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From: Dmitry Vyukov <dvyukov@google.com>
Date: Mon, 11 Apr 2016 11:03:01 +0200
Message-ID: <CACT4Y+ZZ_SJ=qiqWLu4NgeOUdiQPH_YvWXS5cn03uLkFU9R8Lg@mail.gmail.com>
Subject: Re: x86: bad pte in pageattr_test
To: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>, "x86@kernel.org" <x86@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Konstantin Khlebnikov <koct9i@gmail.com>,
        syzkaller <syzkaller@googlegroups.com>,
        Kostya Serebryany <kcc@google.com>,
        Alexander Potapenko <glider@google.com>,
        Sasha Levin <sasha.levin@oracle.com>
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On Mon, Apr 11, 2016 at 10:52 AM, Andrey Ryabinin
<ryabinin.a.a@gmail.com> wrote:
>
>
> On 04/11/2016 11:28 AM, Dmitry Vyukov wrote:
>> Hello,
>>
>> I've got the following WARNING while running syzkaller fuzzer:
>>
>> CPA ffff880054118000: bad pte after revert 8000000054118363
>> ------------[ cut here ]------------
>> WARNING: CPU: 2 PID: 1503 at arch/x86/mm/pageattr-test.c:226
>> pageattr_test+0xa6c/0xd10
>> NOT PASSED. Please report.
>> Modules linked in:
>> CPU: 2 PID: 1503 Comm: pageattr-test Not tainted 4.6.0-rc2+ #346
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>>  ffffffff87eb25c0 ffff88003b627a70 ffffffff82c8b17f ffffffff81490b58
>>  fffffbfff0fd64b8 ffff88003b627ae8 0000000000000000 ffffffff86a77e00
>>  ffffffff8129487c 0000000000000009 ffff88003b627ab8 ffffffff8136639f
>> Call Trace:
>>  [<     inline     >] __dump_stack lib/dump_stack.c:15
>>  [<ffffffff82c8b17f>] dump_stack+0x12e/0x18f lib/dump_stack.c:51
>>  [<ffffffff8136639f>] __warn+0x19f/0x1e0 kernel/panic.c:512
>>  [<ffffffff8136648c>] warn_slowpath_fmt+0xac/0xd0 kernel/panic.c:527
>>  [<ffffffff8129487c>] pageattr_test+0xa6c/0xd10 arch/x86/mm/pageattr-test.c:226
>>  [<ffffffff81294b3b>] do_pageattr_test+0x1b/0x60 arch/x86/mm/pageattr-test.c:240
>>  [<ffffffff813cde7f>] kthread+0x23f/0x2d0 drivers/block/aoe/aoecmd.c:1303
>
> It seems, that your script is buggy. It should be kthread() from kernel/kthread.c here.


I probably used a non-matching vmlinux for symbolization.  Please
check the raw report below if the symbolized one does not make sense.

\/\/\/\/\/\/\/\/

>> For the repcord, full syzkaller log:
>> https://gist.githubusercontent.com/dvyukov/323ff7275c5ac38156cb40caeacac057/raw/0836f8dd81024e441f81caebdcb73ca1221aef97/gistfile1.txt