Re: perf: use-after-free in perf_release

[Peter Zijlstra]

On Tue, Mar 07, 2017 at 02:16:49PM +0100, Peter Zijlstra wrote:
> So I _think_ find_task_by_vpid() can return an already dead task; and
> we'll happily increase task->usage.

Hurm, so find_get_context() already does the PF_EXITING test. And then
the put_ctx would've been from find_get_context(), not fput().

So still puzzled.