Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754153Ab3CKT1W (ORCPT ); Mon, 11 Mar 2013 15:27:22 -0400 Received: from smtp.outflux.net ([198.145.64.163]:41330 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754054Ab3CKT1T (ORCPT ); Mon, 11 Mar 2013 15:27:19 -0400 Date: Mon, 11 Mar 2013 12:27:16 -0700 From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Daniel Vetter , David Airlie , dri-devel@lists.freedesktop.org Subject: [PATCH] drm/i915: bounds check execbuffer relocations Message-ID: <20130311192716.GA18244@www.outflux.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1638 Lines: 51 It is possible to wrap the counter used to allocate the buffer for relocation copies. This could lead to heap writing overflows. Signed-off-by: Kees Cook Reported-by: Pinkie Pie Cc: stable@vger.kernel.org --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 752e399..62eaa99 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -585,7 +585,8 @@ i915_gem_execbuffer_relocate_slow(struct drm_device *dev, struct drm_i915_gem_object *obj; bool need_relocs; int *reloc_offset; - int i, total, ret; + int ret; + unsigned int i, total; int count = args->buffer_count; /* We may process another execbuffer during the unlock... */ @@ -600,8 +601,13 @@ i915_gem_execbuffer_relocate_slow(struct drm_device *dev, mutex_unlock(&dev->struct_mutex); total = 0; - for (i = 0; i < count; i++) + for (i = 0; i < count; i++) { + if (exec[i].relocation_count > UINT_MAX - total) { + mutex_lock(&dev->struct_mutex); + return -ENOMEM; + } total += exec[i].relocation_count; + } reloc_offset = drm_malloc_ab(count, sizeof(*reloc_offset)); reloc = drm_malloc_ab(total, sizeof(*reloc)); -- 1.7.9.5 -- Kees Cook Chrome OS Security -- 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/