linux/drivers/gpu
Chris Wilson 01d3434a56 drm: Don't overwrite user ioctl arg unless requested
Currently, we completely ignore the user when it comes to the in/out
direction of the ioctl argument, as we simply cannot trust userspace.
(For example, they might request a copy of the modified ioctl argument
when the driver is not expecting such and so leak kernel stack.)
However, blindly copying over the target address may also lead to a
spurious EFAULT, and a failure after the ioctl was completed
successfully. This is important in order to avoid an ABI break when
extending an ioctl from IOR to IORW. Similar to how we only copy the
intersection of the kernel arg size and the user arg size, we only want
to copy back the kernel arg data iff both the kernel and userspace
request the copy.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1468335590-21023-1-git-send-email-chris@chris-wilson.co.uk
2016-07-14 10:12:50 +02:00
..
drm drm: Don't overwrite user ioctl arg unless requested 2016-07-14 10:12:50 +02:00
host1x remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00
ipu-v3 drm/imx: Match imx-ipuv3-crtc components using device node in platform data 2016-05-23 12:35:11 +02:00
vga vga_switcheroo: Sphinxify docs 2016-07-12 16:14:36 +02:00
Makefile