should not modify its input, or else its caller would need to recompute ipv6_hdr() if skb->head is reallocated. Use skb_header_pointer() instead of pskb_may_pull() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/ipv6/mip6.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/net/ipv6/mip6.c b/net/ipv6/mip6.c index 43242e6..42853c4 100644 --- a/net/ipv6/mip6.c +++ b/net/ipv6/mip6.c @@ -84,28 +84,30 @@ static int mip6_mh_len(int type) static int mip6_mh_filter(struct sock *sk, struct sk_buff *skb) { - struct ip6_mh *mh; + struct ip6_mh _hdr; + const struct ip6_mh *mh; - if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) || - !pskb_may_pull(skb, (skb_transport_offset(skb) + - ((skb_transport_header(skb)[1] + 1) << 3)))) + mh = skb_header_pointer(skb, skb_transport_offset(skb), + sizeof(_hdr), &_hdr); + if (!mh) return -1; - mh = (struct ip6_mh *)skb_transport_header(skb); + if (((mh->ip6mh_hdrlen + 1) << 3) > skb->len) + return -1; if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) { LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n", mh->ip6mh_hdrlen, mip6_mh_len(mh->ip6mh_type)); - mip6_param_prob(skb, 0, ((&mh->ip6mh_hdrlen) - - skb_network_header(skb))); + mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_hdrlen) + + skb_network_header_len(skb)); return -1; } if (mh->ip6mh_proto != IPPROTO_NONE) { LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n", mh->ip6mh_proto); - mip6_param_prob(skb, 0, ((&mh->ip6mh_proto) - - skb_network_header(skb))); + mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_proto) + + skb_network_header_len(skb)); return -1; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/