From 12ae3808c160b7be0de3c633ac4cbe8c5f2937bf Mon Sep 17 00:00:00 2001 From: David Lechner Date: Mon, 19 Feb 2018 15:43:01 -0600 Subject: [PATCH] regmap: Allow missing device in regmap_name_read_file() This fixes a possible NULL pointer dereference oops in regmap_name_read_file() when the regmap does not have a device associated with it. For example syscon regmaps retrieved with syscon_regmap_lookup_by_compatible() don't have a device. Signed-off-by: David Lechner Signed-off-by: Mark Brown --- drivers/base/regmap/regmap-debugfs.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c index f326633..7eb512b 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -40,6 +40,7 @@ static ssize_t regmap_name_read_file(struct file *file, loff_t *ppos) { struct regmap *map = file->private_data; + const char *name = "nodev"; int ret; char *buf; @@ -47,7 +48,10 @@ static ssize_t regmap_name_read_file(struct file *file, if (!buf) return -ENOMEM; - ret = snprintf(buf, PAGE_SIZE, "%s\n", map->dev->driver->name); + if (map->dev && map->dev->driver) + name = map->dev->driver->name; + + ret = snprintf(buf, PAGE_SIZE, "%s\n", name); if (ret < 0) { kfree(buf); return ret; -- 2.7.4