From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752302AbdLFU26 (ORCPT ); Wed, 6 Dec 2017 15:28:58 -0500 Received: from mail-pf0-f193.google.com ([209.85.192.193]:42975 "EHLO mail-pf0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751847AbdLFU2y (ORCPT ); Wed, 6 Dec 2017 15:28:54 -0500 X-Google-Smtp-Source: AGs4zMY6wt96o1c1UW0aTR/sbkzZ+DWpeSypZzgJqTL1tSY5FcrCqa+M6HAq+9M8G0piAZ5dnQeFvA== Date: Wed, 6 Dec 2017 12:28:50 -0800 From: Kees Cook To: Jason Ekstrand Cc: Chris Wilson , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH] drm/i915: Use copy_from_user() in fence copying Message-ID: <20171206202850.GA38365@beast> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There's no good reason to separate the access_ok() from the copy, especially since the access_ok() size is hard-coded instead of using sizeof(). Instead, just use copy_from_user() directly. Fixes: cf6e7bac6357 ("drm/i915: Add support for drm syncobjs") Cc: Jason Ekstrand Cc: Chris Wilson Signed-off-by: Kees Cook --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 435ed95df144..1da703213b17 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -2087,8 +2087,6 @@ get_fence_array(struct drm_i915_gem_execbuffer2 *args, return ERR_PTR(-EINVAL); user = u64_to_user_ptr(args->cliprects_ptr); - if (!access_ok(VERIFY_READ, user, nfences * 2 * sizeof(u32))) - return ERR_PTR(-EFAULT); fences = kvmalloc_array(args->num_cliprects, sizeof(*fences), __GFP_NOWARN | GFP_KERNEL); @@ -2099,7 +2097,7 @@ get_fence_array(struct drm_i915_gem_execbuffer2 *args, struct drm_i915_gem_exec_fence fence; struct drm_syncobj *syncobj; - if (__copy_from_user(&fence, user++, sizeof(fence))) { + if (copy_from_user(&fence, user++, sizeof(fence))) { err = -EFAULT; goto err; } -- 2.7.4 -- Kees Cook Pixel Security