[PATCH 4.19 101/148] media: dvbdev: drop refcount on error path in dvb_device_open()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@linaro.org>

[ Upstream commit a2dd235df435a05d389240be748909ada91201d2 ]

If call to file->f_op->open() fails, then call dvb_device_put(dvbdev).

Fixes: 0fc044b2b5e2 ("media: dvbdev: adopts refcnt to avoid UAF")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/media/dvb-core/dvbdev.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/media/dvb-core/dvbdev.c b/drivers/media/dvb-core/dvbdev.c
index e103999711fc..b8335ede6626 100644
--- a/drivers/media/dvb-core/dvbdev.c
+++ b/drivers/media/dvb-core/dvbdev.c
@@ -113,6 +113,8 @@ static int dvb_device_open(struct inode *inode, struct file *file)
 			err = file->f_op->open(inode, file);
 		up_read(&minor_rwsem);
 		mutex_unlock(&dvbdev_mutex);
+		if (err)
+			dvb_device_put(dvbdev);
 		return err;
 	}
 fail:
-- 
2.43.0