From: Paul Moore <paul@paul-moore.com>
To: "Mickaël Salaün" <mic@digikod.net>
Cc: "James Morris" <jmorris@namei.org>,
"Serge E . Hallyn" <serge@hallyn.com>,
"Al Viro" <viro@zeniv.linux.org.uk>,
"Jann Horn" <jannh@google.com>,
"Kees Cook" <keescook@chromium.org>,
"Konstantin Meskhidze" <konstantin.meskhidze@huawei.com>,
"Shuah Khan" <shuah@kernel.org>,
linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
"Mickaël Salaün" <mic@linux.microsoft.com>
Subject: Re: [PATCH v1 02/11] landlock: Reduce the maximum number of layers to 16
Date: Wed, 16 Mar 2022 21:26:16 -0400 [thread overview]
Message-ID: <CAHC9VhSAc37rX1jFNpvRczkvbfdALYkP2xm3jPbAm8Eqnp9erw@mail.gmail.com> (raw)
In-Reply-To: <20220221212522.320243-3-mic@digikod.net>
On Mon, Feb 21, 2022 at 4:15 PM Mickaël Salaün <mic@digikod.net> wrote:
>
> From: Mickaël Salaün <mic@linux.microsoft.com>
>
> The maximum number of nested Landlock domains is currently 64. Because
> of the following fix and to help reduce the stack size, let's reduce it
> to 16. This seems large enough for a lot of use cases (e.g. sandboxed
> init service, spawning a sandboxed SSH service, in nested sandboxed
> containers). Reducing the number of nested domains may also help to
> discover misuse of Landlock (e.g. creating a domain per rule).
>
> Add and use a dedicated layer_mask_t typedef to fit with the number of
> layers. This might be useful when changing it and to keep it consistent
> with the maximum number of layers.
>
> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
> Link: https://lore.kernel.org/r/20220221212522.320243-3-mic@digikod.net
> ---
> security/landlock/fs.c | 13 +++++--------
> security/landlock/limits.h | 2 +-
> security/landlock/ruleset.h | 4 ++++
> tools/testing/selftests/landlock/fs_test.c | 2 +-
> 4 files changed, 11 insertions(+), 10 deletions(-)
I'm assuming that the drop in Landlock nesting down to 16 isn't going
to cause any userspace breakage :)
Reviewed-by: Paul Moore <paul@paul-moore.com>
--
paul-moore.com
next prev parent reply other threads:[~2022-03-17 1:27 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-21 21:25 [PATCH v1 00/11] Landlock: file linking and renaming support Mickaël Salaün
2022-02-21 21:25 ` [PATCH v1 01/11] landlock: Define access_mask_t to enforce a consistent access mask size Mickaël Salaün
2022-03-17 1:26 ` Paul Moore
2022-03-17 8:36 ` Mickaël Salaün
2022-03-17 21:31 ` Paul Moore
2022-02-21 21:25 ` [PATCH v1 02/11] landlock: Reduce the maximum number of layers to 16 Mickaël Salaün
2022-03-17 1:26 ` Paul Moore [this message]
2022-02-21 21:25 ` [PATCH v1 03/11] landlock: Create find_rule() from unmask_layers() Mickaël Salaün
2022-03-17 1:26 ` Paul Moore
2022-02-21 21:25 ` [PATCH v1 04/11] landlock: Fix same-layer rule unions Mickaël Salaün
2022-03-17 1:26 ` Paul Moore
2022-03-17 10:41 ` Mickaël Salaün
2022-03-17 21:34 ` Paul Moore
2022-02-21 21:25 ` [PATCH v1 05/11] landlock: Move filesystem helpers and add a new one Mickaël Salaün
2022-03-17 1:26 ` Paul Moore
2022-03-17 10:42 ` Mickaël Salaün
2022-02-21 21:25 ` [PATCH v1 06/11] landlock: Add support for file reparenting with LANDLOCK_ACCESS_FS_REFER Mickaël Salaün
2022-02-22 3:16 ` kernel test robot
2022-02-22 10:18 ` Mickaël Salaün
2022-03-17 1:26 ` Paul Moore
2022-03-17 12:04 ` Mickaël Salaün
2022-03-17 21:42 ` Paul Moore
2022-03-24 10:31 ` Mickaël Salaün
2022-02-21 21:25 ` [PATCH v1 07/11] selftest/landlock: Add 6 new test suites dedicated to file reparenting Mickaël Salaün
2022-02-21 21:25 ` [PATCH v1 08/11] samples/landlock: Add support for " Mickaël Salaün
2022-03-17 1:26 ` Paul Moore
2022-02-21 21:25 ` [PATCH v1 09/11] landlock: Document LANDLOCK_ACCESS_FS_REFER and ABI versioning Mickaël Salaün
2022-03-17 1:27 ` Paul Moore
2022-03-17 12:06 ` Mickaël Salaün
2022-02-21 21:25 ` [PATCH v1 10/11] landlock: Document good practices about filesystem policies Mickaël Salaün
2022-03-17 1:27 ` Paul Moore
2022-02-21 21:25 ` [PATCH v1 11/11] landlock: Add design choices documentation for filesystem access rights Mickaël Salaün
2022-03-17 1:27 ` Paul Moore
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