Re: uprobes/perf: KASAN: use-after-free in uprobe_perf_close

[Peter Zijlstra]

On Mon, Apr 09, 2018 at 12:40:10PM +0200, Oleg Nesterov wrote:
> But I still think that we should (try to) remove put_task_struct() from put_ctx().
> 
> Quite possibly I missed something, but I think it only adds some confusion. Once
> again, even if ctx can't go away you can't use ctx->task without TASK_TOMBSTONE
> check, exactly because this task can exit. So why perf_event_context should add
> another reference?

Ah, I see what you mean. Yes that might be possible.