From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932756AbeASB6l (ORCPT ); Thu, 18 Jan 2018 20:58:41 -0500 Received: from home.keithp.com ([63.227.221.253]:45512 "EHLO elaine.keithp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755535AbeASBwM (ORCPT ); Thu, 18 Jan 2018 20:52:12 -0500 From: Keith Packard To: linux-kernel@vger.kernel.org, Dave Airlie , Daniel Vetter Cc: Keith Packard , dri-devel@lists.freedesktop.org Subject: [PATCH] drm: Check for lessee in DROP_MASTER ioctl Date: Thu, 18 Jan 2018 17:51:59 -0800 Message-Id: <20180119015159.1606-1-keithp@keithp.com> X-Mailer: git-send-email 2.15.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Don't let a lessee control what the current DRM master is set to; that's the job of the "real" master. Otherwise, the lessee would disable all access to master operations for the owner and all lessees under it. This matches the same check made in the SET_MASTER ioctl. Signed-off-by: Keith Packard --- drivers/gpu/drm/drm_auth.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c index aad468d170a7..d9c0f7573905 100644 --- a/drivers/gpu/drm/drm_auth.c +++ b/drivers/gpu/drm/drm_auth.c @@ -230,6 +230,12 @@ int drm_dropmaster_ioctl(struct drm_device *dev, void *data, if (!dev->master) goto out_unlock; + if (file_priv->master->lessor != NULL) { + DRM_DEBUG_LEASE("Attempt to drop lessee %d as master\n", file_priv->master->lessee_id); + ret = -EINVAL; + goto out_unlock; + } + ret = 0; drm_drop_master(dev, file_priv); out_unlock: -- 2.15.1