Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758047Ab3CNNjb (ORCPT ); Thu, 14 Mar 2013 09:39:31 -0400 Received: from mail-ve0-f171.google.com ([209.85.128.171]:56855 "EHLO mail-ve0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758032Ab3CNNj3 (ORCPT ); Thu, 14 Mar 2013 09:39:29 -0400 MIME-Version: 1.0 In-Reply-To: <1363265997-29023-1-git-send-email-chris@chris-wilson.co.uk> References: <1363265997-29023-1-git-send-email-chris@chris-wilson.co.uk> Date: Thu, 14 Mar 2013 15:39:28 +0200 Message-ID: Subject: Re: [PATCH] drm/i915: Sanity check incoming ioctl data for a NULL pointer From: Tommi Rantala To: Chris Wilson Cc: Daniel Vetter , David Airlie , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, LKML , Dave Jones Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2200 Lines: 53 2013/3/14 Chris Wilson : > In order to prevent a potential NULL deference with hostile userspace, > we need to check whether the ioctl was passed an invalid args pointer. > > Reported-by: Tommi Rantala > Link: http://lkml.kernel.org/r/CA+ydwtpuBvbwxbt-tdgPUvj1EU7itmCHo_2B3w13HkD5+jWKow@mail.gmail.com > Signed-off-by: Chris Wilson Thanks, looks good. I still see a flood of oopses from the other ioctls, so it's a bit difficult to test this patch properly. > --- > drivers/gpu/drm/i915/i915_gem_execbuffer.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > index 365e41a..9f5602e 100644 > --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c > +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c > @@ -1103,7 +1103,11 @@ i915_gem_execbuffer(struct drm_device *dev, void *data, > struct drm_i915_gem_exec_object2 *exec2_list = NULL; > int ret, i; > > - if (args->buffer_count < 1) { > + if (args == NULL) > + return -EINVAL; > + > + if (args->buffer_count < 1 || > + args->buffer_count > INT_MAX / sizeof(*exec2_list)) { > DRM_DEBUG("execbuf with %d buffers\n", args->buffer_count); > return -EINVAL; > } > @@ -1182,8 +1186,11 @@ i915_gem_execbuffer2(struct drm_device *dev, void *data, > struct drm_i915_gem_exec_object2 *exec2_list = NULL; > int ret; > > + if (args == NULL) > + return -EINVAL; > + > if (args->buffer_count < 1 || > - args->buffer_count > UINT_MAX / sizeof(*exec2_list)) { > + args->buffer_count > INT_MAX / sizeof(*exec2_list)) { > DRM_DEBUG("execbuf2 with %d buffers\n", args->buffer_count); > return -EINVAL; > } > -- > 1.7.10.4 > -- 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/