In the Linux kernel, the following vulnerability has been resolved:

scsi: lpfc: Fix SCSI I/O completion and abort handler deadlock

During stress I/O tests with 500+ vports, hard LOCKUP call traces are
observed.

CPU A:
 native_queued_spin_lock_slowpath+0x192
 _raw_spin_lock_irqsave+0x32
 lpfc_handle_fcp_err+0x4c6
 lpfc_fcp_io_cmd_wqe_cmpl+0x964
 lpfc_sli4_fp_handle_cqe+0x266
 __lpfc_sli4_process_cq+0x105
 __lpfc_sli4_hba_process_cq+0x3c
 lpfc_cq_poll_hdler+0x16
 irq_poll_softirq+0x76
 __softirqentry_text_start+0xe4
 irq_exit+0xf7
 do_IRQ+0x7f

CPU B:
 native_queued_spin_lock_slowpath+0x5b
 _raw_spin_lock+0x1c
 lpfc_abort_handler+0x13e
 scmd_eh_abort_handler+0x85
 process_one_work+0x1a7
 worker_thread+0x30
 kthread+0x112
 ret_from_fork+0x1f

Diagram of lockup:

CPUA                            CPUB
----                            ----
lpfc_cmd->buf_lock
                            phba->hbalock
                            lpfc_cmd->buf_lock
phba->hbalock

Fix by reordering the taking of the lpfc_cmd->buf_lock and phba->hbalock in
lpfc_abort_handler routine so that it tries to take the lpfc_cmd->buf_lock
first before phba->hbalock.

https://git.kernel.org/stable/c/03cbbd7c2f5ee288f648f4aeedc765a181188553

https://git.kernel.org/stable/c/0c4eed901285b9cae36a622f32bea3e92490da6c

https://git.kernel.org/stable/c/21c0d469349957b5dc811c41200a2a998996ca8d

https://git.kernel.org/stable/c/7625e81de2164a082810e1f27547d388406da610