Re: [External] Re: [PATCH v2] perf/core: Fix pending work re-queued in __perf_event_overflow

[Liangyan]

On 2025/11/11 21:30, Sebastian Andrzej Siewior wrote:
> On 2025-11-10 00:41:22 [+0800], Liangyan wrote:
>> We got warning below during perf test.
> …
>>
>> A race condition occurs between task context and IRQ context when
>> handling sigtrap tracepoint event overflows:
>>
>> 1. In task context, an event is overflowed and its pending work is
>>    queued to task->task_works
>> 2. Before pending_work is set, the same event overflows in IRQ context
>> 3. Both contexts queue the same perf pending work to task->task_works
>>
>> This double queuing causes:
>> - task_work_run() enters infinite loop calling perf_pending_task()
>> - Potential warnings and use-after-free when event is freed in
>> perf_pending_task()
>>
>> Fix the race by disabling interrupts during queuing of perf pending work.
> 
> Makes sense. Lets it does not overflow in NMI, too.
> Either way I suggest to trim the commit message and remove the
> backtrace as it probably does not add any value.
> 
> Sebastian

Got it, I will remove the backtrace in the following version.