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 1EBA2C433EF for ; Wed, 5 Jan 2022 15:26:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230193AbiAEP0T (ORCPT ); Wed, 5 Jan 2022 10:26:19 -0500 Received: from mail.netfilter.org ([217.70.188.207]:33056 "EHLO mail.netfilter.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230073AbiAEP0T (ORCPT ); Wed, 5 Jan 2022 10:26:19 -0500 Received: from localhost.localdomain (unknown [78.30.32.163]) by mail.netfilter.org (Postfix) with ESMTPSA id 9827C62BD8 for ; Wed, 5 Jan 2022 16:23:32 +0100 (CET) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Subject: [PATCH nf] netfilter: nft_payload: do not update layer 4 checksum when mangling fragments Date: Wed, 5 Jan 2022 16:26:13 +0100 Message-Id: <20220105152613.14133-1-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org IP fragments do not come with the transport header, hence skip bogus layer 4 checksum updates. Reported-by: Steffen Weinreich Tested-by: Steffen Weinreich Fixes: 1814096980bb ("netfilter: nft_payload: layer 4 checksum adjustment for pseudoheader fields") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_payload.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index bd689938a2e0..58e96a0fe0b4 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -546,6 +546,9 @@ static int nft_payload_l4csum_offset(const struct nft_pktinfo *pkt, struct sk_buff *skb, unsigned int *l4csum_offset) { + if (pkt->fragoff) + return -1; + switch (pkt->tprot) { case IPPROTO_TCP: *l4csum_offset = offsetof(struct tcphdr, check); -- 2.30.2