Commit f63f452e authored by Matthew Auld's avatar Matthew Auld Committed by Daniel Vetter
Browse files

drm/i915/gem: don't trust the dma_buf->size 



At least for the time being, we need to limit our object sizes such that
the number of pages can fit within a 32b signed int. It looks like we
should also apply the same restriction to any imported dma-buf.

Signed-off-by: default avatarMatthew Auld <matthew.auld@intel.com>
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20210122181514.541436-1-matthew.auld@intel.com


Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 041b7f07

drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c

+10 −0
Original line number Diff line number Diff line
@@ -244,6 +244,16 @@ struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev, 
		}

	}



	/*

	 * XXX: There is a prevalence of the assumption that we fit the

	 * object's page count inside a 32bit _signed_ variable. Let's document

	 * this and catch if we ever need to fix it. In the meantime, if you do

	 * spot such a local variable, please consider fixing!

	 */



	if (dma_buf->size >> PAGE_SHIFT > INT_MAX)

		return ERR_PTR(-E2BIG);



	/* need to attach */

	attach = dma_buf_attach(dma_buf, dev->dev);

	if (IS_ERR(attach))