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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 5C1AEC433E0 for ; Mon, 18 May 2020 17:44:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A795207C4 for ; Mon, 18 May 2020 17:44:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589823847; bh=55PKlhmg1rmfRguUkGNgpg1h9UfCnaM6roGxuu9k3bA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=O2mQFBWxJH7HtrjzxT9yPZzAI9U37KL1sEwdut84lzR4YnUB+xuCpybLopslDpghh hpUg/CKnxmL+DG8te+hiYTmo25pMFJcHcGPRRoextMw5HDmENqX6o0/M7ZqMtBSIRO fASuayUIGcrrtBRuy9d6O8ZCDC7yGWwJMnLF0Quk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729683AbgERRoG (ORCPT ); Mon, 18 May 2020 13:44:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:42032 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729650AbgERRoB (ORCPT ); Mon, 18 May 2020 13:44:01 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.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 43F52207C4; Mon, 18 May 2020 17:44:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589823840; bh=55PKlhmg1rmfRguUkGNgpg1h9UfCnaM6roGxuu9k3bA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MeHs8rx51KjpLOeGLfBxFioS3orUU6j2CSay1DozoCbChJywlgKCCmz9snO9MUwaF LfVXiL52tr45QpJW3xGzbZaiRnhd6hQlhBKlrmr0p0p3X0PCd/nY4RFa8PTdkCBxTt q+cAICmtfaFPawRxwTKaPo6LGXBT26BFuUyWaqAo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Arnd Bergmann , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 4.9 56/90] netfilter: conntrack: avoid gcc-10 zero-length-bounds warning Date: Mon, 18 May 2020 19:36:34 +0200 Message-Id: <20200518173502.512499313@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200518173450.930655662@linuxfoundation.org> References: <20200518173450.930655662@linuxfoundation.org> User-Agent: quilt/0.66 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 From: Arnd Bergmann [ Upstream commit 2c407aca64977ede9b9f35158e919773cae2082f ] gcc-10 warns around a suspicious access to an empty struct member: net/netfilter/nf_conntrack_core.c: In function '__nf_conntrack_alloc': net/netfilter/nf_conntrack_core.c:1522:9: warning: array subscript 0 is outside the bounds of an interior zero-length array 'u8[0]' {aka 'unsigned char[0]'} [-Wzero-length-bounds] 1522 | memset(&ct->__nfct_init_offset[0], 0, | ^~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from net/netfilter/nf_conntrack_core.c:37: include/net/netfilter/nf_conntrack.h:90:5: note: while referencing '__nfct_init_offset' 90 | u8 __nfct_init_offset[0]; | ^~~~~~~~~~~~~~~~~~ The code is correct but a bit unusual. Rework it slightly in a way that does not trigger the warning, using an empty struct instead of an empty array. There are probably more elegant ways to do this, but this is the smallest change. Fixes: c41884ce0562 ("netfilter: conntrack: avoid zeroing timer") Signed-off-by: Arnd Bergmann Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- include/net/netfilter/nf_conntrack.h | 2 +- net/netfilter/nf_conntrack_core.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h index b57a9f37c297b..7befec513295d 100644 --- a/include/net/netfilter/nf_conntrack.h +++ b/include/net/netfilter/nf_conntrack.h @@ -103,7 +103,7 @@ struct nf_conn { struct hlist_node nat_bysource; #endif /* all members below initialized via memset */ - u8 __nfct_init_offset[0]; + struct { } __nfct_init_offset; /* If we were expected by an expectation, this will be it */ struct nf_conn *master; diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 1bdae8f188e1f..d507d0fc7858a 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1124,9 +1124,9 @@ __nf_conntrack_alloc(struct net *net, *(unsigned long *)(&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev) = hash; ct->status = 0; write_pnet(&ct->ct_net, net); - memset(&ct->__nfct_init_offset[0], 0, + memset(&ct->__nfct_init_offset, 0, offsetof(struct nf_conn, proto) - - offsetof(struct nf_conn, __nfct_init_offset[0])); + offsetof(struct nf_conn, __nfct_init_offset)); nf_ct_zone_add(ct, zone); -- 2.20.1