[Devel] [PATCH -mm] utrace: fix double free re __rcu_process_callbacks()

[Alexey Dobriyan]

On Tue, Apr 24, 2007 at 01:10:23PM +0400, Alexey Dobriyan wrote:
> ¹ But I see whole can of other bugs! I think they were already lurking
>   but weren't easily reproducable without hitting double-free first.
>   FWIW, it's
>   	BUG_ON(!list_empty(&tsk->ptracees));

mmm, pretty easily reproduced with:

	while true; do
		killall -9 expl_ptratt 2>/dev/null;
		killall -9 exe 2>/dev/null;
		sleep 2;
	done
vs
	while true; do ./expl_ptratt; done