From patchwork Thu Jul 23 15:23:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Carpenter X-Patchwork-Id: 11681215 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7A1FD138C for ; Thu, 23 Jul 2020 15:25:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 558D7206D8 for ; Thu, 23 Jul 2020 15:25:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="Us6llAZP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727108AbgGWPZy (ORCPT ); Thu, 23 Jul 2020 11:25:54 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:54170 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725843AbgGWPZy (ORCPT ); Thu, 23 Jul 2020 11:25:54 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 06NFMs2N080032; Thu, 23 Jul 2020 15:25:47 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=ih7aDDHndvJgRh9w5b+olJvrbDWUkyFxJDMc04b3AcE=; b=Us6llAZPwqKXRXoeLVi15UBQwyZu62gUGDF8yz+IhYoYjCJAo9df4dw52U4kwHg5KNyc nkWqL5sRX8LfAUTo/OczU/BJLh9T8MsDS2XKUFc3YEnxJ/XkknjhIvg7brUXWMFE4PUv XYhL6nY8L/DCwxlXSOHBR9u6diXU+BmYSlowasnIqQFhbIAxyG+rvLueSTLWZxgcU1xT z9y/1YLlKdeyGm7nPhV/KSkgIRYD8WTUx+pOnJuYO4DkrhjQDrCTRN1sn66vyVkQi6qs XDFnb1cAGcjtL58euLOZzKv6Z51jGq0KOQfL2cECGXvIwFRj60YEu+Qb0mVtxyJjsd/D Zw== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2130.oracle.com with ESMTP id 32brgrt3ab-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 23 Jul 2020 15:25:47 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 06NFNh2O000842; Thu, 23 Jul 2020 15:23:46 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3030.oracle.com with ESMTP id 32fb8gysps-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 23 Jul 2020 15:23:46 +0000 Received: from abhmp0010.oracle.com (abhmp0010.oracle.com [141.146.116.16]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 06NFNC5a004638; Thu, 23 Jul 2020 15:23:12 GMT Received: from mwanda (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 23 Jul 2020 08:23:11 -0700 Date: Thu, 23 Jul 2020 18:23:05 +0300 From: Dan Carpenter To: Casey Schaufler Cc: James Morris , "Serge E. Hallyn" , Andrew Morton , linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: [PATCH 2/2] Smack: prevent underflow in smk_set_cipso() Message-ID: <20200723152305.GB302005@mwanda> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <000000000000d282bd05ab0bf532@google.com> X-Mailer: git-send-email haha only kidding X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9691 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 mlxlogscore=968 bulkscore=0 malwarescore=0 mlxscore=0 spamscore=0 phishscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007230115 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9691 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 bulkscore=0 spamscore=0 impostorscore=0 suspectscore=0 adultscore=0 clxscore=1015 mlxlogscore=975 priorityscore=1501 phishscore=0 lowpriorityscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007230115 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: We have an upper bound on "maplevel" but forgot to check for negative values. Fixes: e114e473771c ("Smack: Simplified Mandatory Access Control Kernel") Signed-off-by: Dan Carpenter --- security/smack/smackfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index 81c6ceeaa4f9..7675305511ef 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -884,7 +884,7 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf, } ret = sscanf(rule, "%d", &maplevel); - if (ret != 1 || maplevel > SMACK_CIPSO_MAXLEVEL) + if (ret != 1 || maplevel < 0 || maplevel > SMACK_CIPSO_MAXLEVEL) goto out; rule += SMK_DIGITLEN;