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
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.
> [<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
>
On Mon, Apr 11, 2016 at 10:52 AM, Andrey Ryabinin
<[email protected]> 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
On 04/11/2016 12:03 PM, Dmitry Vyukov wrote:
> On Mon, Apr 11, 2016 at 10:52 AM, Andrey Ryabinin
> <[email protected]> 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.
No, it's a bug in your script. To find out source location, it uses 'function_name + offset' instead of absolute address.
We have 2 kthread() functions in kernel and this confuses you script.
E.g. my vmlinux :
$ addr2line -i -e vmlinux ffffffff811b5290
/home/andrew/linux/kernel/kthread.c:178
$ addr2line -i -e kasan_conf/vmlinux ffffffff825c7240
/home/andrew/linux/drivers/block/aoe/aoecmd.c:1289
$ echo '[<ffffffff811b5290>] kthread+0x00/0x00' | python kasan_symbolize.py vmlinux
[<ffffffff811b5290>] kthread+0x00/0x00 drivers/block/aoe/aoecmd.c:462
$ echo '[<ffffffff825c7240>] kthread+0x00/0x00' | python kasan_symbolize.py vmlinux
[<ffffffff825c7240>] kthread+0x00/0x00 drivers/block/aoe/aoecmd.c:462
> 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
On Mon, Apr 11, 2016 at 11:32 AM, Andrey Ryabinin
<[email protected]> wrote:
>
>
> On 04/11/2016 12:03 PM, Dmitry Vyukov wrote:
>> On Mon, Apr 11, 2016 at 10:52 AM, Andrey Ryabinin
>> <[email protected]> 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.
>
> No, it's a bug in your script. To find out source location, it uses 'function_name + offset' instead of absolute address.
> We have 2 kthread() functions in kernel and this confuses you script.
>
>
> E.g. my vmlinux :
> $ addr2line -i -e vmlinux ffffffff811b5290
> /home/andrew/linux/kernel/kthread.c:178
> $ addr2line -i -e kasan_conf/vmlinux ffffffff825c7240
> /home/andrew/linux/drivers/block/aoe/aoecmd.c:1289
>
>
> $ echo '[<ffffffff811b5290>] kthread+0x00/0x00' | python kasan_symbolize.py vmlinux
> [<ffffffff811b5290>] kthread+0x00/0x00 drivers/block/aoe/aoecmd.c:462
> $ echo '[<ffffffff825c7240>] kthread+0x00/0x00' | python kasan_symbolize.py vmlinux
> [<ffffffff825c7240>] kthread+0x00/0x00 drivers/block/aoe/aoecmd.c:462
Agree. Filed https://github.com/google/sanitizers/issues/668
Thanks!
>> 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