From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <owner-linux-mm@kvack.org>
Received: from mail-wm0-f44.google.com (mail-wm0-f44.google.com [74.125.82.44])
	by kanga.kvack.org (Postfix) with ESMTP id 1D1976B0009
	for <linux-mm@kvack.org>; Thu, 28 Jan 2016 05:51:40 -0500 (EST)
Received: by mail-wm0-f44.google.com with SMTP id r129so18811631wmr.0
        for <linux-mm@kvack.org>; Thu, 28 Jan 2016 02:51:40 -0800 (PST)
Received: from mail-wm0-x234.google.com (mail-wm0-x234.google.com. [2a00:1450:400c:c09::234])
        by mx.google.com with ESMTPS id mn4si14625602wjc.49.2016.01.28.02.51.38
        for <linux-mm@kvack.org>
        (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);
        Thu, 28 Jan 2016 02:51:39 -0800 (PST)
Received: by mail-wm0-x234.google.com with SMTP id l66so19678858wml.0
        for <linux-mm@kvack.org>; Thu, 28 Jan 2016 02:51:38 -0800 (PST)
Date: Thu, 28 Jan 2016 12:51:36 +0200
From: "Kirill A. Shutemov" <kirill@shutemov.name>
Subject: Re: mm: another VM_BUG_ON_PAGE(PageTail(page))
Message-ID: <20160128105136.GD2396@node.shutemov.name>
References: <CACT4Y+Z9UDZNLsoEz-DO3fX_+0gTwPUA=uE++J=w1sAG_4CGJg@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CACT4Y+Z9UDZNLsoEz-DO3fX_+0gTwPUA=uE++J=w1sAG_4CGJg@mail.gmail.com>
Sender: owner-linux-mm@kvack.org
List-ID: <linux-mm.kvack.org>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>, Doug Gilbert <dgilbert@interlog.com>, Andrew Morton <akpm@linux-foundation.org>, David Rientjes <rientjes@google.com>, Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>, "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>, Shiraz Hashim <shashim@codeaurora.org>, "linux-mm@kvack.org" <linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>, Hugh Dickins <hughd@google.com>, Sasha Levin <sasha.levin@oracle.com>, syzkaller <syzkaller@googlegroups.com>, Kostya Serebryany <kcc@google.com>, Alexander Potapenko <glider@google.com>, linux-scsi <linux-scsi@vger.kernel.org>

On Thu, Jan 28, 2016 at 11:27:11AM +0100, Dmitry Vyukov wrote:
> Hello,
> 
> The following program triggers VM_BUG_ON_PAGE(PageTail(page)):
> 
> // autogenerated by syzkaller (http://github.com/google/syzkaller)
> #include <fcntl.h>
> #include <numaif.h>
> #include <sys/mman.h>
> #include <unistd.h>
> 
> int main()
> {
>   int fd;
> 
>   mmap((void*)0x20000000, 4096, PROT_READ|PROT_WRITE,
> MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
>   fd = open("/dev/sg1", O_RDONLY|O_SYNC|0x100000);
>   mmap((void*)0x20001000, 0x4000, PROT_READ|PROT_WRITE,
> MAP_PRIVATE|MAP_FIXED, fd, 0);
>   mbind((void*)0x20000000, 0x4000, 0x8002, (void*)0x20002ff8, 3660,
> MPOL_MF_STRICT|MPOL_MF_MOVE);
>   return 0;
> }

I don't have sg1 in my VM. I changed it to sg0 and it doesn't trigger an
issue: mbind() returns -EINVAL as it supposed to. Hm..

-- 
 Kirill A. Shutemov

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>