linux-kernel - [PATCH] pvrusb2: fix memory leak in pvr

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Message-Id: <20220609073528.4767-1-dzm91@hust.edu.cn>
Date:   Thu,  9 Jun 2022 15:35:28 +0800
From:   Dongliang Mu <dzm91@...t.edu.cn>
To:     Mike Isely <isely@...ox.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>
Cc:     Dongliang Mu <mudongliangabcd@...il.com>,
        syzbot+77b432d57c4791183ed4@...kaller.appspotmail.com,
        linux-media@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] pvrusb2: fix memory leak in pvr_probe

From: Dongliang Mu <mudongliangabcd@...il.com>

The error handling code in pvr2_hdw_create forgets to unregister the
v4l2 device. When pvr2_hdw_create returns back to pvr2_context_create,
it calls pvr2_context_destroy to destroy context, but mp->hdw is NULL,
which leads to that pvr2_hdw_destroy directly returns.

Fix this by adding v4l2_device_unregister to decrease the refcount of
usb interface.

Reported-by: syzbot+77b432d57c4791183ed4@...kaller.appspotmail.com
Signed-off-by: Dongliang Mu <mudongliangabcd@...il.com>
---
 drivers/media/usb/pvrusb2/pvrusb2-hdw.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
index a9666373af6b..92d6db1ad00f 100644
--- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
+++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
@@ -2610,6 +2610,7 @@ struct pvr2_hdw *pvr2_hdw_create(struct usb_interface *intf,
 		del_timer_sync(&hdw->encoder_run_timer);
 		del_timer_sync(&hdw->encoder_wait_timer);
 		flush_work(&hdw->workpoll);
+		v4l2_device_unregister(&hdw->v4l2_dev);
 		usb_free_urb(hdw->ctl_read_urb);
 		usb_free_urb(hdw->ctl_write_urb);
 		kfree(hdw->ctl_read_buffer);
-- 
2.25.1