Re: [Intel-gfx] [PATCH] drm/i915: Sanity check incoming ioctl data for a NULL pointer

On Sun, Mar 17, 2013 at 08:50:03PM +0100, Daniel Vetter wrote:

On Sat, Mar 16, 2013 at 11:19 AM, Chris Wilson chris@chris-wilson.co.uk wrote:

...

If *userspace* doesn't request either IOC_IN | IOC_OUT in their ioctl command (which are seperate from the ioctl number), then kdata is set to NULL.

Doesn't that mean that we need these checks everywhere? Or at least a fixup in drm core proper?

That's my conclusion. We either add a flag to ask drm_ioctl to prevent passing NULL pointers (as the existing behaviour may be useful somewhere, and I have not checked all callees) or saturate our callbacks with NULL checks. -Chris