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| author | Mickaël Salaün <mic@digikod.net> | 2022-05-06 18:10:52 +0200 |
|---|---|---|
| committer | Mickaël Salaün <mic@digikod.net> | 2022-05-23 13:27:56 +0200 |
| commit | 75c542d6c6cc48720376862d5496d51509160dfd (patch) | |
| tree | f7411e602afa044becdad12369614e004c439fd1 /Documentation/userspace-api | |
| parent | landlock: Define access_mask_t to enforce a consistent access mask size (diff) | |
| download | linux-75c542d6c6cc48720376862d5496d51509160dfd.tar.xz linux-75c542d6c6cc48720376862d5496d51509160dfd.zip | |
landlock: Reduce the maximum number of layers to 16
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.
Reviewed-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20220506161102.525323-3-mic@digikod.net
Cc: stable@vger.kernel.org
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Diffstat (limited to 'Documentation/userspace-api')
| -rw-r--r-- | Documentation/userspace-api/landlock.rst | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/Documentation/userspace-api/landlock.rst b/Documentation/userspace-api/landlock.rst index f35552ff19ba..b68e7a51009f 100644 --- a/Documentation/userspace-api/landlock.rst +++ b/Documentation/userspace-api/landlock.rst @@ -267,8 +267,8 @@ restrict such paths with dedicated ruleset flags. 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 +There is a limit of 16 layers of stacked rulesets. This can be an issue for a +task willing to enforce a new ruleset in complement to its 16 inherited rulesets. Once this limit is reached, sys_landlock_restrict_self() 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 |