From 6713e8fb541656d00249dca6627395b461c39ece Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Mon, 12 Oct 2015 18:09:12 -0700 Subject: [PATCH] debugfs: Add read-only/write-only bool file ops There aren't any read-only or write-only bool file ops, but there is a caller of debugfs_create_bool() that calls it with mode equal to 0400. This leads to the possibility of userspace modifying the file, so let's use the newly created debugfs_create_mode() helper here to fix this. Signed-off-by: Stephen Boyd Reviewed-by: Viresh Kumar Signed-off-by: Greg Kroah-Hartman --- fs/debugfs/file.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index e8e73aebe6b8..8450549d54a9 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -450,6 +450,18 @@ static const struct file_operations fops_bool = { .llseek = default_llseek, }; +static const struct file_operations fops_bool_ro = { + .read = debugfs_read_file_bool, + .open = simple_open, + .llseek = default_llseek, +}; + +static const struct file_operations fops_bool_wo = { + .write = debugfs_write_file_bool, + .open = simple_open, + .llseek = default_llseek, +}; + /** * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value * @name: a pointer to a string containing the name of the file to create. @@ -477,7 +489,8 @@ static const struct file_operations fops_bool = { struct dentry *debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent, bool *value) { - return debugfs_create_file(name, mode, parent, value, &fops_bool); + return debugfs_create_mode(name, mode, parent, value, &fops_bool, + &fops_bool_ro, &fops_bool_wo); } EXPORT_SYMBOL_GPL(debugfs_create_bool); -- 2.39.5