The kernel crashes due to a blocked task that is calling flush_work() and waiting for the completion.

Issue

• The kernel crashes due to a blocked task that is calling flush_work() and waiting for the completion:

[ 4035.477796] Kernel panic - not syncing:
[ 4035.477797] hung_task: blocked tasks
[ 4035.477798] CPU: 33 PID: 642 Comm: khungtaskd Kdump: loaded Tainted: G           OE    --------- -  - 4.18.0-372.49.1.rt7.206.el8_6.x86_64 #1
[ 4035.477800] Hardware name: Dell Inc. PowerEdge XR11/0P2RNT, BIOS 1.9.2 11/17/2022
[ 4035.477801] Call Trace:
[ 4035.477803]  dump_stack+0x41/0x60
[ 4035.477806]  panic+0xb9/0x2cd
[ 4035.477810]  watchdog+0x259/0x370
[ 4035.477813]  ? hungtask_pm_notify+0x50/0x50
[ 4035.477815]  kthread+0x151/0x170
[ 4035.477817]  ? set_kthread_struct+0x50/0x50
[ 4035.477820]  ret_from_fork+0x1f/0x40

crash> ps -m ff206e3bc4290000
[0 00:19:02.341] [UN]  PID: 190876   TASK: ff206e3bc4290000  CPU: 23   COMMAND: "sysctl"

PID: 190876   TASK: ff206e3bc4290000  CPU: 23   COMMAND: "sysctl"
 #0 [ff242d994ca4bc18] __schedule at ffffffff8d9d32db
 #1 [ff242d994ca4bc70] schedule at ffffffff8d9d387d
 #2 [ff242d994ca4bc88] schedule_timeout at ffffffff8d9dbc97
 #3 [ff242d994ca4bd20] wait_for_completion at ffffffff8d9d4d24
 #4 [ff242d994ca4bd60] flush_work at ffffffff8d10b310
 #5 [ff242d994ca4be18] schedule_on_each_cpu at ffffffff8d10d9e7
 #6 [ff242d994ca4be40] vmstat_refresh at ffffffff8d2bd662
 #7 [ff242d994ca4be70] proc_sys_call_handler at ffffffff8d3dd2b4
 #8 [ff242d994ca4bec8] vfs_read at ffffffff8d3491c1
 #9 [ff242d994ca4bf00] ksys_read at ffffffff8d349632
#10 [ff242d994ca4bf38] do_syscall_64 at ffffffff8d002d47
#11 [ff242d994ca4bf50] entry_SYSCALL_64_after_hwframe at ffffffff8da000a9
    RIP: 00007fdfa195bb40  RSP: 00007ffc50535b98  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 0000000000cfeb90  RCX: 00007fdfa195bb40
    RDX: 0000000000000400  RSI: 00007fdfa24a9000  RDI: 0000000000000005
    RBP: 00007fdfa1c30380   R8: ffffffffffffffff   R9: 0000000000000000
    R10: 0000000000000022  R11: 0000000000000246  R12: 00007fdfa1c2f838
    R13: 00007fdfa1c2f838  R14: 0000000000000d70  R15: 00007fdfa1c305a8
    ORIG_RAX: 0000000000000000  CS: 0033  SS: 002b