The system was crashed at 'kthread_stop+0xf' called from 'defer_io_stop'

Issue

• System was crashed with the below log in vmcore.

...
[33390.977305] BUG: unable to handle kernel NULL pointer dereference at 000000000000001c
[33390.977381] PGD 12f9bb067 P4D 19c9b7067 PUD 1335da067 PMD 0 
[33390.977433] Oops: 0002 [#1] SMP NOPTI
[33390.977466] CPU: 13 PID: 671608 Comm: snapshot operat Kdump: loaded Tainted: P           OE    --------- -  - 4.18.0-477.10.1.el8_8.x86_64 #1
[33390.977557] Hardware name: HPE ProLiant DL380 Gen10 Plus/ProLiant DL380 Gen10 Plus, BIOS U46 06/01/2022
[33390.977621] RIP: 0010:kthread_stop+0xf/0x110
[33390.977664] Code: e6 0a 48 29 c6 48 81 c6 e0 35 21 98 e8 da f7 ff ff eb b6 0f 0b eb a4 0f 1f 40 00 0f 1f 44 00 00 55 53 48 89 fb 0f 1f 44 00 00 <f0> ff 43 20 0f 88 33 1a 8d 00 f6 43 26 20 0f 84 dd 00 00 00 48 8b
[33390.977791] RSP: 0018:ff27c9178149bce0 EFLAGS: 00010286
[33390.977833] RAX: 0000000000000000 RBX: fffffffffffffffc RCX: 0000000000000000
[33390.977852] RDX: 0000000000000001 RSI: 0000000000000246 RDI: fffffffffffffffc
[33390.977864] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffc0d457b8
[33390.977876] R10: ff27c9178149bcd8 R11: ff27c9178149bc03 R12: 0000000000000008
[33390.977888] R13: 0000000000000001 R14: ff27c9178149bd60 R15: ff1143a75799fbc0
[33390.977900] FS:  00007f8a93fff700(0000) GS:ff1143e53d340000(0000) knlGS:0000000000000000
[33390.977914] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[33390.977925] CR2: 000000000000001c CR3: 000000012f630005 CR4: 0000000000771ee0
[33390.977937] PKRU: 55555554
[33390.977943] Call Trace:
[33390.977953]  defer_io_stop+0x4e/0x90 [veeamsnap]
[33390.977971]  _defer_io_destroy.part.5+0x4a/0xa0 [veeamsnap]
[33390.977984]  defer_io_create+0x156/0x200 [veeamsnap]
[33390.977997]  _tracker_capture_snapshot+0x37/0x140 [veeamsnap]
[33390.978012]  tracker_capture_snapshot+0x46/0x290 [veeamsnap]
[33390.978026]  snapshot_Create+0x17d/0x2a0 [veeamsnap]
[33390.978040]  ioctl_snapshot_create+0x13a/0x1e0 [veeamsnap]
[33390.978054]  ctrl_unlocked_ioctl+0x4e/0x60 [veeamsnap]
[33390.978068]  do_vfs_ioctl+0xa4/0x690
[33390.978078]  ksys_ioctl+0x64/0xa0
[33390.978086]  __x64_sys_ioctl+0x16/0x20
[33390.978093]  do_syscall_64+0x5b/0x1b0
[33390.978104]  entry_SYSCALL_64_after_hwframe+0x61/0xc6
[33390.978116] RIP: 0033:0x7f8b66f6d7cb
...