From: "Mickaël Salaün" <mic@digikod.net>
To: James Morris <jmorris@namei.org>, Jann Horn <jannh@google.com>,
"Serge E . Hallyn" <serge@hallyn.com>
Cc: "Mickaël Salaün" <mic@digikod.net>,
"Shuah Khan" <shuah@kernel.org>,
"Vincent Dagonneau" <vincent.dagonneau@ssi.gouv.fr>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org,
linux-security-module@vger.kernel.org
Subject: [PATCH v1 9/9] landlock: Extend documentation about limitations
Date: Wed, 11 Nov 2020 22:34:42 +0100 [thread overview]
Message-ID: <20201111213442.434639-10-mic@digikod.net> (raw)
In-Reply-To: <20201111213442.434639-1-mic@digikod.net>
Explain limitations for the maximum number of stacked ruleset, and the
memory usage restrictions.
Cc: James Morris <jmorris@namei.org>
Cc: Jann Horn <jannh@google.com>
Cc: Serge E. Hallyn <serge@hallyn.com>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
---
Documentation/userspace-api/landlock.rst | 17 +++++++++++++++++
security/landlock/syscall.c | 2 ++
2 files changed, 19 insertions(+)
diff --git a/Documentation/userspace-api/landlock.rst b/Documentation/userspace-api/landlock.rst
index 8f727de20479..7e83e5def1bc 100644
--- a/Documentation/userspace-api/landlock.rst
+++ b/Documentation/userspace-api/landlock.rst
@@ -186,6 +186,23 @@ Enforcing a ruleset
Current limitations
===================
+Ruleset layers
+--------------
+
+There is a limit of 64 layers of stacked rulesets. This can be an issue for a
+task willing to enforce a new ruleset in complement to its 64 inherited
+rulesets. Once this limit is reached, sys_landlock_enforce_ruleset_current()
+returns E2BIG. It is then strongly suggested to carefully build rulesets once
+in the life of a thread, especially for applications able to launch other
+applications which may also want to sandbox themselves (e.g. shells, container
+managers, etc.).
+
+Memory usage
+------------
+
+Kernel memory allocated to create rulesets is accounted and can be restricted
+by the :doc:`/admin-guide/cgroup-v1/memory`.
+
File renaming and linking
-------------------------
diff --git a/security/landlock/syscall.c b/security/landlock/syscall.c
index 543ae36cd339..045bcac79e17 100644
--- a/security/landlock/syscall.c
+++ b/security/landlock/syscall.c
@@ -361,6 +361,8 @@ SYSCALL_DEFINE4(landlock_add_rule,
* - EPERM: @ruleset_fd has no read access to the underlying ruleset, or the
* current thread is not running with no_new_privs, or it doesn't have
* CAP_SYS_ADMIN in its namespace.
+ * - E2BIG: The maximum number of stacked rulesets is reached for the current
+ * task.
*/
SYSCALL_DEFINE2(landlock_enforce_ruleset_current,
const int, ruleset_fd, const __u32, flags)
--
2.29.2
next prev parent reply other threads:[~2020-11-11 21:35 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-11 21:34 [PATCH v1 0/9] Landlock fixes Mickaël Salaün
2020-11-11 21:34 ` [PATCH v1 1/9] landlock: Fix memory allocation error handling Mickaël Salaün
2020-11-11 21:34 ` [PATCH v1 2/9] landlock: Cosmetic fixes for filesystem management Mickaël Salaün
2020-11-20 1:37 ` James Morris
2020-11-11 21:34 ` [PATCH v1 3/9] landlock: Enforce deterministic interleaved path rules Mickaël Salaün
2020-11-11 21:34 ` [PATCH v1 4/9] landlock: Always intersect access rights Mickaël Salaün
2020-11-11 21:34 ` [PATCH v1 5/9] landlock: Add extra checks when inserting a rule Mickaël Salaün
2020-11-11 21:34 ` [PATCH v1 6/9] selftests/landlock: Extend layout1.inherit_superset Mickaël Salaün
2020-11-11 21:34 ` [PATCH v1 7/9] landlock: Clean up get_ruleset_from_fd() Mickaël Salaün
2020-11-11 21:34 ` [PATCH v1 8/9] landlock: Add help to enable Landlock as a stacked LSM Mickaël Salaün
2020-11-11 21:34 ` Mickaël Salaün [this message]
2020-11-12 4:59 ` [PATCH v1 0/9] Landlock fixes James Morris
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201111213442.434639-10-mic@digikod.net \
--to=mic@digikod.net \
--cc=jannh@google.com \
--cc=jmorris@namei.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=serge@hallyn.com \
--cc=shuah@kernel.org \
--cc=vincent.dagonneau@ssi.gouv.fr \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).