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

From: wu000273
Date: Tue Apr 21 2020 - 17:09:06 EST


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