From: Xi Wang Date: Mon, 23 Apr 2012 04:06:42 -0400 Message-Id: <1335168402-25174-2-git-send-email-xi.wang@gmail.com> Subject: [PATCH v2 2/2] 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 Cc: Chris Wilson Cc: stable@vger.kernel.org --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) 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 @@ 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) { -- 1.7.5.4