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 99D6BC61DA2 for ; Tue, 24 Jan 2023 18:41:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233508AbjAXSlC (ORCPT ); Tue, 24 Jan 2023 13:41:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233638AbjAXSk7 (ORCPT ); Tue, 24 Jan 2023 13:40:59 -0500 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3563C460AE; Tue, 24 Jan 2023 10:40:35 -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 2/4] netfilter: conntrack: fix bug in for_each_sctp_chunk Date: Tue, 24 Jan 2023 19:39:31 +0100 Message-Id: <20230124183933.4752-3-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230124183933.4752-1-pablo@netfilter.org> References: <20230124183933.4752-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org From: Sriram Yagnaraman skb_header_pointer() will return NULL if offset + sizeof(_sch) exceeds skb->len, so this offset < skb->len test is redundant. if sch->length == 0, this will end up in an infinite loop, add a check for sch->length > 0 Fixes: 9fb9cbb1082d ("[NETFILTER]: Add nf_conntrack subsystem.") Suggested-by: Florian Westphal Signed-off-by: Sriram Yagnaraman Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_proto_sctp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c index 2b2c549ba678..c561c1213704 100644 --- a/net/netfilter/nf_conntrack_proto_sctp.c +++ b/net/netfilter/nf_conntrack_proto_sctp.c @@ -160,8 +160,8 @@ static void sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct) #define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) \ for ((offset) = (dataoff) + sizeof(struct sctphdr), (count) = 0; \ - (offset) < (skb)->len && \ - ((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch))); \ + ((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch))) && \ + (sch)->length; \ (offset) += (ntohs((sch)->length) + 3) & ~3, (count)++) /* Some validity checks to make sure the chunks are fine */ -- 2.30.2