powerpc/prom: Avoid reference to potentially freed memory

[cascardo/linux.git] / arch / powerpc / kernel / prom.c

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index bef76c5..0b0a416 100644 (file)
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -783,14 +783,17 @@ void __init early_get_first_memblock_info(void *params, phys_addr_t *size)
 int of_get_ibm_chip_id(struct device_node *np)
 {
        of_node_get(np);
-       while(np) {
+       while (np) {
                struct device_node *old = np;
-               const __be32 *prop;
+               u32 chip_id;
 
-               prop = of_get_property(np, "ibm,chip-id", NULL);
-               if (prop) {
+               /*
+                * Skiboot may produce memory nodes that contain more than one
+                * cell in chip-id, we only read the first one here.
+                */
+               if (!of_property_read_u32(np, "ibm,chip-id", &chip_id)) {
                        of_node_put(np);
-                       return be32_to_cpup(prop);
+                       return chip_id;
                }
                np = of_get_parent(np);
                of_node_put(old);