From c2d4fbd2163e607915cc05798ce7fb7f31117cc1 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Linus=20L=C3=BCssing?= <linus.luessing@c0d3.blue>
Date: Fri, 11 Sep 2015 18:39:48 +0200
Subject: [PATCH] bridge: fix igmpv3 / mldv2 report parsing
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit
With the newly introduced helper functions the skb pulling is hidden in
the checksumming function - and undone before returning to the caller.
The IGMPv3 and MLDv2 report parsing functions in the bridge still
assumed that the skb is pointing to the beginning of the IGMP/MLD
message while it is now kept at the beginning of the IPv4/6 header,
breaking the message parsing and creating packet loss.
Fixing this by taking the offset between IP and IGMP/MLD header into
account, too.
Fixes: 9afd85c9e455 ("net: Export IGMP/MLD message validation code")
Reported-by: Tobias Powalowski <tobias.powalowski@googlemail.com>
Tested-by: Tobias Powalowski <tobias.powalowski@googlemail.com>
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/bridge/br_multicast.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 66efdc21f5485..480b3de1a0e3e 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -1006,7 +1006,7 @@ static int br_ip4_multicast_igmp3_report(struct net_bridge *br,
ih = igmpv3_report_hdr(skb);
num = ntohs(ih->ngrec);
- len = sizeof(*ih);
+ len = skb_transport_offset(skb) + sizeof(*ih);
for (i = 0; i < num; i++) {
len += sizeof(*grec);
@@ -1067,7 +1067,7 @@ static int br_ip6_multicast_mld2_report(struct net_bridge *br,
icmp6h = icmp6_hdr(skb);
num = ntohs(icmp6h->icmp6_dataun.un_data16[1]);
- len = sizeof(*icmp6h);
+ len = skb_transport_offset(skb) + sizeof(*icmp6h);
for (i = 0; i < num; i++) {
__be16 *nsrcs, _nsrcs;
--
2.30.2