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 X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ADC22C4320E for ; Mon, 30 Aug 2021 09:16:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8FE3A6103C for ; Mon, 30 Aug 2021 09:16:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235367AbhH3JRu (ORCPT ); Mon, 30 Aug 2021 05:17:50 -0400 Received: from out1.migadu.com ([91.121.223.63]:16849 "EHLO out1.migadu.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235042AbhH3JRt (ORCPT ); Mon, 30 Aug 2021 05:17:49 -0400 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1630315014; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=RnZU/eiz4GTpQlhOPHQMTWd/YBLjcRvYkWNaDFjlT3A=; b=VnMxU5RoF+peuR8YKJyyKmseBGFc2tMlgVknNtQfxcdL35EElLiQ6HuwsDnEYucS9SfTrq DN56XFvLbhnpnYSJcaZUGLhysScqHkKHFCQzhCPNWvaQEKAXccyxYVxCA8AD23HoZAcynF 8/tUBZjRzov70oVngtpWi2lGKbLmFCE= From: Yajun Deng To: davem@davemloft.net, yoshfuji@linux-ipv6.org, dsahern@kernel.org, kuba@kernel.org Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Yajun Deng , Dan Carpenter Subject: [PATCH net-next] net: ipv4: Fix the warning for dereference Date: Mon, 30 Aug 2021 17:16:40 +0800 Message-Id: <20210830091640.14739-1-yajun.deng@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: yajun.deng@linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a if statements to avoid the warning. Dan Carpenter report: The patch faf482ca196a: "net: ipv4: Move ip_options_fragment() out of loop" from Aug 23, 2021, leads to the following Smatch complaint: net/ipv4/ip_output.c:833 ip_do_fragment() warn: variable dereferenced before check 'iter.frag' (see line 828) Reported-by: Dan Carpenter Fixes: faf482ca196a ("net: ipv4: Move ip_options_fragment() out of loop") Link: https://lore.kernel.org/netdev/20210830073802.GR7722@kadam/T/#t Signed-off-by: Yajun Deng --- net/ipv4/ip_output.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 9a8f05d5476e..9bca57ef8b83 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -825,7 +825,9 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, /* Everything is OK. Generate! */ ip_fraglist_init(skb, iph, hlen, &iter); - ip_options_fragment(iter.frag); + + if (iter.frag) + ip_options_fragment(iter.frag); for (;;) { /* Prepare header of the next frame, -- 2.32.0