[PATCH] scsi: qla2xxx: avoid crash in qlt_handle_abts_completion() if mcmd == NULL

[Thomas Abraham]

qlt_ctio_to_cmd() will return a NULL mcmd if h == QLA_TGT_SKIP_HANDLE. If
the error subcodes don't match the exact codes checked a crash will occur
when calling free_mcmd on the null mcmd

Signed-off-by: Thomas Abraham <tabraham@xxxxxxxx>
---
 drivers/scsi/qla2xxx/qla_target.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index a06e56224a55..611ab224662f 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -5732,7 +5732,8 @@ static void qlt_handle_abts_completion(struct scsi_qla_host *vha,
 			    vha->vp_idx, entry->compl_status,
 			    entry->error_subcode1,
 			    entry->error_subcode2);
-			ha->tgt.tgt_ops->free_mcmd(mcmd);
+			if (mcmd)
+				ha->tgt.tgt_ops->free_mcmd(mcmd);
 		}
 	} else if (mcmd) {
 		ha->tgt.tgt_ops->free_mcmd(mcmd);
-- 
2.16.4