drm/i915: Check for NULL atomic state in intel_crtc_disable_noatomic()

commit 6d1d427a4e24c403b4adf928d61994bdaa0ca03a upstream.

In intel_crtc_disable_noatomic(), bail on a failure to allocate an
atomic state to avoid a NULL pointer dereference.

Fixes: 4a80655827af ("drm/i915: Pass atomic state to crtc enable/disable functions")
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1484922525-6131-4-git-send-email-ander.conselvan.de.oliveira@intel.com
(cherry picked from commit 31bb2ef97ea9db343348f9b5ccaa9bb6f48fc655)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 944e067a9f28..8079e5b380cb 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6869,6 +6869,12 @@ static void intel_crtc_disable_noatomic(struct drm_crtc *crtc)
         }
 
         state = drm_atomic_state_alloc(crtc->dev);
+        if (!state) {
+                DRM_DEBUG_KMS("failed to disable [CRTC:%d:%s], out of memory",
+                              crtc->base.id, crtc->name);
+                return;
+        }
+
         state->acquire_ctx = crtc->dev->mode_config.acquire_ctx;
 
         /* Everything's already locked, -EDEADLK can't happen. */