From: Linus Lüssing Date: Fri, 11 Sep 2015 16:39:48 +0000 (+0200) Subject: bridge: fix igmpv3 / mldv2 report parsing X-Git-Tag: v4.2.3~21 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c5de8f88c0177f3ac724cd4ad4caa685fee11945;p=thirdparty%2Fkernel%2Fstable.git bridge: fix igmpv3 / mldv2 report parsing [ Upstream commit c2d4fbd2163e607915cc05798ce7fb7f31117cc1 ] 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 Tested-by: Tobias Powalowski Signed-off-by: Linus Lüssing Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 1285eaf5dc222..03cdb9e18d576 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -991,7 +991,7 @@ 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); @@ -1052,7 +1052,7 @@ 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;