[PATCH 5.10 358/717] scsi: iscsi: Fix inappropriate use of put_device()

[Greg Kroah-Hartman]

From: Qinglang Miao <miaoqinglang@xxxxxxxxxx>

[ Upstream commit 6dc1c7ab6f047f45b62986ffebc5324e86ed5f5a ]

kfree(conn) is called inside put_device(&conn->dev) which could lead to
use-after-free. In addition, device_unregister() should be used here rather
than put_deviceO().

Link: https://lore.kernel.org/r/20201120074852.31658-1-miaoqinglang@xxxxxxxxxx
Fixes: f3c893e3dbb5 ("scsi: iscsi: Fail session and connection on transport registration failure")
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Reviewed-by: Mike Christie <michael.christie@xxxxxxxxxx>
Signed-off-by: Qinglang Miao <miaoqinglang@xxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/scsi/scsi_transport_iscsi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 2eb3e4f9375a5..2e68c0a876986 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -2313,7 +2313,9 @@ iscsi_create_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid)
 	return conn;
 
 release_conn_ref:
-	put_device(&conn->dev);
+	device_unregister(&conn->dev);
+	put_device(&session->dev);
+	return NULL;
 release_parent_ref:
 	put_device(&session->dev);
 free_conn:
-- 
2.27.0