Delivered-To: jwboyer@gmail.com Received: by 10.76.169.233 with SMTP id ah9csp107244oac; Mon, 11 Mar 2013 17:32:43 -0700 (PDT) X-Received: by 10.68.195.70 with SMTP id ic6mr32376980pbc.60.1363048363048; Mon, 11 Mar 2013 17:32:43 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id xm3si25923071pbc.196.2013.03.11.17.32.12; Mon, 11 Mar 2013 17:32:43 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mail=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754633Ab3CLAbx (ORCPT + 99 others); Mon, 11 Mar 2013 20:31:53 -0400 Received: from smtp.outflux.net ([198.145.64.163]:48630 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754446Ab3CLAbx (ORCPT ); Mon, 11 Mar 2013 20:31:53 -0400 Received: from www.outflux.net (serenity-end.outflux.net [10.2.0.2]) by vinyl.outflux.net (8.14.4/8.14.4/Debian-2ubuntu2) with ESMTP id r2C0VjYO004342; Mon, 11 Mar 2013 17:31:45 -0700 Date: Mon, 11 Mar 2013 17:31:45 -0700 From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Daniel Vetter , David Airlie , dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, Julien Tinnes , marcheu@chromium.org Subject: [PATCH v3] drm/i915: bounds check execbuffer relocation count Message-ID: <20130312003145.GA28993@www.outflux.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-MIMEDefang-Filter: outflux$Revision: 1.316 $ X-HELO: www.outflux.net X-Scanned-By: MIMEDefang 2.71 on 10.2.0.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is possible to wrap the counter used to allocate the buffer for relocation copies. This could lead to heap writing overflows. CVE-2013-0913 v3: collapse test, improve comment v2: move check into validate_exec_list Signed-off-by: Kees Cook Reported-by: Pinkie Pie Cc: stable@vger.kernel.org --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index b3a40ee..094ba41 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -732,6 +732,8 @@ validate_exec_list(struct drm_i915_gem_exec_object2 *exec, int count) { int i; + int relocs_total = 0; + int relocs_max = INT_MAX / sizeof(struct drm_i915_gem_relocation_entry); for (i = 0; i < count; i++) { char __user *ptr = (char __user *)(uintptr_t)exec[i].relocs_ptr; @@ -740,10 +742,13 @@ validate_exec_list(struct drm_i915_gem_exec_object2 *exec, if (exec[i].flags & __EXEC_OBJECT_UNKNOWN_FLAGS) return -EINVAL; - /* First check for malicious input causing overflow */ - if (exec[i].relocation_count > - INT_MAX / sizeof(struct drm_i915_gem_relocation_entry)) + /* First check for malicious input causing overflow in + * the worst case where we need to allocate the entire + * relocation tree as a single array. + */ + if (exec[i].relocation_count > relocs_max - relocs_total) return -EINVAL; + relocs_total += exec[i].relocation_count; length = exec[i].relocation_count * sizeof(struct drm_i915_gem_relocation_entry); -- 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/