Commit 5eb119da authored by Florian Westphal's avatar Florian Westphal Committed by Pablo Neira Ayuso
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netfilter: conntrack: fix ipv6 exthdr error check 



smatch warnings:
net/netfilter/nf_conntrack_proto.c:167 nf_confirm() warn: unsigned 'protoff' is never less than zero.

We need to check if ipv6_skip_exthdr() returned an error, but protoff is
unsigned.  Use a signed integer for this.

Fixes: a70e4834 ("netfilter: conntrack: merge ipv4+ipv6 confirm functions")
Reported-by: default avatarkernel test robot <lkp@intel.com>
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 19e72b06

net/netfilter/nf_conntrack_proto.c

+5 −2
Original line number Diff line number Diff line
@@ -141,6 +141,7 @@ unsigned int nf_confirm(void *priv, 
	struct nf_conn *ct;

	bool seqadj_needed;

	__be16 frag_off;

	int start;

	u8 pnum;



	ct = nf_ct_get(skb, &ctinfo);
@@ -163,9 +164,11 @@ unsigned int nf_confirm(void *priv, 
		break;

	case NFPROTO_IPV6:

		pnum = ipv6_hdr(skb)->nexthdr;

		protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum, &frag_off);

		if (protoff < 0 || (frag_off & htons(~0x7)) != 0)

		start = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum, &frag_off);

		if (start < 0 || (frag_off & htons(~0x7)) != 0)

			return nf_conntrack_confirm(skb);



		protoff = start;

		break;

	default:

		return nf_conntrack_confirm(skb);