From 55b2e929a3831b269c69e5f437860d71b3f99efa Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 10 Jun 2019 09:08:27 -0700 Subject: [PATCH] cgroup: Fix css_task_iter_advance_css_set() cset skip condition commit c596687a008b579c503afb7a64fcacc7270fae9e upstream. While adding handling for dying task group leaders c03cd7738a83 ("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 Fixes: c03cd7738a83 ("cgroup: Include dying leaders with live threads in PROCS iterations") Reported-by: syzbot+d4bba5ccd4f9a2a68681@syzkaller.appspotmail.com Signed-off-by: Greg Kroah-Hartman --- kernel/cgroup/cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 2fb283f689a4..2c57030f54aa 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -4048,7 +4048,7 @@ 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;