of: overlay: add_changeset_property() memory leak

commit 637392a8506a3a7dd24ab9094a14f7522adb73b4 upstream.

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: 6f75118800ac ("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>
Tested-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index c423e94..9617b7d 100644 (file)
--- 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);