* fix(sandbox): add parent-side Landlock availability probe logging
Landlock status was only logged from inside the pre_exec child process
where the tracing/OCSF pipeline is non-functional after fork. This made
Landlock failures completely invisible in sandbox logs.
Add a probe_availability() function that issues the raw
landlock_create_ruleset syscall to check kernel support, and call it
from the parent process before fork in all three spawn paths (entrypoint,
SSH PTY, SSH pipe). Uses std::sync::Once to emit exactly once per
sandbox lifetime.
WIP - addresses logging gap from #803.
* test(e2e): add Landlock filesystem enforcement tests
Verify Landlock availability logging and enforcement in e2e:
- OCSF probe event appears in sandbox logs
- Read-only paths block writes, allow reads
- Read-write paths allow both
- Paths outside policy are denied entirely
- User-owned paths outside policy are still blocked (proves
Landlock enforces independently of Unix DAC permissions)
Requires Linux host with Landlock support (GitHub Actions runners,
Docker Desktop linuxkit). Related to #803.
* test(e2e): add xfail tests proving #803 privilege ordering bug
Two strict xfail tests that demonstrate the root cause of #803:
- PathFd::new() runs as uid 998 after drop_privileges, so root-only
paths (mode 700) silently fail and Landlock degrades
- When ALL paths fail, best_effort silently drops Landlock entirely
These tests will pass after the two-phase Landlock fix (open PathFds
as root before drop_privileges, restrict_self after).
* fix(test): fix Landlock e2e tests based on test run results
- Remove log-reading tests: the Landlock probe logs to the
supervisor's container stdout, not the in-sandbox file appender
at /var/log/openshell*.log*
- Replace broken xfail test (checked for child-process log messages
that never reach the file appender) with a stat()-based test that
verifies /root is actually in the Landlock allowlist
- Keep enforcement tests (all passing) and the root-only policy
xfail test (correctly proves #803 bug)
* fix(test): remove mixed-policy xfail test
Landlock doesn't restrict stat(), so the test passed unexpectedly.
In the mixed policy case where /root is silently skipped, Landlock
still applies (using other paths) and blocks /root even harder
(not in allowlist = denied). The observable security degradation
only occurs when ALL paths fail, which the existing xfail test
already covers.
* fix(sandbox): two-phase Landlock to fix privilege ordering (#803)
Split Landlock apply into prepare() and enforce():
- prepare() runs as root before drop_privileges: opens PathFds,
creates ruleset, adds rules. Root-only paths (mode 700) now
succeed instead of silently failing as uid 998.
- enforce() runs after drop_privileges: calls restrict_self()
which does not require root.
This fixes the root cause of #803 where drop_privileges() ran
before sandbox::apply(), causing PathFd::new() to fail on
root-only paths. In best_effort mode this silently dropped all
Landlock restrictions.
The fix applies to all three spawn paths: entrypoint (process.rs),
SSH PTY (ssh.rs), and SSH pipe exec (ssh.rs).
Removes xfail marker from e2e test that now passes.
* fix(sandbox): address PR review feedback
- enforce() now respects best_effort: if restrict_self() fails and
policy is best_effort, log and degrade instead of aborting startup
- log_sandbox_readiness distinguishes best_effort (degraded) from
hard_requirement (will fail) in OCSF messages
