[patch 12/19] [BRIDGE-NF]: Fix bridge-nf ipv6 length check

Greg Kroah-Hartman
2005-12-23T22:54:05Z

[-- Attachment #1: fix-bridge-nf-ipv6-length-check.patch --]
[-- Type: text/plain, Size: 1760 bytes --]

-stable review patch. If anyone has any objections, please let us know.

------------------
From: Bart De Schuymer <bdschuym@pandora.be>

A typo caused some bridged IPv6 packets to get dropped randomly,
as reported by Sebastien Chaumontet. The patch below fixes this
(using skb->nh.raw instead of raw) and also makes the jumbo packet
length checking up-to-date with the code in
net/ipv6/exthdrs.c::ipv6_hop_jumbo.

Signed-off-by: Bart De Schuymer <bdschuym@pandora.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
net/bridge/br_netfilter.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)

--- linux-2.6.14.4.orig/net/bridge/br_netfilter.c
+++ linux-2.6.14.4/net/bridge/br_netfilter.c
@@ -295,7 +295,7 @@ static int check_hbh_len(struct sk_buff
len -= 2;

while (len > 0) {
- int optlen = raw[off+1]+2;
+ int optlen = skb->nh.raw[off+1]+2;

switch (skb->nh.raw[off]) {
case IPV6_TLV_PAD0:
@@ -308,18 +308,15 @@ static int check_hbh_len(struct sk_buff
case IPV6_TLV_JUMBO:
if (skb->nh.raw[off+1] != 4 || (off&3) != 2)
goto bad;
-
pkt_len = ntohl(*(u32*)(skb->nh.raw+off+2));
-
+ if (pkt_len <= IPV6_MAXPLEN ||
+ skb->nh.ipv6h->payload_len)
+ goto bad;
if (pkt_len > skb->len - sizeof(struct ipv6hdr))
goto bad;
- if (pkt_len + sizeof(struct ipv6hdr) < skb->len) {
- if (__pskb_trim(skb,
- pkt_len + sizeof(struct ipv6hdr)))
- goto bad;
- if (skb->ip_summed == CHECKSUM_HW)
- skb->ip_summed = CHECKSUM_NONE;
- }
+ if (pskb_trim_rcsum(skb,
+ pkt_len+sizeof(struct ipv6hdr)))
+ goto bad;
break;
default:
if (optlen > len)

--