[PATCH 4.4 51/70] ARM: hisi: handle of_iomap and fix missing of_node_put

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

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

From: Nicholas Mc Guire <hofrat@xxxxxxxxx>

[ Upstream commit d396cb185c0337aae5664b250cdd9a73f6eb1503 ]

Relying on an unchecked of_iomap() which can return NULL is problematic
here, an explicit check seems mandatory. Also the call to
of_find_compatible_node() returns a device node with refcount incremented
therefor an explicit of_node_put() is needed here.

Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
Fixes: commit 22bae4290457 ("ARM: hi3xxx: add hotplug support")
Signed-off-by: Wei Xu <xuwei5@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/arm/mach-hisi/hotplug.c |   19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

--- a/arch/arm/mach-hisi/hotplug.c
+++ b/arch/arm/mach-hisi/hotplug.c
@@ -148,13 +148,20 @@ static int hi3xxx_hotplug_init(void)
 	struct device_node *node;
 
 	node = of_find_compatible_node(NULL, NULL, "hisilicon,sysctrl");
-	if (node) {
-		ctrl_base = of_iomap(node, 0);
-		id = HI3620_CTRL;
-		return 0;
+	if (!node) {
+		id = ERROR_CTRL;
+		return -ENOENT;
 	}
-	id = ERROR_CTRL;
-	return -ENOENT;
+
+	ctrl_base = of_iomap(node, 0);
+	of_node_put(node);
+	if (!ctrl_base) {
+		id = ERROR_CTRL;
+		return -ENOMEM;
+	}
+
+	id = HI3620_CTRL;
+	return 0;
 }
 
 void hi3xxx_set_cpu(int cpu, bool enable)