From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D335C54EBE for ; Mon, 2 Jan 2023 16:40:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236419AbjABQkl (ORCPT ); Mon, 2 Jan 2023 11:40:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233048AbjABQki (ORCPT ); Mon, 2 Jan 2023 11:40:38 -0500 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id B381A2BE8; Mon, 2 Jan 2023 08:40:34 -0800 (PST) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com Subject: [PATCH net 1/7] netfilter: conntrack: fix ipv6 exthdr error check Date: Mon, 2 Jan 2023 17:40:19 +0100 Message-Id: <20230102164025.125995-2-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230102164025.125995-1-pablo@netfilter.org> References: <20230102164025.125995-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Florian Westphal 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: a70e483460d5 ("netfilter: conntrack: merge ipv4+ipv6 confirm functions") Reported-by: kernel test robot Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_proto.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c index 99323fb12d0f..ccef340be575 100644 --- a/net/netfilter/nf_conntrack_proto.c +++ b/net/netfilter/nf_conntrack_proto.c @@ -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); -- 2.30.2