Re: [PATCH v2 1/4] landlock: Support file truncation

["Mickaël Salaün" <mic@digikod.net>]

On 12/07/2022 23:14, Günther Noack wrote:

[...]

> diff --git a/include/uapi/linux/landlock.h b/include/uapi/linux/landlock.h
> index 23df4e0e8ace..9ca7f9d0d862 100644
> --- a/include/uapi/linux/landlock.h
> +++ b/include/uapi/linux/landlock.h
> @@ -96,7 +96,12 @@ struct landlock_path_beneath_attr {
>    *
>    * - %LANDLOCK_ACCESS_FS_EXECUTE: Execute a file.
>    * - %LANDLOCK_ACCESS_FS_WRITE_FILE: Open a file with write access.
> + *   Note that you might additionally need the LANDLOCK_ACCESS_FS_TRUNCATE
> + *   right in order to overwrite files with open(2) using O_TRUNC or creat(2).

Please use the :manpage: notation for syscalls.


>    * - %LANDLOCK_ACCESS_FS_READ_FILE: Open a file with read access.
> + * - %LANDLOCK_ACCESS_FS_TRUNCATE: Truncate a file through file truncation
> + *   APIs like truncate(2), ftruncate(2), open(2) with O_TRUNC or creat(2).
> + *   This access right is available since the third version of the Landlock ABI.
>    *
>    * A directory can receive access rights related to files or directories.  The
>    * following access right is applied to the directory itself, and the
> @@ -139,10 +144,9 @@ struct landlock_path_beneath_attr {
>    *
>    *   It is currently not possible to restrict some file-related actions
>    *   accessible through these syscall families: :manpage:`chdir(2)`,
> - *   :manpage:`truncate(2)`, :manpage:`stat(2)`, :manpage:`flock(2)`,
> - *   :manpage:`chmod(2)`, :manpage:`chown(2)`, :manpage:`setxattr(2)`,
> - *   :manpage:`utime(2)`, :manpage:`ioctl(2)`, :manpage:`fcntl(2)`,
> - *   :manpage:`access(2)`.
> + *   :manpage:`stat(2)`, :manpage:`flock(2)`, :manpage:`chmod(2)`,
> + *   :manpage:`chown(2)`, :manpage:`setxattr(2)`, :manpage:`utime(2)`,
> + *   :manpage:`ioctl(2)`, :manpage:`fcntl(2)`, :manpage:`access(2)`.
>    *   Future Landlock evolutions will enable to restrict them.
>    */
>   /* clang-format off */