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>
This commit is contained in:
Florian Westphal 2023-10-11 09:59:37 +02:00
parent 6291b3a67a
commit 35c038b0a4

View File

@ -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);