From da5c718ef46d0662f5f0bd112786587a3669119a Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Fri, 13 Mar 2015 12:43:36 +0000
Subject: [PATCH] Protect __release_resource against resources without parents

raspberrypi inclusion
category: feature
bugzilla: 50432

--------------------------------

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

Signed-off-by: Phil Elwell <phil@raspberrypi.org>
Signed-off-by: Fang Yafen <yafen@iscas.ac.cn>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
---
 kernel/resource.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/kernel/resource.c b/kernel/resource.c
index 3ae2f56cc79d..2f1a85c23e8b 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -214,6 +214,12 @@ static int __release_resource(struct resource *old, bool release_child)
 {
 	struct resource *tmp, **p, *chd;
 
+	if (!old->parent) {
+		WARN(old->sibling, "sibling but no parent");
+		if (old->sibling)
+			return -EINVAL;
+		return 0;
+	}
 	p = &old->parent->child;
 	for (;;) {
 		tmp = *p;
-- 
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