[PATCH 3.2 012/199] powerpc/ibmebus: Fix device reference leaks in sysfs interface

From: Ben Hutchings
Date: Fri Mar 10 2017 - 07:26:27 EST


3.2.87-rc1 review patch. If anyone has any objections, please let me know.

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

From: Johan Hovold <johan@xxxxxxxxxx>

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: 6bccf755ff53 ("[POWERPC] ibmebus: dynamic addition/removal of adapters, some code cleanup")
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/ibmebus.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- a/arch/powerpc/kernel/ibmebus.c
+++ b/arch/powerpc/kernel/ibmebus.c
@@ -261,6 +261,7 @@ static ssize_t ibmebus_store_probe(struc
const char *buf, size_t count)
{
struct device_node *dn = NULL;
+ struct device *dev;
char *path;
ssize_t rc = 0;

@@ -268,8 +269,10 @@ static ssize_t ibmebus_store_probe(struc
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;
@@ -305,6 +308,7 @@ static ssize_t ibmebus_store_remove(stru
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;