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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, USER_AGENT_SANE_1 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 B7077CA9EA0 for ; Mon, 28 Oct 2019 07:21:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A2DE20862 for ; Mon, 28 Oct 2019 07:21:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="QZ3mFo4d" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732761AbfJ1HVr (ORCPT ); Mon, 28 Oct 2019 03:21:47 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:44484 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730346AbfJ1HVr (ORCPT ); Mon, 28 Oct 2019 03:21:47 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x9S7JGF8158431; Mon, 28 Oct 2019 07:21:31 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2019-08-05; bh=6UrEt8Yob0WvnmAEmegBqErzZ/vNf8vt6/tp3mnw1QE=; b=QZ3mFo4dfKxKWOxUf6tINRvNo006Y5lDeMmbZsbVUFo7aYrvSdpBSJY2p8gki1dfWCvF k7QB2fwdMVRYpGzKuGUDYuxfsuS1kav/Mln3nN6gymXwknafBlsx7b37p6AvDvHHBO7f T2t9cuDpnbUYBQLN8CmI2OLiTf5EW0rLDDBAhNCg0O4ImO0MzJopRn1qaSssxkt2zv0U 6A0gwzsPllysVcXgprVZdlfrJEpLvodyZQdcxx9YTrA+heH6bSwppYquJDdtLss1NXNj 6Kv1sS7i7T9HtsDg7xfZuoQWgWMTPc+a4HE4dB6R8/94IUSqxrQLMzB2czwEml7yRnBh qQ== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by aserp2120.oracle.com with ESMTP id 2vve3pyyjn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 28 Oct 2019 07:21:31 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x9S7JSsE168600; Mon, 28 Oct 2019 07:19:30 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3030.oracle.com with ESMTP id 2vwakxgjfd-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 28 Oct 2019 07:19:30 +0000 Received: from abhmp0018.oracle.com (abhmp0018.oracle.com [141.146.116.24]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x9S7J2ZJ004438; Mon, 28 Oct 2019 07:19:04 GMT Received: from kadam (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 28 Oct 2019 00:19:02 -0700 Date: Mon, 28 Oct 2019 10:18:56 +0300 From: Dan Carpenter To: Joe Perches Cc: Andrew Morton , LKML , Dan Carpenter , Julia Lawall , Thomas Gleixner Subject: Re: [PATCH] kernel: sys.c: Avoid copying possible padding bytes in copy_to_user Message-ID: <20191028071856.GA1944@kadam> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9423 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=884 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910280073 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9423 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=964 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910280073 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Oct 26, 2019 at 12:46:08PM -0700, Joe Perches wrote: > Initialization is not guaranteed to zero padding bytes so > use an explicit memset instead to avoid leaking any kernel > content in any possible padding bytes. > > Signed-off-by: Joe Perches > --- > kernel/sys.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/kernel/sys.c b/kernel/sys.c > index a611d1..3459a5 100644 > --- a/kernel/sys.c > +++ b/kernel/sys.c > @@ -1279,11 +1279,13 @@ SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) > > SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) > { > - struct oldold_utsname tmp = {}; > + struct oldold_utsname tmp; oldold_utsname doesn't have an struct holes. It looks like this: struct oldold_utsname { char sysname[9]; char nodename[9]; char release[9]; char version[9]; char machine[9]; }; regards, dan carpenter