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,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 D2CC7C677FC for ; Thu, 11 Oct 2018 15:39:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 96E6E20652 for ; Thu, 11 Oct 2018 15:39:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="P+c65w6z" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 96E6E20652 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 S1729958AbeJKXHS (ORCPT ); Thu, 11 Oct 2018 19:07:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:36858 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726721AbeJKXHQ (ORCPT ); Thu, 11 Oct 2018 19:07:16 -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 5D59B20652; Thu, 11 Oct 2018 15:39:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539272372; bh=7AUD/o2vwNYLEdpINF4fQS/uh4nfSrOoBgqHXfW+JCs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P+c65w6zBSFPGsLBhvgeZ99r1gbuHnOPBCJa6BkkchXQv/JwNVL6MdT9W6/S0w/k3 ZLbefU2B/f37vz9djtwLTh0EG0LzyGxkeG5ocn7GTvTB548JHuxeWftvAx9th+AsLZ +/UEWjDuJxXYUysOQgtM/u/fANJDHsyDEWZh3Nis= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stephen Rothwell , Steve French , Sasha Levin Subject: [PATCH 3.18 086/120] fs/cifs: suppress a string overflow warning Date: Thu, 11 Oct 2018 17:34:27 +0200 Message-Id: <20181011152553.373014019@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: Stephen Rothwell [ Upstream commit bcfb84a996f6fa90b5e6e2954b2accb7a4711097 ] A powerpc build of cifs with gcc v8.2.0 produces this warning: fs/cifs/cifssmb.c: In function ‘CIFSSMBNegotiate’: fs/cifs/cifssmb.c:605:3: warning: ‘strncpy’ writing 16 bytes into a region of size 1 overflows the destination [-Wstringop-overflow=] strncpy(pSMB->DialectsArray+count, protocols[i].name, 16); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Since we are already doing a strlen() on the source, change the strncpy to a memcpy(). Signed-off-by: Stephen Rothwell Signed-off-by: Steve French Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/cifs/cifssmb.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -577,10 +577,15 @@ CIFSSMBNegotiate(const unsigned int xid, } count = 0; + /* + * We know that all the name entries in the protocols array + * are short (< 16 bytes anyway) and are NUL terminated. + */ for (i = 0; i < CIFS_NUM_PROT; i++) { - strncpy(pSMB->DialectsArray+count, protocols[i].name, 16); - count += strlen(protocols[i].name) + 1; - /* null at end of source and target buffers anyway */ + size_t len = strlen(protocols[i].name) + 1; + + memcpy(pSMB->DialectsArray+count, protocols[i].name, len); + count += len; } inc_rfc1001_len(pSMB, count); pSMB->ByteCount = cpu_to_le16(count);