netfilter: nf_nat: mask out non-verdict bits when checking return value

Same as previous change: we need to mask out the non-verdict bits, as
upcoming patches may embed an errno value in NF_STOLEN verdicts too.

NF_DROP could already do this, but not all called functions do this.

Checks that only test ret vs NF_ACCEPT are fine, the 'errno parts'
are always 0 for those.

Signed-off-by: Florian Westphal <fw@strlen.de>

diff --git a/net/netfilter/nf_nat_proto.c b/net/netfilter/nf_nat_proto.c
index 5a049740758f63b569fe7ff87ead08f784c43527..6d969468c7795b8c2ee6fabfedd79c1860fa38cb 100644 (file)
--- a/net/netfilter/nf_nat_proto.c
+++ b/net/netfilter/nf_nat_proto.c
@@ -999,11 +999,12 @@ static unsigned int
 nf_nat_ipv6_in(void *priv, struct sk_buff *skb,
               const struct nf_hook_state *state)
 {
-       unsigned int ret;
+       unsigned int ret, verdict;
        struct in6_addr daddr = ipv6_hdr(skb)->daddr;
 
        ret = nf_nat_ipv6_fn(priv, skb, state);
-       if (ret != NF_DROP && ret != NF_STOLEN &&
+       verdict = ret & NF_VERDICT_MASK;
+       if (verdict != NF_DROP && verdict != NF_STOLEN &&
            ipv6_addr_cmp(&daddr, &ipv6_hdr(skb)->daddr))
                skb_dst_drop(skb);