This is a note to let you know that I've just added the patch titled
drm: Check for lessee in DROP_MASTER ioctl
to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: drm-check-for-lessee-in-drop_master-ioctl.patch and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 761e05a702f5d537ffcca1ba933f9f0a968aa022 Mon Sep 17 00:00:00 2001
From: Keith Packard keithp@keithp.com Date: Thu, 18 Jan 2018 17:51:59 -0800 Subject: drm: Check for lessee in DROP_MASTER ioctl
From: Keith Packard keithp@keithp.com
commit 761e05a702f5d537ffcca1ba933f9f0a968aa022 upstream.
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 keithp@keithp.com Fixes: 2ed077e467ee ("drm: Add drm_object lease infrastructure [v5]") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch Link: https://patchwork.freedesktop.org/patch/msgid/20180119015159.1606-1-keithp@k... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/drm_auth.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/drivers/gpu/drm/drm_auth.c +++ b/drivers/gpu/drm/drm_auth.c @@ -230,6 +230,12 @@ int drm_dropmaster_ioctl(struct drm_devi 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:
Patches currently in stable-queue which might be from keithp@keithp.com are
queue-4.15/drm-check-for-lessee-in-drop_master-ioctl.patch