[PATCH] of: overlay: add_changeset_property() memory leak

frowand.list
2019-11-21T19:17:35Z

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

No changeset entries are created for #address-cells and #size-cells
properties, but the duplicated properties are never freed. This
results in a memory leak which is detected by kmemleak:

unreferenced object 0x85887180 (size 64):
backtrace:
kmem_cache_alloc_trace+0x1fb/0x1fc
__of_prop_dup+0x25/0x7c
add_changeset_property+0x17f/0x370
build_changeset_next_level+0x29/0x20c
of_overlay_fdt_apply+0x32b/0x6b4
...

Fixes: 6f75118800acf77f8 ("of: overlay: validate overlay properties #address-cells and #size-cells")
Reported-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
---
drivers/of/overlay.c | 37 ++++++++++++++++++++-----------------
1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index c423e94baf0f..9617b7df7c4d 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -305,7 +305,6 @@ static int add_changeset_property(struct overlay_changeset *ovcs,
{
struct property *new_prop = NULL, *prop;
int ret = 0;
- bool check_for_non_overlay_node = false;

if (target->in_livetree)
if (!of_prop_cmp(overlay_prop->name, "name") ||
@@ -318,6 +317,25 @@ static int add_changeset_property(struct overlay_changeset *ovcs,
else
prop = NULL;

+ if (prop) {
+ if (!of_prop_cmp(prop->name, "#address-cells")) {
+ if (!of_prop_val_eq(prop, overlay_prop)) {
+ pr_err("ERROR: changing value of #address-cells is not allowed in %pOF\n",
+ target->np);
+ ret = -EINVAL;
+ }
+ return ret;
+
+ } else if (!of_prop_cmp(prop->name, "#size-cells")) {
+ if (!of_prop_val_eq(prop, overlay_prop)) {
+ pr_err("ERROR: changing value of #size-cells is not allowed in %pOF\n",
+ target->np);
+ ret = -EINVAL;
+ }
+ return ret;
+ }
+ }
+
if (is_symbols_prop) {
if (prop)
return -EINVAL;
@@ -330,33 +348,18 @@ static int add_changeset_property(struct overlay_changeset *ovcs,
return -ENOMEM;

if (!prop) {
- check_for_non_overlay_node = true;
if (!target->in_livetree) {
new_prop->next = target->np->deadprops;
target->np->deadprops = new_prop;
}
ret = of_changeset_add_property(&ovcs->cset, target->np,
new_prop);
- } else if (!of_prop_cmp(prop->name, "#address-cells")) {
- if (!of_prop_val_eq(prop, new_prop)) {
- pr_err("ERROR: changing value of #address-cells is not allowed in %pOF\n",
- target->np);
- ret = -EINVAL;
- }
- } else if (!of_prop_cmp(prop->name, "#size-cells")) {
- if (!of_prop_val_eq(prop, new_prop)) {
- pr_err("ERROR: changing value of #size-cells is not allowed in %pOF\n",
- target->np);
- ret = -EINVAL;
- }
} else {
- check_for_non_overlay_node = true;
ret = of_changeset_update_property(&ovcs->cset, target->np,
new_prop);
}

- if (check_for_non_overlay_node &&
- !of_node_check_flag(target->np, OF_OVERLAY))
+ if (!of_node_check_flag(target->np, OF_OVERLAY))
pr_err("WARNING: memory leak will occur if overlay removed, property: %pOF/%s\n",
target->np, new_prop->name);

--
Frank Rowand <frank.rowand@sony.com>