System crash in mempool_free() when handling I/O coming out of dm_mod

Issue

• System crash in mempool_free() when handling I/O coming out of dm_mod:

sd 3:0:5:1: Warning! Received an indication that the LUN assignments on this target have changed. The Linux SCSI layer does not automatical
sd 5:0:2:1: Warning! Received an indication that the LUN assignments on this target have changed. The Linux SCSI layer does not automatical
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
PGD 0 P4D 0 
Oops: 0002 [#1] SMP PTI
CPU: 4 PID: 1023405 Comm: kworker/4:82 Kdump: loaded Tainted: G           OE    --------- -  - 4.18.0-193.70.1.el8_2.x86_64 #1
Hardware name: HPE ProLiant DL380 Gen10/ProLiant DL380 Gen10, BIOS U30 09/03/2021
Workqueue: lpfc_wq lpfc_sli4_hba_process_cq [lpfc]
RIP: 0010:mempool_free+0x4e/0x80
....
Call Trace:
dec_pending+0xbd/0x210 [dm_mod]
clone_endio+0x88/0x180 [dm_mod]
blk_update_request+0xc0/0x250
blk_update_request+0xc0/0x250
scsi_end_request+0x2c/0x190
scsi_io_completion+0x8c/0x660
blk_mq_complete_request+0x6c/0x100
scsi_mq_done+0x27/0x80
lpfc_scsi_cmd_iocb_cmpl+0x25b/0x970 [lpfc]
? __switch_to_asm+0x35/0x70
? __switch_to_asm+0x41/0x70
? lpfc_sli_iocbq_lookup_by_tag+0x109/0x140 [lpfc]
lpfc_sli4_fp_handle_fcp_wcqe.isra.23+0xd9/0x2f0 [lpfc]
? __switch_to_asm+0x35/0x70
? __switch_to_asm+0x41/0x70
? __switch_to_asm+0x35/0x70
? __switch_to_asm+0x41/0x70
? __switch_to_asm+0x35/0x70
? __switch_to_asm+0x41/0x70
? update_load_avg+0x7c/0x5c0
? update_curr+0xe1/0x1c0
? enqueue_entity+0x108/0x670
? lpfc_bg_scsi_prep_dma_buf_s3+0xb50/0xb50 [lpfc]
? __switch_to_asm+0x41/0x70
? lpfc_sli4_fp_handle_cqe+0x19f/0x490 [lpfc]
? __switch_to_asm+0x41/0x70
lpfc_sli4_fp_handle_cqe+0x19f/0x490 [lpfc]
? __switch_to_asm+0x41/0x70
? __switch_to_asm+0x35/0x70
? __switch_to_asm+0x41/0x70
? __switch_to_asm+0x35/0x70
__lpfc_sli4_process_cq+0xfb/0x230 [lpfc]
? lpfc_sli4_fp_handle_fcp_wcqe.isra.23+0x2f0/0x2f0 [lpfc]
? __switch_to+0x7a/0x3f0
__lpfc_sli4_hba_process_cq+0x39/0x110 [lpfc]
process_one_work+0x1a7/0x3b0
worker_thread+0x30/0x390
? create_worker+0x1a0/0x1a0
kthread+0x112/0x130
? kthread_flush_work_fn+0x10/0x10
ret_from_fork+0x35/0x40