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>
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 7c50e58..de43194 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1133,6 +1133,11 @@
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) {