[PATCH 3/3] regmap: duplicate the name string stored in regmap

Bartosz Golaszewski
2017-12-13T09:29:17Z

Currently we just copy over the pointer passed to regmap_init() in
the regmap config struct. To be on the safe side: duplicate the string
so that if an unaware user passes an address to a stack-allocated
buffer, we won't crash.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
---
drivers/base/regmap/regmap.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index a2a02ce58824..3952e5d7638a 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -672,6 +672,14 @@ struct regmap *__regmap_init(struct device *dev,
goto err;
}

+ if (config->name) {
+ map->name = kstrdup(config->name, GFP_KERNEL);
+ if (!map->name) {
+ ret = -ENOMEM;
+ goto err_map;
+ }
+ }
+
if (config->disable_locking) {
map->locking_disabled = true;
map->lock = map->unlock = regmap_lock_unlock_none;
@@ -763,7 +771,6 @@ struct regmap *__regmap_init(struct device *dev,
map->volatile_reg = config->volatile_reg;
map->precious_reg = config->precious_reg;
map->cache_type = config->cache_type;
- map->name = config->name;

spin_lock_init(&map->async_lock);
INIT_LIST_HEAD(&map->async_list);
@@ -1308,6 +1315,7 @@ void regmap_exit(struct regmap *map)
}
if (map->hwlock)
hwspin_lock_free(map->hwlock);
+ kfree(map->name);
kfree(map);
}
EXPORT_SYMBOL_GPL(regmap_exit);
--
2.15.1