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=-8.6 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_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED, USER_AGENT_MUTT 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 E4520C10F0E for ; Mon, 15 Apr 2019 06:40:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A1C0A20833 for ; Mon, 15 Apr 2019 06:40:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="3DLm0Uga" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726195AbfDOGkX (ORCPT ); Mon, 15 Apr 2019 02:40:23 -0400 Received: from aserp2130.oracle.com ([141.146.126.79]:33862 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725796AbfDOGkX (ORCPT ); Mon, 15 Apr 2019 02:40:23 -0400 Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x3F6Y7vu146260; Mon, 15 Apr 2019 06:39:53 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 : content-transfer-encoding : in-reply-to; s=corp-2018-07-02; bh=XS+g3Z0HRLfU8/sWnJD7AQpQm56bAk9JHlxE4S9qN4M=; b=3DLm0UgaQF2zzfumrPrMGjRkHkdUI8vcWyFMEPRo8sShlgl4/nicB7oh6OBAPcrsjAnH TjTr8Je4wUKf/VQ+sdhlfeV2peyWwernWJ+uauoq1gxEWQCrgr5FM3whwFwZzM9vT3Md TbI6Fy0ND2v7oITGzl4Ik5r9mx6IkNqbq9urXUwArzTEVgmsztRrBSg1/JPGe5lT6U6K JGEIvR5jDRk7Sc02+IHmWeXnFB//69b3ZXHuVCPyTU65ljaL1w3OS9iVTJVJozCrqv45 VN+E9i575LFEXks3Z49ujJyjNCe+D0vpc65F+iBEypsoCa9jjJkUFSBatqDyQArX7fxt Zg== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by aserp2130.oracle.com with ESMTP id 2ru59cvu55-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 15 Apr 2019 06:39:53 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x3F6cLYB096181; Mon, 15 Apr 2019 06:39:53 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3020.oracle.com with ESMTP id 2rv2tu0m90-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 15 Apr 2019 06:39:52 +0000 Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x3F6dpcT022487; Mon, 15 Apr 2019 06:39:52 GMT Received: from kadam (/197.157.0.44) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Sun, 14 Apr 2019 23:39:50 -0700 Date: Mon, 15 Apr 2019 09:39:04 +0300 From: Dan Carpenter To: Vincent =?iso-8859-1?Q?Stehl=E9?= Cc: devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman Subject: Re: [PATCH] staging: android: vsoc: fix copy_from_user overrun Message-ID: <20190415063904.GH31633@kadam> References: <20190414153726.25362-1-vincent.stehle@laposte.net> <20190415063244.GM6095@kadam> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190415063244.GM6095@kadam> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9227 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=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904150044 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9227 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=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904150044 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 15, 2019 at 09:32:44AM +0300, Dan Carpenter wrote: > On Sun, Apr 14, 2019 at 05:37:26PM +0200, Vincent Stehlé wrote: > > The `np->permission' structure is smaller than the `np' structure but > > sizeof(*np) worth of data is copied in there. Fix the size passed to > > copy_from_user() to avoid overrun. > > > > Fixes: 3d2ec9dcd5539d42 ("staging: Android: Add 'vsoc' driver for cuttlefish.") > > Signed-off-by: Vincent Stehlé > > Cc: Greg Kroah-Hartman > > --- > > drivers/staging/android/vsoc.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/staging/android/vsoc.c b/drivers/staging/android/vsoc.c > > index 8a75bd27c4133..00a1ec7b91549 100644 > > --- a/drivers/staging/android/vsoc.c > > +++ b/drivers/staging/android/vsoc.c > > @@ -259,7 +259,8 @@ do_create_fd_scoped_permission(struct vsoc_device_region *region_p, > > atomic_t *owner_ptr = NULL; > > struct vsoc_device_region *managed_region_p; > > > > - if (copy_from_user(&np->permission, &arg->perm, sizeof(*np)) || > > + if (copy_from_user(&np->permission, > > + &arg->perm, sizeof(np->permission)) || > > The original code was probably correct... This is a common thing where > people use "&p->first_struct_member" to represent the whole struct. > It seems like kind of a horrible thing to do and I can't explain why > people do it, but they do... I have reviewed the code in a less totally lazy way and your patch is correct. Reviewed-by: Dan Carpenter The bug is harmless, though. We copy over the list pointers with user data and then immediately write the correct data to it. It should probably be a static checker warning when we copy to non __user tagged pointers. I think someone was adding this to Sparse but I should probably add it to Smatch as well. regards, dan carpenter