Comment # 8 on bug 1190093 from Jiri Slaby

> BUG: kernel NULL pointer dereference, address: 0000000000000428
> #PF: supervisor read access in kernel mode
> #PF: error_code(0x0000) - not-present page
> PGD 0 P4D 0
> Oops: 0000 [#1] SMP PTI
> CPU: 3 PID: 9698 Comm: kworker/u8:8 Kdump: loaded Not tainted 5.14.0-1.gdc06e24-default #1 openSUSE Tumbleweed (unreleased) 0db17d91eb25d13cad5ace6687cd8bc952dc29d3
> Hardware name: Dell Inc. Latitude 7280/0KK5D1, BIOS 1.16.1 10/03/2019
> Workqueue: events_unbound async_run_entry_fn
> RIP: 0010:hrtimer_active+0x5/0x40
> Code: d1 48 8d 3c 16 4c 01 d2 49 89 78 18 48 89 fe 49 89 d2 49 89 50 20 49 39 fb 7d 04 c3 0f 0b c3 48 83 c0 01 eb 98 0f 1f 44 00 00 <48> 8b 57 30 8b 42 10 a8 01 74 09 f3 90 8b 42 10 a8 01 75 f7 80 7f
> RSP: 0000:ffffb7cc837ebc78 EFLAGS: 00010202
> RAX: 0000000000000000 RBX: 00000000000003f8 RCX: 000000000158a204
> RDX: ffff8e63be521280 RSI: 0000000000000000 RDI: 00000000000003f8
> RBP: ffff8e6046e6ea00 R08: 000000000000000f R09: 0000000000000000
> R10: ffff8e60d8dfdf01 R11: 0000000000000000 R12: ffff8e604ab9b000
> R13: ffff8e604ab9b358 R14: 0000000000000002 R15: 0000000000000000
> FS:  0000000000000000(0000) GS:ffff8e63be580000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000428 CR3: 000000047cc10005 CR4: 00000000003706e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  hrtimer_cancel+0x11/0x40
>  watchdog_cdev_unregister+0x92/0xe0
>  watchdog_unregister_device+0x4e/0xe0
>  mei_wdt_remove+0x59/0xd0 [mei_wdt 544586a9e1951b9111a05508f4aa01c244e4d749]
>  mei_cl_device_remove+0x22/0x90 [mei 74f17d37dc3b283a8402706fa76f8a3ddbb59c6c]
>  __device_release_driver+0x17a/0x230
>  device_release_driver+0x24/0x30
>  mei_cl_bus_remove_devices+0x5b/0x70 [mei 74f17d37dc3b283a8402706fa76f8a3ddbb59c6c]
>  mei_stop+0x3c/0xf0 [mei 74f17d37dc3b283a8402706fa76f8a3ddbb59c6c]
>  mei_me_pci_suspend+0x26/0x80 [mei_me 844d2501e9b5802ee255d5a7462d42dd8e37258a]
>  pci_pm_suspend+0x74/0x160
>  dpm_run_callback+0x49/0x120
>  __device_suspend+0x18e/0x540
>  async_suspend+0x1b/0x90
>  async_run_entry_fn+0x2e/0x110
>  process_one_work+0x1df/0x380
>  worker_thread+0x50/0x410
>  kthread+0x127/0x150
>  ret_from_fork+0x22/0x30

This fix is in -next already:
commit c7b178dae139f8857edc50888cfbf251cd974a38
Author: Curtis Klein <curtis.klein@hpe.com>
Date:   Tue Jun 22 23:26:23 2021 -0700

    watchdog: Fix NULL pointer dereference when releasing cdev