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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        syzbot+77b432d57c4791183ed4@syzkaller.appspotmail.com,
        Dongliang Mu <mudongliangabcd@gmail.com>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Mauro Carvalho Chehab <mchehab@kernel.org>
Subject: [PATCH 4.9 23/31] media: pvrusb2: fix memory leak in pvr_probe
Date:   Fri,  2 Sep 2022 14:18:49 +0200
Message-Id: <20220902121357.611984352@linuxfoundation.org>
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From: Dongliang Mu <mudongliangabcd@gmail.com>

commit 945a9a8e448b65bec055d37eba58f711b39f66f0 upstream.

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@syzkaller.appspotmail.com
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/media/usb/pvrusb2/pvrusb2-hdw.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
+++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
@@ -2656,6 +2656,7 @@ struct pvr2_hdw *pvr2_hdw_create(struct
 		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);