openwrtv4/target/linux/brcm2708/patches-4.4/0179-Protect-__release_resource-against-resources-without.patch

From 3006a98a1fe05d8a9ed22c5ffa3387bcffd3e6e7 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Fri, 13 Mar 2015 12:43:36 +0000
Subject: [PATCH 179/304] Protect __release_resource against resources without
 parents

Without this patch, removing a device tree overlay can crash here.

Signed-off-by: Phil Elwell <phil@raspberrypi.org>
---
 kernel/resource.c | 6 ++++++
 1 file changed, 6 insertions(+)

--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -237,6 +237,12 @@ static int __release_resource(struct res
 {
 	struct resource *tmp, **p;
 
+	if (!old->parent) {
+		WARN(old->sibling, "sibling but no parent");
+		if (old->sibling)
+			return -EINVAL;
+		return 0;
+	}
 	p = &old->parent->child;
 	for (;;) {
 		tmp = *p;