From patchwork Thu Sep 16 15:59:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 513697 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=-24.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 5103AC43219 for ; Thu, 16 Sep 2021 17:26:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36D4160F70 for ; Thu, 16 Sep 2021 17:26:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347294AbhIPR1w (ORCPT ); Thu, 16 Sep 2021 13:27:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:46946 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348325AbhIPRZz (ORCPT ); Thu, 16 Sep 2021 13:25:55 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3292D61C11; Thu, 16 Sep 2021 16:44:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631810668; bh=SRdQCPEwZvVgjGZFCEs93cZmMKILet+Vok/yBQz6qTg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZoSmpCxMbkmigGsZxPPz7ocI3GGSTtKcfWGdbQSw/5a7d5wEC2bSScgtLPqABfVAN AURpsqYiqekoA61YhpWnMMU1NfPVWGRmfCRQwNtTFnN6qXBY71ul2JZnLxbl06Heel xANKmkkXVu6qjx18w6z9HCy6pmRbULSIZ/MBZks0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, kernel test robot , "Gustavo A. R. Silva" , "David S. Miller" , Sasha Levin Subject: [PATCH 5.14 225/432] ipv4: ip_output.c: Fix out-of-bounds warning in ip_copy_addrs() Date: Thu, 16 Sep 2021 17:59:34 +0200 Message-Id: <20210916155818.469713068@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210916155810.813340753@linuxfoundation.org> References: <20210916155810.813340753@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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 8d8a8da3ae7e..a202dcec0dc2 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -446,8 +446,9 @@ 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 */