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From: Dmitry Vyukov <dvyukov@google.com>
Date: Tue, 7 Jun 2016 11:34:01 +0200
Message-ID: <CACT4Y+ZTFGqVjokXUefFMJOrhAn+go3hPKvQRdAhgRRhab5GrQ@mail.gmail.com>
Subject: Re: x86: bad pte in pageattr_test
To: 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>,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        Konstantin Khlebnikov <koct9i@gmail.com>
Cc: 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 10:28 AM, Dmitry Vyukov <dvyukov@google.com> 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
>  [<ffffffff867b6252>] ret_from_fork+0x22/0x50 arch/x86/entry/entry_64.S:392
> ---[ end trace e669a8d69b836be8 ]---
>
> Unfortunately it is not reproducible, tried bumping checking frequency to 1.
>
> On commit 541d8f4d59d79f5d37c8c726f723d42ff307db57 (Apr 5).
>
> For the repcord, full syzkaller log:
> https://gist.githubusercontent.com/dvyukov/323ff7275c5ac38156cb40caeacac057/raw/0836f8dd81024e441f81caebdcb73ca1221aef97/gistfile1.txt


Ping.

Hit it again on af8c34ce6ae32addda3788d54a7e340cad22516b (4.7-rc2)

CPA ffff880059990000: bad pte 8000000059990060
------------[ cut here ]------------
WARNING: CPU: 1 PID: 1602 at arch/x86/mm/pageattr-test.c:226[<
none      >] pageattr_test+0xa6f/0xd10 arch/x86/mm/pageattr-test.c:226
NOT PASSED. Please report.
Modules linked in:
CPU: 1 PID: 1602 Comm: pageattr-test Not tainted 4.7.0-rc2+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 ffffffff880b59e0 ffff88003a41fa70 ffffffff82cc5e2f ffffffff81495ed8
 fffffbfff1016b3c ffff88003a41fae8 0000000000000000 ffffffff86c7a060
 ffffffff8129ac8f 0000000000000009 ffff88003a41fab8 ffffffff8136d23f
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff82cc5e2f>] dump_stack+0x12e/0x18f lib/dump_stack.c:51
 [<ffffffff8136d23f>] __warn+0x19f/0x1e0 kernel/panic.c:516
 [<ffffffff8136d32c>] warn_slowpath_fmt+0xac/0xd0 kernel/panic.c:531
 [<ffffffff8129ac8f>] pageattr_test+0xa6f/0xd10 arch/x86/mm/pageattr-test.c:226
 [<ffffffff8129af4b>] do_pageattr_test+0x1b/0x60 arch/x86/mm/pageattr-test.c:240
 [<ffffffff813d58df>] kthread+0x23f/0x2d0 drivers/block/aoe/aoecmd.c:1303
 [<ffffffff86a8da0f>] ret_from_fork+0x1f/0x40 arch/x86/entry/entry_64.S:389
---[ end trace 1e5de26a2555fc00 ]---