From 4b275d7efa1c4412f0d572fcd7f78ed0919370b3 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Tue, 23 Aug 2011 22:54:33 +0000 Subject: bridge: Pseudo-header required for the checksum of ICMPv6 Checksum of ICMPv6 is not properly computed because the pseudo header is not used. Thus, the MLD packet gets dropped by the bridge. Signed-off-by: Zheng Yan Reported-by: Ang Way Chuang Signed-off-by: David S. Miller --- net/bridge/br_multicast.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'net/bridge/br_multicast.c') diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 2d85ca7111d3..22d2d1af1c83 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1520,16 +1520,23 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br, err = pskb_trim_rcsum(skb2, len); if (err) goto out; + err = -EINVAL; } + ip6h = ipv6_hdr(skb2); + switch (skb2->ip_summed) { case CHECKSUM_COMPLETE: - if (!csum_fold(skb2->csum)) + if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, skb2->len, + IPPROTO_ICMPV6, skb2->csum)) break; /*FALLTHROUGH*/ case CHECKSUM_NONE: - skb2->csum = 0; - if (skb_checksum_complete(skb2)) + skb2->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr, + &ip6h->daddr, + skb2->len, + IPPROTO_ICMPV6, 0)); + if (__skb_checksum_complete(skb2)) goto out; } -- cgit v1.2.3 From 22df13319d1fec30b8f9bcaadc295829647109bb Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 23 Aug 2011 19:57:05 +0000 Subject: bridge: fix a possible use after free br_multicast_ipv6_rcv() can call pskb_trim_rcsum() and therefore skb head can be reallocated. Cache icmp6_type field instead of dereferencing twice the struct icmp6hdr pointer. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/bridge/br_multicast.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'net/bridge/br_multicast.c') diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index 22d2d1af1c83..995cbe0ac0b2 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -1456,7 +1456,7 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br, { struct sk_buff *skb2; const struct ipv6hdr *ip6h; - struct icmp6hdr *icmp6h; + u8 icmp6_type; u8 nexthdr; unsigned len; int offset; @@ -1502,9 +1502,9 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br, __skb_pull(skb2, offset); skb_reset_transport_header(skb2); - icmp6h = icmp6_hdr(skb2); + icmp6_type = icmp6_hdr(skb2)->icmp6_type; - switch (icmp6h->icmp6_type) { + switch (icmp6_type) { case ICMPV6_MGM_QUERY: case ICMPV6_MGM_REPORT: case ICMPV6_MGM_REDUCTION: @@ -1544,7 +1544,7 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br, BR_INPUT_SKB_CB(skb)->igmp = 1; - switch (icmp6h->icmp6_type) { + switch (icmp6_type) { case ICMPV6_MGM_REPORT: { struct mld_msg *mld; -- cgit v1.2.3