From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-la0-f48.google.com (mail-la0-f48.google.com [209.85.215.48]) by kanga.kvack.org (Postfix) with ESMTP id 64B026B0253 for ; Tue, 22 Sep 2015 12:47:18 -0400 (EDT) Received: by lagj9 with SMTP id j9so20260479lag.2 for ; Tue, 22 Sep 2015 09:47:17 -0700 (PDT) Received: from mail-la0-x22a.google.com (mail-la0-x22a.google.com. [2a00:1450:4010:c03::22a]) by mx.google.com with ESMTPS id o64si840978lfe.117.2015.09.22.09.47.17 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 22 Sep 2015 09:47:17 -0700 (PDT) Received: by lagj9 with SMTP id j9so20260048lag.2 for ; Tue, 22 Sep 2015 09:47:17 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20150915190143.GA18670@node.dhcp.inet.fi> References: <55EC9221.4040603@oracle.com> <20150907114048.GA5016@node.dhcp.inet.fi> <55F0D5B2.2090205@oracle.com> <20150910083605.GB9526@node.dhcp.inet.fi> <20150911103959.GA7976@node.dhcp.inet.fi> <55F8572D.8010409@oracle.com> <20150915190143.GA18670@node.dhcp.inet.fi> Date: Tue, 22 Sep 2015 18:47:16 +0200 Message-ID: Subject: Re: Multiple potential races on vma->vm_flags From: Andrey Konovalov Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: Sasha Levin , Hugh Dickins , Oleg Nesterov , Rik van Riel , Andrew Morton , Dmitry Vyukov , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vlastimil Babka If anybody comes up with a patch to fix the original issue I easily can test it, since I'm hitting "BUG: Bad page state" in a second when fuzzing with KTSAN and Trinity. On Tue, Sep 15, 2015 at 9:01 PM, Kirill A. Shutemov wrote: > On Tue, Sep 15, 2015 at 01:36:45PM -0400, Sasha Levin wrote: >> On 09/11/2015 09:27 PM, Hugh Dickins wrote: >> > I'm inclined to echo Vlastimil's comment from earlier in the thread: >> > sounds like an overkill, unless we find something more serious than this. >> >> I've modified my tests to stress the exit path of processes with many vmas, > > Could you share the test? > >> and hit the following NULL ptr deref (not sure if it's related to the original issue): >> >> [1181047.935563] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN >> [1181047.937223] Modules linked in: >> [1181047.937772] CPU: 4 PID: 21912 Comm: trinity-c341 Not tainted 4.3.0-rc1-next-20150914-sasha-00043-geddd763-dirty #2554 >> [1181047.939387] task: ffff8804195c8000 ti: ffff880433f00000 task.ti: ffff880433f00000 >> [1181047.940533] RIP: unmap_vmas (mm/memory.c:1337) > > Is it "struct mm_struct *mm = vma->vm_mm;"? > > -- > 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: email@kvack.org