Commit e3c4abdb authored Sep 23, 2015 by Mark Yao

drm/rockchip: fix wrong pitch/size using on gem



args->pitch and args->size may not be set by userspace, sometimes
userspace only malloc args and not memset args to zero, then
args->pitch and args->size is random, it is very danger to use
pitch/size on gem.

pitch's type is u32, and min_pitch's type is int, example,
pitch is 0xffffffff, then pitch < min_pitch return true, then gem will
alloc very very big bufffer, it would eat all the memory and cause kernel
crash.

Stop using pitch/size from args, calc them from other args.

Signed-off-by: Mark Yao <mark.yao@rock-chips.com>

parent c9ad1d99

drivers/gpu/drm/rockchip/rockchip_drm_gem.c

+2 −7

Original line number	Diff line number	Diff line
		@@ -234,12 +234,7 @@ int rockchip_gem_dumb_create(struct drm_file *file_priv,
		/*
		* align to 64 bytes since Mali requires it.
		*/
		min_pitch = ALIGN(min_pitch, 64);

		if (args->pitch < min_pitch)
		args->pitch = min_pitch;

		if (args->size < args->pitch * args->height)
		args->pitch = ALIGN(min_pitch, 64);
		args->size = args->pitch * args->height;

		rk_obj = rockchip_gem_create_with_handle(file_priv, dev, args->size,