[PATCH 2/2] iscsi_tcp: Check if tcp_conn is valid in

[Wenchao Hao]

iscsi_create_conn() would add newly alloced iscsi_cls_conn to connlist,
it means when userspace sends ISCSI_UEVENT_SET_PARAM, iscsi_conn_lookup()
would found this iscsi_cls_conn and call the set_param callback which is
iscsi_sw_tcp_conn_set_param(). While the iscsi_conn's dd_data might not
been initialized.

Signed-off-by: Wenchao Hao <haowenchao@xxxxxxxxxx>
Signed-off-by: Wu Bo <wubo40@xxxxxxxxxx>
---
 drivers/scsi/iscsi_tcp.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 14db224486be..a42449df6156 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -716,13 +716,17 @@ static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
 {
 	struct iscsi_conn *conn = cls_conn->dd_data;
 	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
-	struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
+	struct iscsi_sw_tcp_conn *tcp_sw_conn;
 
 	switch(param) {
 	case ISCSI_PARAM_HDRDGST_EN:
 		iscsi_set_param(cls_conn, param, buf, buflen);
 		break;
 	case ISCSI_PARAM_DATADGST_EN:
+		if (!tcp_conn || !tcp_conn->dd_data)
+			return -ENOTCONN;
+
+		tcp_sw_conn = tcp_conn->dd_data;
 		iscsi_set_param(cls_conn, param, buf, buflen);
 		tcp_sw_conn->sendpage = conn->datadgst_en ?
 			sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
-- 
2.32.0