KMSAN: uninit-value in wq_barrier

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KMSAN: uninit-value in wq_barrier_func kernel				3	989d	998d	0/26	auto-closed as invalid on 2021/11/07 19:42

=====================================================
BUG: KMSAN: uninit-value in complete+0x120/0x150 kernel/sched/completion.c:34
 complete+0x120/0x150 kernel/sched/completion.c:34
 wq_barrier_func+0x3b/0x50 kernel/workqueue.c:2652
 process_one_work+0xdc7/0x1760 kernel/workqueue.c:2297
 process_scheduled_works kernel/workqueue.c:2360 [inline]
 worker_thread+0x18ea/0x22b0 kernel/workqueue.c:2449
 kthread+0x66b/0x780 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30

Local variable timer created at:
 schedule_timeout+0x57/0x560 kernel/time/timer.c:1844
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common+0x2e5/0x600 kernel/sched/completion.c:117
=====================================================
Kernel panic - not syncing: kmsan.panic set ...
CPU: 0 PID: 7509 Comm: kworker/0:2 Tainted: G    B             5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: mm_percpu_wq wq_barrier_func
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1ff/0x28e lib/dump_stack.c:106
 dump_stack+0x25/0x28 lib/dump_stack.c:113
 panic+0x44f/0xdeb kernel/panic.c:232
 kmsan_report+0x2e9/0x2f0 mm/kmsan/report.c:205
 __msan_warning+0xb4/0x100 mm/kmsan/instrumentation.c:222
 complete+0x120/0x150 kernel/sched/completion.c:34
 wq_barrier_func+0x3b/0x50 kernel/workqueue.c:2652
 process_one_work+0xdc7/0x1760 kernel/workqueue.c:2297
 process_scheduled_works kernel/workqueue.c:2360 [inline]
 worker_thread+0x18ea/0x22b0 kernel/workqueue.c:2449
 kthread+0x66b/0x780 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30
Kernel Offset: disabled
Rebooting in 86400 seconds..