[PATCH 4/4] of: detect invalid phandle in overlay

From: frowand . list
Date: Fri Apr 14 2017 - 23:56:44 EST


From: Frank Rowand <frank.rowand@xxxxxxxx>

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

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

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index ca0b85f5deb1..20ab49d2f7a4 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -130,6 +130,10 @@ 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@xxxxxxxx>