Commit 3faf4304 authored Oct 30, 2014 by Thierry Reding Committed by Greg Kroah-Hartman Jan 08, 2015

drm/tegra: gem: dumb: pitch and size are outputs

commit dc6057ecb39edb34b0461ca55382094410bd257a upstream.

When creating a dumb buffer object using the DRM_IOCTL_MODE_CREATE_DUMB
IOCTL, only the width, height, bpp and flags parameters are inputs. The
caller is not guaranteed to zero out or set handle, pitch and size, so
the driver must not treat these values as possible inputs.

Fixes a bug where running the Weston compositor on Tegra DRM would cause
an attempt to allocate a 3 GiB framebuffer to be allocated.

Fixes: de2ba664 ("gpu: host1x: drm: Add memory manager and fb")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent f324cda6

drivers/gpu/drm/tegra/gem.c

+3 −7

Original line number	Diff line number	Diff line
		@@ -259,15 +259,11 @@ void tegra_bo_free_object(struct drm_gem_object *gem)
		int tegra_bo_dumb_create(struct drm_file file, struct drm_device drm,
		struct drm_mode_create_dumb *args)
		{
		int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
		unsigned int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
		struct tegra_drm *tegra = drm->dev_private;
		struct tegra_bo *bo;

		min_pitch = round_up(min_pitch, tegra->pitch_align);
		if (args->pitch < min_pitch)
		args->pitch = min_pitch;

		if (args->size < args->pitch * args->height)
		args->pitch = round_up(min_pitch, tegra->pitch_align);
		args->size = args->pitch * args->height;

		bo = tegra_bo_create_with_handle(file, drm, args->size, 0,