[PATCH] media: dvb-usb: fix refcount leak in dvb_usb_adapter_frontend_init()

[Wentao Liang]

After all frontends are registered via dvb_register_frontend(),
if dvb_create_media_graph() or dvb_usb_media_device_register()
fails, the function returns directly without calling
dvb_unregister_frontend() and dvb_frontend_detach() for each
frontend. This leaves them with a leaked reference count.

The caller's error path calls dvb_usb_adapter_dvb_exit() which
does not handle frontend cleanup. Add the missing cleanup by
calling dvb_usb_adapter_frontend_exit() on the error path.

Fixes: 9f80679511b0 ("[media] usb: check media device errors")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Wentao Liang <vulab@xxxxxxxxxxx>
---
 drivers/media/usb/dvb-usb/dvb-usb-dvb.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/dvb-usb/dvb-usb-dvb.c b/drivers/media/usb/dvb-usb/dvb-usb-dvb.c
index 029dad86a059..923f25ccb1e8 100644
--- a/drivers/media/usb/dvb-usb/dvb-usb-dvb.c
+++ b/drivers/media/usb/dvb-usb/dvb-usb-dvb.c
@@ -326,10 +326,16 @@ int dvb_usb_adapter_frontend_init(struct dvb_usb_adapter *adap)
 
 	ret = dvb_create_media_graph(&adap->dvb_adap, true);
 	if (ret)
-		return ret;
+		goto err_fe_cleanup;
 
 	ret = dvb_usb_media_device_register(adap);
+	if (ret)
+		goto err_fe_cleanup;
+
+	return ret;
 
+err_fe_cleanup:
+	dvb_usb_adapter_frontend_exit(adap);
 	return ret;
 }
 
-- 
2.34.1