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=-8.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,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 88843C65C22 for ; Fri, 2 Nov 2018 18:39:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 55C6F20837 for ; Fri, 2 Nov 2018 18:39:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="B8sww7uC" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 55C6F20837 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729213AbeKCDrx (ORCPT ); Fri, 2 Nov 2018 23:47:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:42076 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729198AbeKCDrx (ORCPT ); Fri, 2 Nov 2018 23:47:53 -0400 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 038732082E; Fri, 2 Nov 2018 18:39:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541183981; bh=+FiNWyYf+rWcL2H52QxCfIoU/t7oH4HWlvEJrDjvMCU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B8sww7uCVP3YYIDpuk32LNjl9Epirlk2j9TqyU+YbJgnGTbdYTmqtTZmRbG3nR0cW ZxpelAsz0png0fNtFuXtit8hWRRMgV+ZbrDTWM77AyRjkYtCcI/apaGloswHptwVV4 mP2O+pGAjJ2ZRk3hVTo3IxgC+gWxFcwDb0FCx+UE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Ahern , Florian Westphal , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 4.18 041/150] netfilter: avoid erronous array bounds warning Date: Fri, 2 Nov 2018 19:33:23 +0100 Message-Id: <20181102182906.232620214@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181102182902.250560510@linuxfoundation.org> References: <20181102182902.250560510@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 421c119f558761556afca6a62ad183bc2d8659e0 ] Unfortunately some versions of gcc emit following warning: $ make net/xfrm/xfrm_output.o linux/compiler.h:252:20: warning: array subscript is above array bounds [-Warray-bounds] hook_head = rcu_dereference(net->nf.hooks_arp[hook]); ^~~~~~~~~~~~~~~~~~~~~ xfrm_output_resume passes skb_dst(skb)->ops->family as its 'pf' arg so compiler can't know that we'll never access hooks_arp[]. (NFPROTO_IPV4 or NFPROTO_IPV6 are only possible cases). Avoid this by adding an explicit WARN_ON_ONCE() check. This patch has no effect if the family is a compile-time constant as gcc will remove the switch() construct entirely. Reported-by: David Ahern Signed-off-by: Florian Westphal Reviewed-by: David Ahern Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- include/linux/netfilter.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h index dd2052f0efb7..11b7b8ab0696 100644 --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -215,6 +215,8 @@ static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net, break; case NFPROTO_ARP: #ifdef CONFIG_NETFILTER_FAMILY_ARP + if (WARN_ON_ONCE(hook >= ARRAY_SIZE(net->nf.hooks_arp))) + break; hook_head = rcu_dereference(net->nf.hooks_arp[hook]); #endif break; -- 2.17.1