Commit ce9bc3b2 authored Jun 17, 2020 by Juri Lelli Committed by Borislav Petkov Jun 28, 2020

sched/deadline: Initialize ->dl_boosted



syzbot reported the following warning triggered via SYSC_sched_setattr():

  WARNING: CPU: 0 PID: 6973 at kernel/sched/deadline.c:593 setup_new_dl_entity /kernel/sched/deadline.c:594 [inline]
  WARNING: CPU: 0 PID: 6973 at kernel/sched/deadline.c:593 enqueue_dl_entity /kernel/sched/deadline.c:1370 [inline]
  WARNING: CPU: 0 PID: 6973 at kernel/sched/deadline.c:593 enqueue_task_dl+0x1c17/0x2ba0 /kernel/sched/deadline.c:1441

This happens because the ->dl_boosted flag is currently not initialized by
__dl_clear_params() (unlike the other flags) and setup_new_dl_entity()
rightfully complains about it.

Initialize dl_boosted to 0.

Fixes: 2d3d891d ("sched/deadline: Add SCHED_DEADLINE inheritance logic")
Reported-by:  <syzbot+5ac8bac25f95e8b221e7@syzkaller.appspotmail.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Daniel Wagner <dwagner@suse.de>
Link: https://lkml.kernel.org/r/20200617072919.818409-1-juri.lelli@redhat.com

parent fd844ba9

kernel/sched/deadline.c

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -2692,6 +2692,7 @@ void __dl_clear_params(struct task_struct *p)
	dl_se->dl_bw = 0;		dl_se->dl_bw = 0;
	dl_se->dl_density = 0;		dl_se->dl_density = 0;

			dl_se->dl_boosted = 0;
	dl_se->dl_throttled = 0;		dl_se->dl_throttled = 0;
	dl_se->dl_yielded = 0;		dl_se->dl_yielded = 0;
	dl_se->dl_non_contending = 0;		dl_se->dl_non_contending = 0;

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