From 6db6652abc3d81e155b6c8740065e9a4927825d9 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Mon, 12 Oct 2015 18:09:11 -0700 Subject: [PATCH] debugfs: Add read-only/write-only size_t file ops There aren't any read-only or write-only size_t file ops, but there is a caller of debugfs_create_size_t() 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 | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index f69d42efe4b8..e8e73aebe6b8 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -352,6 +352,8 @@ static int debugfs_size_t_get(void *data, u64 *val) } DEFINE_SIMPLE_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set, "%llu\n"); /* %llu and %zu are more or less the same */ +DEFINE_SIMPLE_ATTRIBUTE(fops_size_t_ro, debugfs_size_t_get, NULL, "%llu\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n"); /** * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value @@ -366,7 +368,8 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set, struct dentry *debugfs_create_size_t(const char *name, umode_t mode, struct dentry *parent, size_t *value) { - return debugfs_create_file(name, mode, parent, value, &fops_size_t); + return debugfs_create_mode(name, mode, parent, value, &fops_size_t, + &fops_size_t_ro, &fops_size_t_wo); } EXPORT_SYMBOL_GPL(debugfs_create_size_t);