powerpc/ibmebus: Fix device reference leaks in sysfs interface

commit fe0f3168169f7c34c29b0cf0c489f126a7f29643 upstream.

Make sure to drop any reference taken by bus_find_device() in the sysfs
callbacks that are used to create and destroy devices based on
device-tree entries.

Fixes: 6bccf75 ("[POWERPC] ibmebus: dynamic addition/removal of adapters, some code cleanup")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: jhovold

arch/powerpc/kernel/ibmebus.c

@@ -266,15 +266,18 @@ static ssize_t ibmebus_store_probe(struct bus_type *bus,
 				   const char *buf, size_t count)
 {
 	struct device_node *dn = NULL;
+	struct device *dev;
 	char *path;
 	ssize_t rc = 0;
 
 	path = ibmebus_chomp(buf, count);
 	if (!path)
 		return -ENOMEM;
 
-	if (bus_find_device(&ibmebus_bus_type, NULL, path,
-			    ibmebus_match_path)) {
+	dev = bus_find_device(&ibmebus_bus_type, NULL, path,
+			      ibmebus_match_path);
+	if (dev) {
+		put_device(dev);
 		printk(KERN_WARNING "%s: %s has already been probed\n",
 		       __func__, path);
 		rc = -EEXIST;
@@ -311,6 +314,7 @@ static ssize_t ibmebus_store_remove(struct bus_type *bus,
 	if ((dev = bus_find_device(&ibmebus_bus_type, NULL, path,
 				   ibmebus_match_path))) {
 		of_device_unregister(to_platform_device(dev));
+		put_device(dev);
 
 		kfree(path);
 		return count;