Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758038Ab2EIGLs (ORCPT ); Wed, 9 May 2012 02:11:48 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:39103 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756546Ab2EIFxb (ORCPT ); Wed, 9 May 2012 01:53:31 -0400 Message-Id: <20120509055045.040760162@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Wed, 09 May 2012 06:52:20 +0100 From: Ben Hutchings 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: [ 111/167] [PATCH] drm/i915: fix integer overflow in i915_gem_execbuffer2() In-Reply-To: <20120509055029.588587017@decadent.org.uk> X-SA-Exim-Connect-IP: 192.168.4.185 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1648 Lines: 44 3.2-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 [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index f51a696..7c50e58 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -1404,7 +1404,8 @@ i915_gem_execbuffer2(struct drm_device *dev, void *data, 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; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/