[PATCH 3/3] of: detect invalid phandle in overlay

[frowand.list@gmail.com]

From: Frank Rowand <frank.rowand@sony.com>

Overlays are not allowed to modify phandle values of previously existing
nodes because there is no information available to allow fixup up of
properties that use the previously existing phandle.

Signed-off-by: Frank Rowand <frank.rowand@sony.com>
---
 drivers/of/overlay.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index 7827786718d8..c0e4ee1cd1ba 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -132,6 +132,10 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov,
 	/* NOTE: Multiple mods of created nodes not supported */
 	tchild = of_get_child_by_name(target, cname);
 	if (tchild != NULL) {
+		/* new overlay phandle value conflicts with existing value */
+		if (child->phandle)
+			return -EINVAL;
+
 		/* apply overlay recursively */
 		ret = of_overlay_apply_one(ov, tchild, child);
 		of_node_put(tchild);
-- 
Frank Rowand <frank.rowand@sony.com>