Re: perf: use-after-free in perf_release

[Oleg Nesterov]

On 03/06, Peter Zijlstra wrote:
>
> and this is a failed fork().
>
>
> However, inherited events don't have a filedesc to fput(), and
> similarly, a task that fails for has never been visible to attach a perf
> event to because it never hits the pid-hash.

Yes, it is not visible to find_task_by_vpid() until copy_process() does
attach_pid(PIDTYPE_PID), and copy_process() can't fail after that.

Oleg.