Patch "drm: Reject page_flip for !DRIVER_MODESET" has been added to the 4.4-stable tree

Patch "drm: Reject page_flip for !DRIVER_MODESET" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    drm: Reject page_flip for !DRIVER_MODESET

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-reject-page_flip-for-driver_modeset.patch
and it can be found in the queue-4.4 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 6f00975c619064a18c23fd3aced325ae165a73b9 Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Sat, 20 Aug 2016 12:22:11 +0200
Subject: drm: Reject page_flip for !DRIVER_MODESET

From: Daniel Vetter <daniel.vetter@ffwll.ch>

commit 6f00975c619064a18c23fd3aced325ae165a73b9 upstream.

Somehow this one slipped through, which means drivers without modeset
support can be oopsed (since those also don't call
drm_mode_config_init, which means the crtc lookup will chase an
uninitalized idr).

Reported-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/drm_crtc.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -5231,6 +5231,9 @@ int drm_mode_page_flip_ioctl(struct drm_
 	unsigned long flags;
 	int ret = -EINVAL;
 
+	if (!drm_core_check_feature(dev, DRIVER_MODESET))
+		return -EINVAL;
+
 	if (page_flip->flags & ~DRM_MODE_PAGE_FLIP_FLAGS ||
 	    page_flip->reserved != 0)
 		return -EINVAL;


Patches currently in stable-queue which might be from daniel.vetter@ffwll.ch are

queue-4.4/0078-drm-atomic-Do-not-unset-crtc-when-an-encoder-is-stol.patch
queue-4.4/drm-reject-page_flip-for-driver_modeset.patch
queue-4.4/0130-drm-i915-Only-ignore-eDP-ports-that-are-connected.patch
queue-4.4/0111-drm-Balance-error-path-for-GEM-handle-allocation.patch
queue-4.4/0087-drm-i915-Fix-hpd-live-status-bits-for-g4x.patch