From patchwork Mon Jul 26 19:25:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 12400733 X-Patchwork-Delegate: kuba@kernel.org 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=-21.7 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 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 56280C4338F for ; Mon, 26 Jul 2021 19:22:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A8E760E08 for ; Mon, 26 Jul 2021 19:22:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231646AbhGZSmQ (ORCPT ); Mon, 26 Jul 2021 14:42:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:33268 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229593AbhGZSmP (ORCPT ); Mon, 26 Jul 2021 14:42:15 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BF3B660F6D; Mon, 26 Jul 2021 19:22:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1627327364; bh=GPp3eOsZSKAJOPnpQxw6ScV5mylXbFIUk8/qVauEq04=; h=Date:From:To:Cc:Subject:From; b=sRQJKN5+ZZ7b4hR/K333Ba3M6ic9UDQDg2eQV5d6mQmKk3gmhDUR16tZJsYcpchyz DEgFHNgFgrItMv6oJm6fa9yciQEgJwxL7/5z9lu75g9YgazCTu8oUp5oVfM1KIcxxd WV1ortnk1ktp03LG9/503rtEoFKkLSQHIcZXt8pHbuVwuNtIrMCJ42L49yTFbp2nPY JVKlhRvnTlBjDiZrHQ3NZgPzcOH7U3v6E1TXu7lCZ04s3Xw+NEss/RTPjrWPQ4BnSd 8iM4bHKaKx6ZkWf36Sz0vHEYfP2k45BRtEROXDy5F7WPuccgJormqbmwIUF7S1C9OL uuDB4feGyFw+g== Date: Mon, 26 Jul 2021 14:25:11 -0500 From: "Gustavo A. R. Silva" To: "David S. Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH][next] flow_dissector: Fix out-of-bounds warnings Message-ID: <20210726192511.GA23259@embeddedor> MIME-Version: 1.0 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Fix the following out-of-bounds warnings: net/core/flow_dissector.c: In function '__skb_flow_dissect': >> net/core/flow_dissector.c:1104:4: warning: 'memcpy' offset [24, 39] from the object at '' is out of the bounds of referenced subobject 'saddr' with type 'struct in6_addr' at offset 8 [-Warray-bounds] 1104 | memcpy(&key_addrs->v6addrs, &iph->saddr, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1105 | sizeof(key_addrs->v6addrs)); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from include/linux/ipv6.h:5, from net/core/flow_dissector.c:6: include/uapi/linux/ipv6.h:133:18: note: subobject 'saddr' declared here 133 | struct in6_addr saddr; | ^~~~~ >> net/core/flow_dissector.c:1059:4: warning: 'memcpy' offset [16, 19] from the object at '' is out of the bounds of referenced subobject 'saddr' with type 'unsigned int' at offset 12 [-Warray-bounds] 1059 | memcpy(&key_addrs->v4addrs, &iph->saddr, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1060 | sizeof(key_addrs->v4addrs)); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from include/linux/ip.h:17, from net/core/flow_dissector.c:5: include/uapi/linux/ip.h:103:9: note: subobject 'saddr' declared here 103 | __be32 saddr; | ^~~~~ 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(). So, the compiler legitimately complains about it. As these are just a couple of members, fix this by copying each one of them in separate calls to 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 --- net/core/flow_dissector.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 2aadbfc5193b..39d7be03e568 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -1056,8 +1056,10 @@ bool __skb_flow_dissect(const struct net *net, FLOW_DISSECTOR_KEY_IPV4_ADDRS, target_container); - memcpy(&key_addrs->v4addrs, &iph->saddr, - sizeof(key_addrs->v4addrs)); + memcpy(&key_addrs->v4addrs.src, &iph->saddr, + sizeof(key_addrs->v4addrs.src)); + memcpy(&key_addrs->v4addrs.dst, &iph->daddr, + sizeof(key_addrs->v4addrs.dst)); key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; } @@ -1101,8 +1103,10 @@ bool __skb_flow_dissect(const struct net *net, FLOW_DISSECTOR_KEY_IPV6_ADDRS, target_container); - memcpy(&key_addrs->v6addrs, &iph->saddr, - sizeof(key_addrs->v6addrs)); + memcpy(&key_addrs->v6addrs.src, &iph->saddr, + sizeof(key_addrs->v6addrs.src)); + memcpy(&key_addrs->v6addrs.dst, &iph->daddr, + sizeof(key_addrs->v6addrs.dst)); key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; }