Commit c596687a authored Jun 10, 2019 by Tejun Heo

cgroup: Fix css_task_iter_advance_css_set() cset skip condition



While adding handling for dying task group leaders c03cd773
("cgroup: Include dying leaders with live threads in PROCS
iterations") added an inverted cset skip condition to
css_task_iter_advance_css_set().  It should skip cset if it's
completely empty but was incorrectly testing for the inverse condition
for the dying_tasks list.  Fix it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: c03cd773 ("cgroup: Include dying leaders with live threads in PROCS iterations")
Reported-by:  <syzbot+d4bba5ccd4f9a2a68681@syzkaller.appspotmail.com>

parent cee0c33c

kernel/cgroup/cgroup.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -4401,7 +4401,7 @@ static void css_task_iter_advance_css_set(struct css_task_iter *it)
		it->task_pos = NULL;
		return;
		}
		} while (!css_set_populated(cset) && !list_empty(&cset->dying_tasks));
		} while (!css_set_populated(cset) && list_empty(&cset->dying_tasks));

		if (!list_empty(&cset->tasks))
		it->task_pos = cset->tasks.next;