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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 A7F86C32788 for ; Thu, 11 Oct 2018 15:37:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6F1152087A for ; Thu, 11 Oct 2018 15:37:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="xS6xSI86" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6F1152087A 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 S1729191AbeJKXEo (ORCPT ); Thu, 11 Oct 2018 19:04:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:60202 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728128AbeJKXEn (ORCPT ); Thu, 11 Oct 2018 19:04:43 -0400 Received: from localhost (ip-213-127-77-176.ip.prioritytelecom.net [213.127.77.176]) (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 DB2DC2147C; Thu, 11 Oct 2018 15:37:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539272221; bh=NnIhdksCZqb+Dr0vRIBAIQxeKv0A+Ofxed59dCAsiy4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xS6xSI86seIoF+OfHt76EBJ1SS2vdPnq/rQZnVxG0caavTLJB855dPyF+0jdjNWq5 2ZGtd9uFJFxA3dglQyFuP7HmLT1V++mJmmDXyVCOeTBwP68T47as2ZSyNbBJvhmGxO 6lKk95DCDfiAADe8p9/AewlQ6mvMU6EzWKZUOAa4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Heiko Carstens , Vasily Gorbik , Martin Schwidefsky , Sasha Levin Subject: [PATCH 3.18 032/120] s390/extmem: fix gcc 8 stringop-overflow warning Date: Thu, 11 Oct 2018 17:33:33 +0200 Message-Id: <20181011152550.998527629@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181011152549.500488630@linuxfoundation.org> References: <20181011152549.500488630@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 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vasily Gorbik [ Upstream commit 6b2ddf33baec23dace85bd647e3fc4ac070963e8 ] arch/s390/mm/extmem.c: In function '__segment_load': arch/s390/mm/extmem.c:436:2: warning: 'strncat' specified bound 7 equals source length [-Wstringop-overflow=] strncat(seg->res_name, " (DCSS)", 7); What gcc complains about here is the misuse of strncat function, which in this case does not limit a number of bytes taken from "src", so it is in the end the same as strcat(seg->res_name, " (DCSS)"); Keeping in mind that a res_name is 15 bytes, strncat in this case would overflow the buffer and write 0 into alignment byte between the fields in the struct. To avoid that increasing res_name size to 16, and reusing strlcat. Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/s390/mm/extmem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/s390/mm/extmem.c +++ b/arch/s390/mm/extmem.c @@ -80,7 +80,7 @@ struct qin64 { struct dcss_segment { struct list_head list; char dcss_name[8]; - char res_name[15]; + char res_name[16]; unsigned long start_addr; unsigned long end; atomic_t ref_count; @@ -445,7 +445,7 @@ __segment_load (char *name, int do_nonsh memcpy(&seg->res_name, seg->dcss_name, 8); EBCASC(seg->res_name, 8); seg->res_name[8] = '\0'; - strncat(seg->res_name, " (DCSS)", 7); + strlcat(seg->res_name, " (DCSS)", sizeof(seg->res_name)); seg->res->name = seg->res_name; rc = seg->vm_segtype; if (rc == SEG_TYPE_SC ||