On Fri 13-09-24 13:00:14, Thorsten Blum wrote:
> Add the __counted_by compiler attribute to the flexible array member
> name to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
> CONFIG_FORTIFY_SOURCE.
>
> Inline and use struct_size() to calculate the number of bytes to
> allocate for new_fn and remove the local variable len.
>
> Signed-off-by: Thorsten Blum <thorsten.blum@xxxxxxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/ext4/dir.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
> index ff4514e4626b..8e7df15bb971 100644
> --- a/fs/ext4/dir.c
> +++ b/fs/ext4/dir.c
> @@ -408,7 +408,7 @@ struct fname {
> __u32 inode;
> __u8 name_len;
> __u8 file_type;
> - char name[];
> + char name[] __counted_by(name_len);
> };
>
> /*
> @@ -464,14 +464,13 @@ int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
> struct rb_node **p, *parent = NULL;
> struct fname *fname, *new_fn;
> struct dir_private_info *info;
> - int len;
>
> info = dir_file->private_data;
> p = &info->root.rb_node;
>
> /* Create and allocate the fname structure */
> - len = sizeof(struct fname) + ent_name->len + 1;
> - new_fn = kzalloc(len, GFP_KERNEL);
> + new_fn = kzalloc(struct_size(new_fn, name, ent_name->len + 1),
> + GFP_KERNEL);
> if (!new_fn)
> return -ENOMEM;
> new_fn->hash = hash;
> --
> 2.46.0
>
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
