scsi: lpfc: Fix list_add() corruption in lpfc_drain_txq()

stable inclusion
from stable-v4.19.218
commit b291d147d0268e93ad866f8bc820ea14497abc9b
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9FNFI
CVE: CVE-2021-47203

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b291d147d0268e93ad866f8bc820ea14497abc9b

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[ Upstream commit 99154581 ]

When parsing the txq list in lpfc_drain_txq(), the driver attempts to pass
the requests to the adapter. If such an attempt fails, a local "fail_msg"
string is set and a log message output.  The job is then added to a
completions list for cancellation.

Processing of any further jobs from the txq list continues, but since
"fail_msg" remains set, jobs are added to the completions list regardless
of whether a wqe was passed to the adapter.  If successfully added to
txcmplq, jobs are added to both lists resulting in list corruption.

Fix by clearing the fail_msg string after adding a job to the completions
list. This stops the subsequent jobs from being added to the completions
list unless they had an appropriate failure.

Link: https://lore.kernel.org/r/20210910233159.115896-2-jsmart2021@gmail.com


Co-developed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zucheng <zhengzucheng@huawei.com>