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=-24.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 47B40C433EF for ; Thu, 9 Sep 2021 13:25:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26D6A610E8 for ; Thu, 9 Sep 2021 13:25:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353108AbhIINYC (ORCPT ); Thu, 9 Sep 2021 09:24:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:53480 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358416AbhIINHT (ORCPT ); Thu, 9 Sep 2021 09:07:19 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 14864632AC; Thu, 9 Sep 2021 12:00:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631188838; bh=6woaAJNYbapAVX7efnvWQUPnidQjrilw2Bey6M517to=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BF53y2EXloYBJvGtZBkxYmbkafyTKZsNLZc0NdWwWaXgF9b/r5QPCKFo3OSTB9Luz rkkrZegLfqEU012P7oh8OF+fWyG3p0ROmfrxnmRyVhOUYI6J4dp2FHWd8QxmSlqgvw JqT4fllHLx8HbQebl4KVSJoHQDsIY5GQCOHriYrEjkhvhdfM6p6vI/3wUKl76SwsCM XoKWAnFLvNy2NT7otPhf+9N1rLd6S0XmGJ1gK9gilidLpSNkLNeG6v+3C/zgX3LQPo AgwWx87RggR0ESPuNVXyxuz0Og3SOQfBdZIpSF3kb8s1+7SB5mcB47avdkwaaVKayN UP2R0z74dRTWg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Gustavo A. R. Silva" , kernel test robot , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 18/48] ipv4: ip_output.c: Fix out-of-bounds warning in ip_copy_addrs() Date: Thu, 9 Sep 2021 07:59:45 -0400 Message-Id: <20210909120015.150411-18-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210909120015.150411-1-sashal@kernel.org> References: <20210909120015.150411-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Gustavo A. R. Silva" [ Upstream commit 6321c7acb82872ef6576c520b0e178eaad3a25c0 ] Fix the following out-of-bounds warning: In function 'ip_copy_addrs', inlined from '__ip_queue_xmit' at net/ipv4/ip_output.c:517:2: net/ipv4/ip_output.c:449:2: warning: 'memcpy' offset [40, 43] from the object at 'fl' is out of the bounds of referenced subobject 'saddr' with type 'unsigned int' at offset 36 [-Warray-bounds] 449 | memcpy(&iph->saddr, &fl4->saddr, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 450 | sizeof(fl4->saddr) + sizeof(fl4->daddr)); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The problem is that the original code is trying to copy data into a couple of struct members adjacent to each other in a single call to memcpy(). This causes a legitimate compiler warning because memcpy() overruns the length of &iph->saddr and &fl4->saddr. As these are just a couple of struct members, fix this by using direct assignments, instead of memcpy(). This helps with the ongoing efforts to globally enable -Warray-bounds and get us closer to being able to tighten the FORTIFY_SOURCE routines on memcpy(). Link: https://github.com/KSPP/linux/issues/109 Reported-by: kernel test robot Link: https://lore.kernel.org/lkml/d5ae2e65-1f18-2577-246f-bada7eee6ccd@intel.com/ Signed-off-by: Gustavo A. R. Silva Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/ip_output.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 3164bae4024a..589fd0904e0d 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -393,8 +393,9 @@ static void ip_copy_addrs(struct iphdr *iph, const struct flowi4 *fl4) { BUILD_BUG_ON(offsetof(typeof(*fl4), daddr) != offsetof(typeof(*fl4), saddr) + sizeof(fl4->saddr)); - memcpy(&iph->saddr, &fl4->saddr, - sizeof(fl4->saddr) + sizeof(fl4->daddr)); + + iph->saddr = fl4->saddr; + iph->daddr = fl4->daddr; } /* Note: skb->sk can be different from sk, in case of tunnels */ -- 2.30.2