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From:   Wenchao Hao <haowenchao@huawei.com>
To:     Mike Christie <michael.christie@oracle.com>,
        Lee Duncan <lduncan@suse.com>, Chris Leech <cleech@redhat.com>,
        "James E . J . Bottomley" <jejb@linux.ibm.com>,
        "Martin K . Petersen" <martin.petersen@oracle.com>,
        <open-iscsi@googlegroups.com>, <linux-scsi@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
CC:     Wu Bo <wubo40@huawei.com>, Zhiqiang Liu <liuzhiqiang26@huawei.com>,
        Wenchao Hao <haowenchao@huawei.com>
Subject: [PATCH 2/2] scsi:libiscsi: Add iscsi_cls_conn to sysfs after been initialized
Date:   Mon, 7 Mar 2022 19:56:54 -0500
Message-ID: <20220308005654.2281343-3-haowenchao@huawei.com>
In-Reply-To: <20220308005654.2281343-1-haowenchao@huawei.com>
References: <20220308005654.2281343-1-haowenchao@huawei.com>
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iscsi_create_conn() would expose iscsi_cls_conn to sysfs, while the
initialization of iscsi_conn's dd_data is not ready now. When userspace
try to access an attribute such as connect's address, it might cause
a NULL pointer dereference.

So we should add iscsi_cls_conn to sysfs until it has been initialized.

Signed-off-by: Wenchao Hao <haowenchao@huawei.com>
Signed-off-by: Wu Bo <wubo40@huawei.com>
---
 drivers/scsi/libiscsi.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 059dae8909ee..1cf25f4acb71 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -3040,8 +3040,9 @@ iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
 	struct iscsi_conn *conn;
 	struct iscsi_cls_conn *cls_conn;
 	char *data;
+	int err;
 
-	cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
+	cls_conn = iscsi_alloc_conn(cls_session, sizeof(*conn) + dd_size,
 				     conn_idx);
 	if (!cls_conn)
 		return NULL;
@@ -3078,13 +3079,21 @@ iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
 		goto login_task_data_alloc_fail;
 	conn->login_task->data = conn->data = data;
 
+	err = iscsi_add_conn(cls_conn);
+	if (err)
+		goto login_task_add_dev_fail;
+
 	return cls_conn;
 
+login_task_add_dev_fail:
+	free_pages((unsigned long) conn->data,
+		   get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
+
 login_task_data_alloc_fail:
 	kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
 		    sizeof(void*));
 login_task_alloc_fail:
-	iscsi_destroy_conn(cls_conn);
+	kfree(cls_conn);
 	return NULL;
 }
 EXPORT_SYMBOL_GPL(iscsi_conn_setup);
-- 
2.32.0