From 2c98e0c1cc6b8e86f1978286c3d4e0769ee9d733 Mon Sep 17 00:00:00 2001 From: Xiubo Li Date: Sun, 28 Sep 2014 11:35:25 +0800 Subject: [PATCH 1/2] regmap: debugfs: fix possbile NULL pointer dereference 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 Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- 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 45d812c0ea77..bdd88708e4d6 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); From 18c0301f9898feaac38135b2cea476bb606830e3 Mon Sep 17 00:00:00 2001 From: Markus Pargmann Date: Mon, 8 Sep 2014 08:43:37 +0200 Subject: [PATCH 2/2] regmap: Fix debugfs-file 'registers' mode The macro "REGMAP_ALLOW_WRITE_DEBUGFS" can be used to enable write support on the registers file in the debugfs. The mode of the file is fixed to 0400 so it is not possible to write the file ever. This patch fixes the mode by setting it to the correct value depending on the macro. Signed-off-by: Markus Pargmann Signed-off-by: Mark Brown --- drivers/base/regmap/regmap-debugfs.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c index bdd88708e4d6..a88cbd42edf0 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -516,7 +516,14 @@ void regmap_debugfs_init(struct regmap *map, const char *name) map, ®map_reg_ranges_fops); if (map->max_register || regmap_readable(map, 0)) { - debugfs_create_file("registers", 0400, map->debugfs, + umode_t registers_mode; + + if (IS_ENABLED(REGMAP_ALLOW_WRITE_DEBUGFS)) + registers_mode = 0600; + else + registers_mode = 0400; + + debugfs_create_file("registers", registers_mode, map->debugfs, map, ®map_map_fops); debugfs_create_file("access", 0400, map->debugfs, map, ®map_access_fops);