scsi: pm8001: Fix use-after-free for aborted SSP/STP sas_task

scsi: pm8001: Fix use-after-free for aborted SSP/STP sas_task

[ Upstream commit df7abcaa1246e2537ab4016077b5443bb3c09378 ]

Currently a use-after-free may occur if a sas_task is aborted by the upper
layer before we handle the I/O completion in mpi_ssp_completion() or
mpi_sata_completion().

In this case, the following are the two steps in handling those I/O
completions:

 - Call complete() to inform the upper layer handler of completion of
   the I/O.

 - Release driver resources associated with the sas_task in
   pm8001_ccb_task_free() call.

When complete() is called, the upper layer may free the sas_task. As such,
we should not touch the associated sas_task afterwards, but we do so in the
pm8001_ccb_task_free() call.

Fix by swapping the complete() and pm8001_ccb_task_free() calls ordering.

Link: https://lore.kernel.org/r/1643289172-165636-4-git-send-email-john.garry@huawei.com
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>