FAILED: patch "[PATCH] drm: Don't call drm_for_each_crtc with a non-KMS driver" failed to apply to 4.8-stable tree

The patch below does not apply to the 4.8-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From: =?UTF-8?q?Michel=20D=C3=A4nzer?= <[email protected]>
Date: Wed, 30 Nov 2016 17:30:01 +0900
Subject: [PATCH] drm: Don't call drm_for_each_crtc with a non-KMS driver
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Fixes oops if userspace calls DRM_IOCTL_GET_CAP for
DRM_CAP_PAGE_FLIP_TARGET on a non-KMS device node. (Normal userspace
doesn't do that, discovered by syzkaller)

index 0ad2c47f808f..71c3473476c7 100644
@@ -254,10 +254,12 @@ static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_
 		req->value = dev->mode_config.async_page_flip;
 		break;
 	case DRM_CAP_PAGE_FLIP_TARGET:
-		req->value = 1;
-		drm_for_each_crtc(crtc, dev) {
-			if (!crtc->funcs->page_flip_target)
-				req->value = 0;
+		if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+			req->value = 1;
+			drm_for_each_crtc(crtc, dev) {
+				if (!crtc->funcs->page_flip_target)
+					req->value = 0;
+			}
 		}
 		break;
 	case DRM_CAP_CURSOR_WIDTH: