media: uvcvideo: Fix double free in error path

BugLink: https://bugs.launchpad.net/bugs/2103829

commit c6ef3a7 upstream.

If the uvc_status_init() function fails to allocate the int_urb, it will
free the dev->status pointer but doesn't reset the pointer to NULL. This
results in the kfree() call in uvc_status_cleanup() trying to
double-free the memory. Fix it by resetting the dev->status pointer to
NULL after freeing it.

Fixes: a31a405 ("V4L/DVB:usbvideo:don't use part of buffer for USB transfer #4")
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Laurent Pinchart <[email protected]>
Reviewed by: Ricardo Ribalda <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Noah Wager <[email protected]>
Signed-off-by: Mehmet Basaran <[email protected]>

Author: pinchartl

drivers/media/usb/uvc/uvc_status.c

@@ -269,6 +269,7 @@ int uvc_status_init(struct uvc_device *dev)
 	dev->int_urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (!dev->int_urb) {
 		kfree(dev->status);
+		dev->status = NULL;
 		return -ENOMEM;
 	}