Filesystem denial traces identify the policy change needed to allow a
request, so require exact blocker values rather than merely nonempty
output. Pin a READ_DIR denial to exactly one event with
blockers=read_dir. Pin a REFER-only mount denial to EPERM and exactly
one event with blockers=change_topology.
The mount child retains CAP_SYS_ADMIN so Landlock is the only expected
source of EPERM. This prevents a later capability failure from masking
a Landlock regression; the trace-collecting parent remains unsandboxed.
Cc: Günther Noack <gnoack@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: https://patch.msgid.link/20260918185036.608651-8-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Name each event after the identity it reports. Add-rule events describe
UAPI rule insertion, so rename them after LANDLOCK_RULE_PATH_BENEATH and
LANDLOCK_RULE_NET_PORT. Check-rule events describe matches in internal
rule trees, so rename them after LANDLOCK_KEY_INODE and
LANDLOCK_KEY_NET_PORT. This remains accurate if multiple UAPI rule types
share one lookup and stored rule. Keep denial event names based on
filesystem and network families because they describe final access
decisions.
Use u64 for growable access masks passed by value to add-rule and
check-rule typed BTF callbacks. CO-RE can relocate pointer-reached
fields, but it cannot widen a scalar callback slot declared by a BPF
program. Keep native access_mask_t for internal state and trace records.
For add-rule callbacks, report the normalized per-call contribution
passed to landlock_insert_rule() and expose the complete validated flags
value. Put the ruleset and flags first as a common invocation prefix.
This distinguishes duplicate and effective-zero additions without
recovering arguments from saved syscall registers.
Cc: Günther Noack <gnoack@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Fixes: 63747c9477 ("landlock: Add landlock_add_rule_fs and landlock_add_rule_net tracepoints")
Fixes: 3f1f106e4c ("landlock: Add tracepoints for rule checking")
Link: https://patch.msgid.link/20260918185036.608651-4-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Use focused KUnit tests to exercise the renderer's internal boundary and
composition contracts with synthetic scratch states, including both
sibling-helper evaluation orders. Check the exact output and
reservation boundaries, including a four-byte octal escape accepted at
exact capacity and rejected one byte short. Also verify an unchanged
cursor on failure, that bracketed process names and embedded NUL bytes
remain data, and that input ellipsis bytes are escaped rather than
mistaken for the raw truncation marker.
The composition test requires generic trace output helpers. Enable
CONFIG_FTRACE and CONFIG_SCHED_TRACER because the latter selects the
otherwise-hidden CONFIG_TRACING support required by
trace_print_flags_seq().
Use kselftests to exercise the complete tracefs path for both affected
filesystem events. A valid path containing 2640 spaces exceeds the
scratch output budget. Require its escaped prefix to end in the raw
UTF-8 ellipsis while access_rights and blockers remain intact.
This division keeps the exact safety contract compiler-independent while
proving that real tracepoints preserve their surrounding symbolic
fields. The end-to-end assertions fail after a full fix revert with
both GCC and Clang, while the composition KUnit test fails if the
scratch reserve is removed.
Cc: Günther Noack <gnoack@google.com>
Link: https://patch.msgid.link/20260907154401.124362-2-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Add filesystem-specific trace tests in a dedicated file, following the
audit-test pattern of living alongside each subsystem's functional
tests.
trace_fs_test.c verifies that the add_rule_fs, check_rule_fs, and
deny_access_fs events fire with the correct fields on matching rules and
denied accesses, that check_rule_fs does not fire for unhandled access
types, and that no event fires without a sandbox. A denial covered by a
quiet rule still emits a deny_access_fs event but with logged=0, the
same suppression verdict audit applies; because that verdict must not
depend on CONFIG_AUDIT, the test also runs under a tracepoints-only
build.
Add trace_layout1 fixture tests in fs_test.c that reuse the layout1
hierarchy to verify the per-layer grants field: field values, multi-rule
pathwalk short-circuit, request intersection, the optional truncate
right surfacing in the request and grants, and an empty grants set from
a rule that grants none of the requested rights.
Cc: Günther Noack <gnoack@google.com>
Cc: Tingmao Wang <m@maowtm.org>
Link: https://patch.msgid.link/20260811094338.288094-16-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
