drm/nouveau/nvif: allow userspace access to its own client object

Regression from "abi16: implement limited interoperability with
usif/nvif".

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_usif.c b/drivers/gpu/drm/nouveau/nouveau_usif.c
index 89dc4ce..6ae1b34 100644
--- a/drivers/gpu/drm/nouveau/nouveau_usif.c
+++ b/drivers/gpu/drm/nouveau/nouveau_usif.c
@@ -313,7 +313,10 @@
 	if (nvif_unpack(argv->v0, 0, 0, true)) {
 		/* block access to objects not created via this interface */
 		owner = argv->v0.owner;
-		argv->v0.owner = NVDRM_OBJECT_USIF;
+		if (argv->v0.object == 0ULL)
+			argv->v0.owner = NVDRM_OBJECT_ANY; /* except client */
+		else
+			argv->v0.owner = NVDRM_OBJECT_USIF;
 	} else
 		goto done;