From 41a8df71809ec0052ce4c0176f2f363c4f783969 Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Tue, 2 Jul 2019 15:00:19 +0300 Subject: [PATCH] net: bridge: mcast: fix stale ipv6 hdr pointer when handling v6 query [ Upstream commit 3b26a5d03d35d8f732d75951218983c0f7f68dff ] We get a pointer to the ipv6 hdr in br_ip6_multicast_query but we may call pskb_may_pull afterwards and end up using a stale pointer. So use the header directly, it's just 1 place where it's needed. Fixes: 08b202b67264 ("bridge br_multicast: IPv6 MLD support.") Signed-off-by: Nikolay Aleksandrov Tested-by: Martin Weinelt Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/bridge/br_multicast.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 2bb52be929ea..fb54d32321ec 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1510,7 +1510,6 @@ static int br_ip6_multicast_query(struct net_bridge *br, struct sk_buff *skb, u16 vid) { - const struct ipv6hdr *ip6h = ipv6_hdr(skb); struct mld_msg *mld; struct net_bridge_mdb_entry *mp; struct mld2_query *mld2q; @@ -1554,7 +1553,7 @@ static int br_ip6_multicast_query(struct net_bridge *br, if (is_general_query) { saddr.proto = htons(ETH_P_IPV6); - saddr.u.ip6 = ip6h->saddr; + saddr.u.ip6 = ipv6_hdr(skb)->saddr; br_multicast_query_received(br, port, &br->ip6_other_query, &saddr, max_delay);