[PATCH] scsi: iscsi_tcp: Check the sock is correct before iscsi_set_param

[PATCH] scsi: iscsi_tcp: Check the sock is correct before iscsi_set_param

[Zhong Jinghua]

From: Zhong Jinghua <zhongjinghua@huawei.com>

The correctness of sock should be checked before assignment to avoid
assigning wrong values.

Commit
"scsi: iscsi: iscsi_tcp: Fix null-ptr-deref while calling getpeername()"
introduced this change. This change may lead to inconsistent values of
tcp_sw_conn->sendpage and conn->datadgst_en.

Fix it by moving the position of the assignment.

Fixes: 57569c37f0ad ("scsi: iscsi: iscsi_tcp: Fix null-ptr-deref while calling getpeername()")
Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>
---
 drivers/scsi/iscsi_tcp.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 882e8b81b490..b32f3ca3e7d0 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -726,13 +726,12 @@ static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
 		iscsi_set_param(cls_conn, param, buf, buflen);
 		break;
 	case ISCSI_PARAM_DATADGST_EN:
-		iscsi_set_param(cls_conn, param, buf, buflen);
-
 		mutex_lock(&tcp_sw_conn->sock_lock);
 		if (!tcp_sw_conn->sock) {
 			mutex_unlock(&tcp_sw_conn->sock_lock);
 			return -ENOTCONN;
 		}
+		iscsi_set_param(cls_conn, param, buf, buflen);
 		tcp_sw_conn->sendpage = conn->datadgst_en ?
 			sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
 		mutex_unlock(&tcp_sw_conn->sock_lock);
-- 
2.31.1

Re: [PATCH] scsi: iscsi_tcp: Check the sock is correct before iscsi_set_param

[Mike Christie]

On 3/29/23 2:17 AM, Zhong Jinghua wrote:
> From: Zhong Jinghua <zhongjinghua@huawei.com>
> 
> The correctness of sock should be checked before assignment to avoid
> assigning wrong values.
> 
> Commit
> "scsi: iscsi: iscsi_tcp: Fix null-ptr-deref while calling getpeername()"
> introduced this change. This change may lead to inconsistent values of
> tcp_sw_conn->sendpage and conn->datadgst_en.
> 
> Fix it by moving the position of the assignment.
> 
> Fixes: 57569c37f0ad ("scsi: iscsi: iscsi_tcp: Fix null-ptr-deref while calling getpeername()")
> Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>

Thanks.

Reviewed-by: Mike Christie <michael.christie@oracle.com>