tty: vcc: Add check for kstrdup() in vcc_probe()

[ Upstream commit d81ffb8 ]

Add check for the return value of kstrdup() and return the error, if it
fails in order to avoid NULL pointer dereference.

Signed-off-by: Yi Yang <yiyang13@huawei.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230904035220.48164-1-yiyang13@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/tty/vcc.c

@@ -579,18 +579,22 @@ static int vcc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 		return -ENOMEM;
 
 	name = kstrdup(dev_name(&vdev->dev), GFP_KERNEL);
+	if (!name) {
+		rv = -ENOMEM;
+		goto free_port;
+	}
 
 	rv = vio_driver_init(&port->vio, vdev, VDEV_CONSOLE_CON, vcc_versions,
 			     ARRAY_SIZE(vcc_versions), NULL, name);
 	if (rv)
-		goto free_port;
+		goto free_name;
 
 	port->vio.debug = vcc_dbg_vio;
 	vcc_ldc_cfg.debug = vcc_dbg_ldc;
 
 	rv = vio_ldc_alloc(&port->vio, &vcc_ldc_cfg, port);
 	if (rv)
-		goto free_port;
+		goto free_name;
 
 	spin_lock_init(&port->lock);
 
@@ -624,6 +628,11 @@ static int vcc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 		goto unreg_tty;
 	}
 	port->domain = kstrdup(domain, GFP_KERNEL);
+	if (!port->domain) {
+		rv = -ENOMEM;
+		goto unreg_tty;
+	}
+
 
 	mdesc_release(hp);
 
@@ -653,8 +662,9 @@ static int vcc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 	vcc_table_remove(port->index);
 free_ldc:
 	vio_ldc_free(&port->vio);
-free_port:
+free_name:
 	kfree(name);
+free_port:
 	kfree(port);
 
 	return rv;