Commit d2308225 authored Apr 02, 2014 by Oleg Nesterov Committed by Linus Torvalds Apr 02, 2014

pid_namespace: pidns_get() should check task_active_pid_ns() != NULL

pidns_get()->get_pid_ns() can hit ns == NULL. This task_struct can't
go away, but task_active_pid_ns(task) is NULL if release_task(task)
was already called. Alternatively we could change get_pid_ns(ns) to
check ns != NULL, but it seems that other callers are fine.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman ebiederm@xmission.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 7cbb39d4

kernel/pid_namespace.c

+3 −1

Original line number	Original line	Diff line number	Diff line
	@@ -318,7 +318,9 @@ static void pidns_get(struct task_struct task)
	struct pid_namespace *ns;		struct pid_namespace *ns;

	rcu_read_lock();		rcu_read_lock();
	ns = get_pid_ns(task_active_pid_ns(task));		ns = task_active_pid_ns(task);
			if (ns)
			get_pid_ns(ns);
	rcu_read_unlock();		rcu_read_unlock();

	return ns;		return ns;