From 0749e3dd154b2c16010396e0fbad7b38c7131128 Mon Sep 17 00:00:00 2001 From: David S. Miller Date: Wed, 8 Dec 2010 18:42:23 -0800 Subject: [PATCH] econet: Fix crash in aun_incoming(). CVE-2010-4342 CVE-2010-4342 BugLink: http://bugs.launchpad.net/bugs/736394 Unconditional use of skb->dev won't work here, try to fetch the econet device via skb_dst()->dev instead. Suggested by Eric Dumazet. Reported-by: Nelson Elhage Tested-by: Nelson Elhage Signed-off-by: David S. Miller (backport of upstream commit 4e085e76cbe558b79b54cbab772f61185879bc64) Signed-off-by: Leann Ogasawara --- net/econet/af_econet.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/net/econet/af_econet.c b/net/econet/af_econet.c index 690da47..6bc2f6d 100644 --- a/net/econet/af_econet.c +++ b/net/econet/af_econet.c @@ -844,8 +844,12 @@ static void aun_incoming(struct sk_buff *skb, struct aunhdr *ah, size_t len) struct iphdr *ip = ip_hdr(skb); unsigned char stn = ntohl(ip->saddr) & 0xff; struct sock *sk; + struct dst_entry *dst = skb_dst(skb); + struct ec_device *edev = NULL; struct sk_buff *newskb; - struct ec_device *edev = skb->dev->ec_ptr; + + if (dst) + edev = dst->dev->ec_ptr; if (! edev) goto bad; -- 1.7.0.4