[PATCH] [media] stk-webcam: Fix use after free on disconnect

From: Dan Carpenter
Date: Fri Sep 22 2017 - 09:49:02 EST


We free the stk_camera device too early. It's allocate first in probe
and it should be freed last in stk_camera_disconnect().

Reported-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
Not tested but these bug reports seem surprisingly straight forward.
Thanks Andrey!

diff --git a/drivers/media/usb/stkwebcam/stk-webcam.c b/drivers/media/usb/stkwebcam/stk-webcam.c
index c0bba773db25..e748c976d967 100644
--- a/drivers/media/usb/stkwebcam/stk-webcam.c
+++ b/drivers/media/usb/stkwebcam/stk-webcam.c
@@ -1241,7 +1241,6 @@ static void stk_v4l_dev_release(struct video_device *vd)
if (dev->sio_bufs != NULL || dev->isobufs != NULL)
pr_err("We are leaking memory\n");
usb_put_intf(dev->interface);
- kfree(dev);
}

static const struct video_device stk_v4l_data = {
@@ -1391,6 +1390,7 @@ static void stk_camera_disconnect(struct usb_interface *interface)
video_unregister_device(&dev->vdev);
v4l2_ctrl_handler_free(&dev->hdl);
v4l2_device_unregister(&dev->v4l2_dev);
+ kfree(dev);
}

#ifdef CONFIG_PM