From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120504204226.438889916@linuxfoundation.org> Date: Fri, 04 May 2012 13:42:48 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Xi Wang , Chris Wilson , Daniel Vetter Subject: [ 24/75] drm/i915: fix integer overflow in i915_gem_execbuffer2() In-Reply-To: <20120504204258.GA12552@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xi Wang commit ed8cd3b2cd61004cab85380c52b1817aca1ca49b upstream. On 32-bit systems, a large args->buffer_count from userspace via ioctl may overflow the allocation size, leading to out-of-bounds access. This vulnerability was introduced in commit 8408c282 ("drm/i915: First try a normal large kmalloc for the temporary exec buffers"). Signed-off-by: Xi Wang Reviewed-by: Chris Wilson Signed-off-by: Daniel Vetter Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -1353,7 +1353,8 @@ i915_gem_execbuffer2(struct drm_device * struct drm_i915_gem_exec_object2 *exec2_list = NULL; int ret; - if (args->buffer_count < 1) { + if (args->buffer_count < 1 || + args->buffer_count > UINT_MAX / sizeof(*exec2_list)) { DRM_ERROR("execbuf2 with %d buffers\n", args->buffer_count); return -EINVAL; }