Re: WARNING in strp_data_ready

From: Dmitry Vyukov
Date: Thu Dec 28 2017 - 11:33:48 EST


On Thu, Dec 28, 2017 at 5:14 PM, Tom Herbert <tom@xxxxxxxxxxxxxxx> wrote:
> On Thu, Dec 28, 2017 at 12:59 AM, Ozgur <ozgur@xxxxxxxxxx> wrote:
>>
>>
>> 28.12.2017, 04:19, "Tom Herbert" <tom@xxxxxxxxxxxxxxx>:
>>> On Wed, Dec 27, 2017 at 12:20 PM, Ozgur <ozgur@xxxxxxxxxx> wrote:
>>>> 27.12.2017, 23:14, "Dmitry Vyukov" <dvyukov@xxxxxxxxxx>:
>>>>> On Wed, Dec 27, 2017 at 9:08 PM, Ozgur <ozgur@xxxxxxxxxx> wrote:
>>>>>> 27.12.2017, 22:21, "Dmitry Vyukov" <dvyukov@xxxxxxxxxx>:
>>>>>>> On Wed, Dec 27, 2017 at 8:09 PM, Tom Herbert <tom@xxxxxxxxxxxxxxx> wrote:
>>>>>>>> Did you try the patch I posted?
>>>>>>>
>>>>>>> Hi Tom,
>>>>>>
>>>>>> Hello Dmitry,
>>>>>>
>>>>>>> No. And I didn't know I need to. Why?
>>>>>>> If you think the patch needs additional testing, you can ask syzbot to
>>>>>>> test it. See https://github.com/google/syzkaller/blob/master/docs/syzbot.md#communication-with-syzbot
>>>>>>> Otherwise proceed with committing it. Or what are we waiting for?
>>>>>>>
>>>>>>> Thanks
>>>>>>
>>>>>> I think we need to fixed patch for crash, in fact check to patch code and test solve the bug.
>>>>>> How do test it because there is no patch in the following bug?
>>>>>
>>>>> Hi Ozgur,
>>>>>
>>>>> I am not sure I completely understand what you mean. But the
>>>>> reproducer for this bug (which one can use for testing) is here:
>>>>> https://groups.google.com/forum/#!topic/syzkaller-bugs/Kxs05ziCpgY
>>>>> Tom also mentions there is some patch for this, but I don't know where
>>>>> it is, it doesn't seem to be referenced from this thread.
>>>>
>>>> Hello Dmitry,
>>>>
>>>> Ah, I'm sorry I don't seen Tom mail and I don't have a patch not tested :)
>>>> I think Tom send patch to only you and are you tested?
>>>>
>>>> kcmsock.c will change and strp_data_ready I think locked.
>>>>
>>>> Tom, please send a patch for me? I can test and inform you.
>>>
>>> Hi Ozgur,
>>>
>>> I reposted the patches as RFC "kcm: Fix lockdep issue". Please test if you can!
>>>
>>> Thanks,
>>> Tom
>>
>> Hello Tom,
>>
>> Which are you use the repos? I pulled but I don't seen this patches.
>>
> They are not in any public repo yet. I posted the patches to netdev
> list so they can be reviewed and tested by third parties. Posting
> patches to the list a normal path to get patches into the kernel
> (http://nickdesaulniers.github.io/blog/2017/05/16/submitting-your-first-patch-to-the-linux-kernel-and-responding-to-feedback/).
>
> These patches were applied to net-next but are simple enough that they
> should apply to other branches. I will repost and target to net per
> Dave's directive once they are verified to fix the issue.

FWIW they are already verified to fix the issue, see few emails up, also here:
https://groups.google.com/d/msg/syzkaller-bugs/Kxs05ziCpgY/fPdZcO_GAwAJ
and don't forget this:
https://groups.google.com/d/msg/syzkaller-bugs/Kxs05ziCpgY/uGjsrA3HAwAJ