Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932535AbdDGHRL (ORCPT ); Fri, 7 Apr 2017 03:17:11 -0400 Received: from mail-wr0-f194.google.com ([209.85.128.194]:33566 "EHLO mail-wr0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753038AbdDGHRD (ORCPT ); Fri, 7 Apr 2017 03:17:03 -0400 Date: Fri, 7 Apr 2017 09:16:59 +0200 From: Daniel Vetter To: Jeffy Chen Cc: linux-kernel@vger.kernel.org, briannorris@chromium.org, dianders@chromium.org, tfiga@chromium.org, dri-devel@lists.freedesktop.org, zyw@rock-chips.com, Daniel Vetter Subject: Re: [PATCH v5 12/12] drm/drm_ioctl.c: Break ioctl when drm device not registered Message-ID: <20170407071659.hwf5f7jf2bjjdata@phenom.ffwll.local> Mail-Followup-To: Jeffy Chen , linux-kernel@vger.kernel.org, briannorris@chromium.org, dianders@chromium.org, tfiga@chromium.org, dri-devel@lists.freedesktop.org, zyw@rock-chips.com, Daniel Vetter References: <1491481885-13775-1-git-send-email-jeffy.chen@rock-chips.com> <1491481885-13775-13-git-send-email-jeffy.chen@rock-chips.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1491481885-13775-13-git-send-email-jeffy.chen@rock-chips.com> X-Operating-System: Linux phenom 4.9.0-2-amd64 User-Agent: NeoMutt/20170306 (1.8.0) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1492 Lines: 52 On Thu, Apr 06, 2017 at 08:31:25PM +0800, Jeffy Chen wrote: > After unbinding drm, the user space may still owns the drm dev fd, > and may still be able to call drm ioctl. > > Add a sanity check here to prevent that from happening. > > Signed-off-by: Jeffy Chen > --- > > Changes in v5: None > Changes in v4: None > Changes in v3: None > Changes in v2: None > > drivers/gpu/drm/drm_ioctl.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c > index 7d6deaa..15beb11 100644 > --- a/drivers/gpu/drm/drm_ioctl.c > +++ b/drivers/gpu/drm/drm_ioctl.c > @@ -674,7 +674,7 @@ long drm_ioctl(struct file *filp, > > dev = file_priv->minor->dev; > > - if (drm_device_is_unplugged(dev)) > + if (drm_device_is_unplugged(dev) || !dev->registered) Shouldn't we instead automatically unplug the device in drm_dev_unregister, instead of sprinkling tons of drm_device_is_unplugged || !registered all over the place? That should catch a few more issues where userspace might creep into the driver after unregistering ... -Daniel > return -ENODEV; > > is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END; > -- > 2.1.4 > > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch