Don't allow a mismatch between obj->base.size/vma->size and the actual number of pages for the backing store, which is limited to INT_MAX pages. v2: document what are missing before we can safely drop the limit check Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx> Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index e5558af111e2..b64b0f383a56 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -769,6 +769,23 @@ i915_gem_userptr_ioctl(struct drm_device *dev, I915_USERPTR_UNSYNCHRONIZED)) return -EINVAL; + /* + * 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! + * + * Aside from our own locals (for which we have no excuse!): + * - sg_table embeds unsigned int for num_pages + * - get_user_pages*() mixed ints with longs + */ + + if (args->user_size >> PAGE_SHIFT > INT_MAX) + return -E2BIG; + + if (overflows_type(args->user_size, obj->base.size)) + return -E2BIG; + if (!args->user_size) return -EINVAL; -- 2.20.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
