From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f69.google.com (mail-pl0-f69.google.com [209.85.160.69]) by kanga.kvack.org (Postfix) with ESMTP id ACCE46B000D for ; Wed, 11 Jul 2018 17:04:51 -0400 (EDT) Received: by mail-pl0-f69.google.com with SMTP id y2-v6so5809410pll.16 for ; Wed, 11 Jul 2018 14:04:51 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id y17-v6si18997190plp.219.2018.07.11.14.04.50 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 11 Jul 2018 14:04:50 -0700 (PDT) Date: Wed, 11 Jul 2018 14:04:49 -0700 From: Andrew Morton Subject: Re: general protection fault in _vm_normal_page Message-Id: <20180711140449.3702358d7e8898017e34dcfd@linux-foundation.org> In-Reply-To: <00000000000010c9390570bc0643@google.com> References: <00000000000010c9390570bc0643@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: syzbot Cc: jglisse@redhat.com, kirill.shutemov@linux.intel.com, ldufour@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.com, minchan@kernel.org, ross.zwisler@linux.intel.com, sfr@canb.auug.org.au, syzkaller-bugs@googlegroups.com, ying.huang@intel.com On Wed, 11 Jul 2018 09:49:01 -0700 syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 98be45067040 Add linux-next specific files for 20180711 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=12496ac2400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=3f3b3673fec35d01 > dashboard link: https://syzkaller.appspot.com/bug?extid=120abb1c3f7bfdc523f7 > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=12a46568400000 Handy. /dev/ion from drivers/staging/android/ion/ion.c > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+120abb1c3f7bfdc523f7@syzkaller.appspotmail.com > > R10: 0000000004000812 R11: 0000000000000246 R12: 0000000000000005 > R13: 00000000004c0565 R14: 00000000004cffb0 R15: 0000000000000005 > ion_mmap: failure mapping buffer to userspace > kasan: CONFIG_KASAN_INLINE enabled > kasan: GPF could be caused by NULL-ptr deref or user memory access > general protection fault: 0000 [#1] SMP KASAN > CPU: 0 PID: 4785 Comm: syz-executor0 Not tainted 4.18.0-rc4-next-20180711+ > #4 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:_vm_normal_page+0x1e5/0x330 mm/memory.c:828 Presumably has a NULL vma->vm_ops. Probably one of the now-removed checks in mm-drop-unneeded-vm_ops-checks.patch would have avoided this. Something for Kirill to think about ;)