BUG: workqueue lockup (4)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    c1d84a1b42ef Merge git://git.kernel.org/pub/scm/linux/kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14c5f491400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c0af03fe452b65fb
dashboard link: https://syzkaller.appspot.com/bug?extid=08116743f8ad6f9a6de7
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14514a6e400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1025ebb9400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+08116743f8ad6f9a6de7@xxxxxxxxxxxxxxxxxxxxxxxxx

BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 204s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x0
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=4/256
    in-flight: 14:rtc_timer_do_work
    pending: vmstat_shepherd, cache_reap, check_corruption
workqueue events_power_efficient: flags=0x80
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
    pending: do_cache_clean
workqueue mm_percpu_wq: flags=0x8
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256
    pending: vmstat_update
workqueue kacpi_notify: flags=0x0
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1
    pending: acpi_os_execute_deferred
pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=204s workers=2 idle: 2683


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