[PATCH 3.13 057/105] regmap: debugfs: fix possbile NULL pointer dereference

Kamal Mostafa
2014-10-27T18:59:02Z

From: Xiubo Li <Li.Xiubo@freescale.com>

commit 2c98e0c1cc6b8e86f1978286c3d4e0769ee9d733 upstream.

If 'map->dev' is NULL and there will lead dev_name() to be NULL pointer
dereference. So before dev_name(), we need to have check of the map->dev
pionter.

We also should make sure that the 'name' pointer shouldn't be NULL for
debugfs_create_dir(). So here using one default "dummy" debugfs name when
the 'name' pointer and 'map->dev' are both NULL.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
drivers/base/regmap/regmap-debugfs.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
index f89d382..004e132 100644
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -473,6 +473,7 @@ void regmap_debugfs_init(struct regmap *map, const char *name)
{
struct rb_node *next;
struct regmap_range_node *range_node;
+ const char *devname = "dummy";

/* If we don't have the debugfs root yet, postpone init */
if (!regmap_debugfs_root) {
@@ -491,12 +492,15 @@ void regmap_debugfs_init(struct regmap *map, const char *name)
INIT_LIST_HEAD(&map->debugfs_off_cache);
mutex_init(&map->cache_lock);

+ if (map->dev)
+ devname = dev_name(map->dev);
+
if (name) {
map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
- dev_name(map->dev), name);
+ devname, name);
name = map->debugfs_name;
} else {
- name = dev_name(map->dev);
+ name = devname;
}

map->debugfs = debugfs_create_dir(name, regmap_debugfs_root);
--
1.9.1