Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755633AbaLVSFi (ORCPT ); Mon, 22 Dec 2014 13:05:38 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:26439 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755111AbaLVSFh (ORCPT ); Mon, 22 Dec 2014 13:05:37 -0500 Message-ID: <54985D59.5010506@oracle.com> Date: Mon, 22 Dec 2014 13:05:13 -0500 From: Sasha Levin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: "Kirill A. Shutemov" , "david S. Miller" CC: "linux-mm@kvack.org" , LKML , Andrew Morton , Dave Jones , dave@stgolabs.net Subject: Re: mm: NULL ptr deref in unlink_file_vma References: <549832E2.8060609@oracle.com> <20141222180102.GA8072@node.dhcp.inet.fi> In-Reply-To: <20141222180102.GA8072@node.dhcp.inet.fi> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/22/2014 01:01 PM, Kirill A. Shutemov wrote: > On Mon, Dec 22, 2014 at 10:04:02AM -0500, Sasha Levin wrote: >> > Hi all, >> > >> > While fuzzing with trinity inside a KVM tools guest running the latest -next >> > kernel, I've stumbled on the following spew: >> > >> > [ 432.376425] BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 >> > [ 432.378876] IP: down_write (./arch/x86/include/asm/rwsem.h:105 ./arch/x86/include/asm/rwsem.h:121 kernel/locking/rwsem.c:71) > Looks like vma->vm_file->mapping is NULL. Somebody freed ->vm_file from > under us? > > I suspect Davidlohr's patchset on i_mmap_lock, but I cannot find any code > path which could lead to the crash. I've reported a different issue which that patchset: https://lkml.org/lkml/2014/12/9/741 I guess it could be related? Thanks, Sasha -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/