[PATCH] scsi: qla4xxx: Fix a potential race condition.

[wu000273]

From: Qiushi Wu <wu000273@xxxxxxx>

In the function qla4xxx_eh_abort, we should use lock protect both
kref_get() and kref_put(), because we must serialize access where a
kref_put() cannot occur during the kref_get(). Otherwise, the object
"srb" may not remain valid during the kref_get(), and a race condition
can happen.

Signed-off-by: Qiushi Wu <wu000273@xxxxxxx>
---
 drivers/scsi/qla4xxx/ql4_os.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c
index 5504ab11decc..a1400cadb91a 100644
--- a/drivers/scsi/qla4xxx/ql4_os.c
+++ b/drivers/scsi/qla4xxx/ql4_os.c
@@ -9222,8 +9222,10 @@ static int qla4xxx_eh_abort(struct scsi_cmnd *cmd)
 		    ha->host_no, id, lun));
 		wait = 1;
 	}
-
+
+	spin_lock_irqsave(&ha->hardware_lock, flags);
 	kref_put(&srb->srb_ref, qla4xxx_srb_compl);
+	spin_unlock_irqrestore(&ha->hardware_lock, flags);
 
 	/* Wait for command to complete */
 	if (wait) {
-- 
2.17.1