[PATCH] signal: Avoid corrupting si_pid and si_uid in do_notify_parent

[Oleg Nesterov]

On 04/21, Christian Brauner wrote:
>
> process B setnses into
> <pidnsC> which is a sibling pid namespace,

please see pidns_install(), it verifies that

	* Only allow entering the current active pid namespace
	* or a child of the current active pid namespace.

Oleg.