From ac5aa2e3332ec04889074afdbd1479424d0227a5 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Fri, 12 Nov 2010 08:26:06 +0100 Subject: [PATCH 1/2] netfilter: NF_HOOK_COND has wrong conditional The NF_HOOK_COND returns 0 when it shouldn't due to what I believe to be an error in the code as the order of operations is not what was intended. C will evalutate == before =. Which means ret is getting set to the bool result, rather than the return value of the function call. The code says if (ret = function() == 1) when it meant to say: if ((ret = function()) == 1) Normally the compiler would warn, but it doesn't notice it because its a actually complex conditional and so the wrong code is wrapped in an explict set of () [exactly what the compiler wants you to do if this was intentional]. Fixing this means that errors when netfilter denies a packet get propagated back up the stack rather than lost. Problem introduced by commit 2249065f (netfilter: get rid of the grossness in netfilter.h). Signed-off-by: Eric Paris Cc: stable@kernel.org Signed-off-by: Patrick McHardy --- include/linux/netfilter.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h index 89341c32631a..03317c8d4077 100644 --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -215,7 +215,7 @@ NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sk_buff *skb, int ret; if (!cond || - (ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, INT_MIN) == 1)) + ((ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, INT_MIN)) == 1)) ret = okfn(skb); return ret; } From 22e091e5253da1e9ad7c0a82c2c84446fc403efe Mon Sep 17 00:00:00 2001 From: Shan Wei Date: Fri, 12 Nov 2010 08:51:55 +0100 Subject: [PATCH 2/2] netfilter: ipv6: fix overlap check for fragments The type of FRAG6_CB(prev)->offset is int, skb->len is *unsigned* int, and offset is int. Without this patch, type conversion occurred to this expression, when (FRAG6_CB(prev)->offset + prev->len) is less than offset. Signed-off-by: Shan Wei Signed-off-by: Patrick McHardy --- net/ipv6/netfilter/nf_conntrack_reasm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index 3a3f129a44cb..79d43aa8fa8d 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -286,7 +286,7 @@ found: /* Check for overlap with preceding fragment. */ if (prev && - (NFCT_FRAG6_CB(prev)->offset + prev->len) - offset > 0) + (NFCT_FRAG6_CB(prev)->offset + prev->len) > offset) goto discard_fq; /* Look for overlap with succeeding segment. */