drm/i915: fix integer overflow in i915_gem_do_execbuffer()

On 32-bit systems, a large args->num_cliprects from userspace via ioctl
may overflow the allocation size, leading to out-of-bounds access.

This vulnerability was introduced in commit 432e58ed ("drm/i915: Avoid
allocation for execbuffer object list").

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Xi Wang 2012-04-23 04:06:42 -04:00 committed by Daniel Vetter
parent ed8cd3b2cd
commit 44afb3a043
1 changed files with 5 additions and 0 deletions

View File

@ -1133,6 +1133,11 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
return -EINVAL;
}
if (args->num_cliprects > UINT_MAX / sizeof(*cliprects)) {
DRM_DEBUG("execbuf with %u cliprects\n",
args->num_cliprects);
return -EINVAL;
}
cliprects = kmalloc(args->num_cliprects * sizeof(*cliprects),
GFP_KERNEL);
if (cliprects == NULL) {