1 files changed, 35 insertions, 23 deletions

diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
index e5e1b3a01b1a..bfb357e273fb 100644
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -227,6 +227,9 @@ static ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from,
 	if (*ppos < 0 || !count)
 		return -EINVAL;
 
+	if (count > (PAGE_SIZE << (MAX_ORDER - 1)))
+		count = PAGE_SIZE << (MAX_ORDER - 1);
+
 	buf = kmalloc(count, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
@@ -371,6 +374,9 @@ static ssize_t regmap_reg_ranges_read_file(struct file *file,
 	if (*ppos < 0 || !count)
 		return -EINVAL;
 
+	if (count > (PAGE_SIZE << (MAX_ORDER - 1)))
+		count = PAGE_SIZE << (MAX_ORDER - 1);
+
 	buf = kmalloc(count, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
@@ -457,29 +463,31 @@ static ssize_t regmap_cache_only_write_file(struct file *file,
 {
 	struct regmap *map = container_of(file->private_data,
 					  struct regmap, cache_only);
-	ssize_t result;
-	bool was_enabled, require_sync = false;
+	bool new_val, require_sync = false;
 	int err;
 
-	map->lock(map->lock_arg);
+	err = kstrtobool_from_user(user_buf, count, &new_val);
+	/* Ignore malforned data like debugfs_write_file_bool() */
+	if (err)
+		return count;
 
-	was_enabled = map->cache_only;
+	err = debugfs_file_get(file->f_path.dentry);
+	if (err)
+		return err;
 
-	result = debugfs_write_file_bool(file, user_buf, count, ppos);
-	if (result < 0) {
-		map->unlock(map->lock_arg);
-		return result;
-	}
+	map->lock(map->lock_arg);
 
-	if (map->cache_only && !was_enabled) {
+	if (new_val && !map->cache_only) {
 		dev_warn(map->dev, "debugfs cache_only=Y forced\n");
 		add_taint(TAINT_USER, LOCKDEP_STILL_OK);
-	} else if (!map->cache_only && was_enabled) {
+	} else if (!new_val && map->cache_only) {
 		dev_warn(map->dev, "debugfs cache_only=N forced: syncing cache\n");
 		require_sync = true;
 	}
+	map->cache_only = new_val;
 
 	map->unlock(map->lock_arg);
+	debugfs_file_put(file->f_path.dentry);
 
 	if (require_sync) {
 		err = regcache_sync(map);
@@ -487,7 +495,7 @@ static ssize_t regmap_cache_only_write_file(struct file *file,
 			dev_err(map->dev, "Failed to sync cache %d\n", err);
 	}
 
-	return result;
+	return count;
 }
 
 static const struct file_operations regmap_cache_only_fops = {
@@ -502,28 +510,32 @@ static ssize_t regmap_cache_bypass_write_file(struct file *file,
 {
 	struct regmap *map = container_of(file->private_data,
 					  struct regmap, cache_bypass);
-	ssize_t result;
-	bool was_enabled;
+	bool new_val;
+	int err;
 
-	map->lock(map->lock_arg);
+	err = kstrtobool_from_user(user_buf, count, &new_val);
+	/* Ignore malforned data like debugfs_write_file_bool() */
+	if (err)
+		return count;
 
-	was_enabled = map->cache_bypass;
+	err = debugfs_file_get(file->f_path.dentry);
+	if (err)
+		return err;
 
-	result = debugfs_write_file_bool(file, user_buf, count, ppos);
-	if (result < 0)
-		goto out;
+	map->lock(map->lock_arg);
 
-	if (map->cache_bypass && !was_enabled) {
+	if (new_val && !map->cache_bypass) {
 		dev_warn(map->dev, "debugfs cache_bypass=Y forced\n");
 		add_taint(TAINT_USER, LOCKDEP_STILL_OK);
-	} else if (!map->cache_bypass && was_enabled) {
+	} else if (!new_val && map->cache_bypass) {
 		dev_warn(map->dev, "debugfs cache_bypass=N forced\n");
 	}
+	map->cache_bypass = new_val;
 
-out:
 	map->unlock(map->lock_arg);
+	debugfs_file_put(file->f_path.dentry);
 
-	return result;
+	return count;
 }
 
 static const struct file_operations regmap_cache_bypass_fops = {