Re: WARNING in proc_register

[Dmitry Vyukov]

On Tue, Feb 6, 2018 at 2:53 PM, Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
> On Mon, Feb 5, 2018 at 8:41 PM, Alexey Dobriyan <adobriyan@xxxxxxxxx> wrote:
>> On Mon, Feb 05, 2018 at 09:58:01AM -0800, syzbot wrote:
>>> proc_dir_entry 'ipt_CLUSTERIP/172.20.0.170' already registered
>>> WARNING: CPU: 1 PID: 4074 at fs/proc/generic.c:330
>>
>>>   proc_create_data+0xf8/0x180 fs/proc/generic.c:494
>>>   clusterip_config_init net/ipv4/netfilter/ipt_CLUSTERIP.c:250 [inline]
>>
>> Dima, this warning is never about /proc but always about some other code
>> registering duplicate /proc entry.
>>
>> I don't know how easily scriptable is mail sender but you want to look at
>> the second line in the backtrace.
>
> Hi Alexey,
>
> This is now fixed with:
> https://github.com/google/syzkaller/commit/645ce5da79c9654c314f0d12f4c11f2a94ec156b
> In particular tests for this report:
> https://github.com/google/syzkaller/blob/master/pkg/report/testdata/linux/report/181
> https://github.com/google/syzkaller/blob/master/pkg/report/testdata/linux/guilty/30
>
> Thanks for the suggestion.

As the result this now reappeared as "WARNING: proc registration bug
in clusterip_tg_check":
https://groups.google.com/forum/#!topic/syzkaller-bugs/gkFWUsDo0gw

#syz dup: WARNING: proc registration bug in clusterip_tg_check