From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752403AbdLDLXF (ORCPT ); Mon, 4 Dec 2017 06:23:05 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:33107 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751156AbdLDLXD (ORCPT ); Mon, 4 Dec 2017 06:23:03 -0500 X-Greylist: delayed 11307 seconds by postgrey-1.27 at vger.kernel.org; Mon, 04 Dec 2017 06:23:02 EST Date: Mon, 4 Dec 2017 11:14:08 +0300 From: Dan Carpenter To: Eric Biggers Cc: syzbot , adobriyan@gmail.com, akpm@linux-foundation.org, arnd@arndb.de, dave.jiang@intel.com, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk, linux-block@vger.kernel.org Subject: Re: WARNING in kmalloc_slab (3) Message-ID: <20171204081408.oyp46roxbkjbxxkw@mwanda> References: <20171203201608.GC844@zzz.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171203201608.GC844@zzz.localdomain> User-Agent: NeoMutt/20170609 (1.8.3) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8734 signatures=668637 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1712040120 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Dec 03, 2017 at 12:16:08PM -0800, Eric Biggers wrote: > Looks like BLKTRACESETUP doesn't limit the '.buf_nr' parameter, allowing anyone > who can open a block device to cause an extremely large kmalloc. Here's a > simplified reproducer: > There are lots of places which allow people to allocate as much as they want. With Syzcaller, you might want to just hard code a __GFP_NOWARN in to disable it. regards, dan carpenter