scsi: ufs: core: Fix ufshcd_abort_one racing issue

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

scsi: ufs: core: Fix ufshcd_abort_one racing issue

When ufshcd_abort_one is racing with the completion ISR, the completed tag

of the request's mq_hctx pointer will be set to NULL by ISR. Return

success when request is completed by ISR because ufshcd_abort_one does not

need to do anything.

The racing flow is:

Thread A

ufshcd_err_handler step 1

...

ufshcd_abort_one

ufshcd_try_to_abort_task

ufshcd_cmd_inflight(true) step 3

ufshcd_mcq_req_to_hwq

blk_mq_unique_tag

rq->mq_hctx->queue_num step 5

Thread B

ufs_mtk_mcq_intr(cq complete ISR) step 2

scsi_done

...

__blk_mq_free_request

rq->mq_hctx = NULL; step 4

Below is KE back trace.

ufshcd_try_to_abort_task: cmd at tag 41 not pending in the device.

ufshcd_try_to_abort_task: cmd at tag=41 is cleared.

Aborting tag 41 / CDB 0x28 succeeded

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000194

pc : [0xffffffddd7a79bf8] blk_mq_unique_tag+0x8/0x14

lr : [0xffffffddd6155b84] ufshcd_mcq_req_to_hwq+0x1c/0x40 [ufs_mediatek_mod_ise]

do_mem_abort+0x58/0x118

el1_abort+0x3c/0x5c

el1h_64_sync_handler+0x54/0x90

el1h_64_sync+0x68/0x6c

blk_mq_unique_tag+0x8/0x14

ufshcd_err_handler+0xae4/0xfa8 [ufs_mediatek_mod_ise]

process_one_work+0x208/0x4fc

worker_thread+0x228/0x438

kthread+0x104/0x1d4

ret_from_fork+0x10/0x20