[PATCH 00/14] Make the user mode driver code a better citizen

[Tetsuo Handa]

On 2020/07/01 6:57, Alexei Starovoitov wrote:
>>>>> They were all should never happen cases.  Which is why my patches do:
>>>>> if (WARN_ON_ONCE(...))
>>>>
>>>> No. Fuzz testing (which uses panic_on_warn=1) will trivially hit them.
>>>
>>> I don't believe that's true.
>>> Please show fuzzing stack trace to prove your point.
>>>
>>
>> Please find links containing "WARNING" from https://syzkaller.appspot.com/upstream . ;-)
> 
> Is it a joke? Do you understand how syzbot works?
> If so, please explain how it can invoke umd_* interface.
> 

Currently syzkaller can't invoke umd_* interface because this interface is used by only
bpfilter_umh module. But I can imagine that someone starts using this interface in a way
syzkaller can somehow invoke. Thus, how can it be a joke? I don't understand your question.