From patchwork Fri Apr 16 19:31:51 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: 12208661 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=-21.0 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 6AA4DC433B4 for ; Fri, 16 Apr 2021 19:31:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3EF4660FF1 for ; Fri, 16 Apr 2021 19:31:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243493AbhDPTcG (ORCPT ); Fri, 16 Apr 2021 15:32:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:34688 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231510AbhDPTcE (ORCPT ); Fri, 16 Apr 2021 15:32:04 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 123CE611AB; Fri, 16 Apr 2021 19:31:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618601499; bh=8LNu5JOmFuLKWCjhg6+ayA0INbjk1fmtkW1OrPWr+Os=; h=Date:From:To:Cc:Subject:From; b=vIgrnyPgyyP3Dnnu1GZGQWUmQ3qTzbLx+61BK6VWmsBilTmeF6jbPUrq4UC85nAL9 kTYW/2xQzfnnf3dP5iw/r8oaxsFNPmV1eowFR53qnELNza9h6548PMCpTCSS2BM5pS ImM2wrKFBC+07nATJOUFURB8cdcsoavq+gMGHJBnWisb1V7YDvcR/T/S8Fbpxeosvo gv5HAW1KJomao7bPzxZBqaTmLxphzMgO3MiGG/a2Uir4WzQnnnS7smG+tq4FBKMyUz 48D1gRIr2gnCOBLKJi/bqHhjmsZI514jYNc7bRb40nuTIf699NUp1ppYX3aoZBE5vo CDDqefV2OD2zA== Date: Fri, 16 Apr 2021 14:31:51 -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 warning in __skb_flow_bpf_to_target() Message-ID: <20210416193151.GA591935@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 warning: net/core/flow_dissector.c:835:3: warning: 'memcpy' offset [33, 48] from the object at 'flow_keys' is out of the bounds of referenced subobject 'ipv6_src' with type '__u32[4]' {aka 'unsigned int[4]'} at offset 16 [-Warray-bounds] 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 Signed-off-by: Gustavo A. R. Silva --- net/core/flow_dissector.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 5985029e43d4..3ed7c98a98e1 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -832,8 +832,10 @@ static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys, key_addrs = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_IPV6_ADDRS, target_container); - memcpy(&key_addrs->v6addrs, &flow_keys->ipv6_src, - sizeof(key_addrs->v6addrs)); + memcpy(&key_addrs->v6addrs.src, &flow_keys->ipv6_src, + sizeof(key_addrs->v6addrs.src)); + memcpy(&key_addrs->v6addrs.dst, &flow_keys->ipv6_dst, + sizeof(key_addrs->v6addrs.dst)); key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; }