summaryrefslogtreecommitdiff
path: root/tools/testing/selftests/landlock
AgeCommit message (Collapse)Author
22 hoursMerge branch 'next' of ↵Mark Brown
https://git.kernel.org/pub/scm/linux/kernel/git/mic/linux.git
24 hoursMerge branch 'next' of ↵Mark Brown
https://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm.git
2 daysselftests/landlock: Add capability restriction testsMickaël Salaün
Add tests to exercise LANDLOCK_PERMISSION_CAPABILITY_USE enforcement. A sandboxed process is denied a handled capability when no rule grants it, and an explicit rule restores it. Unknown capability values above CAP_LAST_CAP are accepted at rule-add time yet have no runtime effect, because deny-by-default still applies once the domain is enforced. Stacking tests cover the per-layer allow/deny combinations, including a layer that does not handle the permission, and invalid rule attributes return the expected errors. Three tests exercise non-standard capability contexts: enforcing a domain via CAP_SYS_ADMIN authorization without no_new_privs, restricting capabilities gained through the kernel's user namespace ownership bypass (cap_capable_helper), and checking CAP_SYS_ADMIN against a descendant user namespace, with an unsandboxed positive control, to confirm the decision is independent of the target. Audit tests verify denied and allowed capabilities, per-member quiet interactions, and CAP_OPT_NOAUDIT suppression. Trace tests cover accepted, rejected, and no-op rule adds, and normal, quiet, and CAP_OPT_NOAUDIT denials. Test coverage for security/landlock is 91.8% of 2864 lines according to LLVM 22. Cc: Christian Brauner <brauner@kernel.org> Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Serge E. Hallyn <serge@hallyn.com> Link: https://patch.msgid.link/20261014082718.1435842-7-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2 daysselftests/landlock: Add namespace restriction testsMickaël Salaün
Add tests covering LANDLOCK_PERMISSION_NAMESPACE_USE (namespace creation via unshare/clone and namespace entry via setns) and its interaction with LANDLOCK_PERMISSION_CAPABILITY_USE. Rule validation covers the forward-compatibility contract: unknown CLONE_NEW* bits, including holes, upper-range bits and bit 63, are accepted at rule-add time yet have no runtime effect, because deny-by-default still applies once the domain is enforced. Empty masks, invalid permission selectors and non-zero flags are rejected. Creation tests use FIXTURE_VARIANT to exercise all eight namespace types across allowed/denied and privileged/unprivileged combinations, so every type is shown to reach security_namespace_init(). Stacking tests cover the three per-layer allow/deny combinations that exercise distinct walker paths, and one domain handles both permissions at once. Entry tests subject setns to the same type-based check through security_namespace_install(), across processes, and require both permissions to allow a non-user namespace. The four open_tree(2) and fsmount(2) variants, anonymous and not, all create a mount namespace: they converge in security_namespace_init() with CLONE_NEWNS through different alloc_mnt_ns() paths. A CLONE_NEWUSER | CLONE_NEWUTS unshare under partial-allow rules shows that creation is sequential, so a denial on either type rolls the whole syscall back with EPERM. Audit tests cover allowed and denied creation and entry, per-member quiet masks and the youngest-denying-layer rule. Trace tests cover handled permissions, successful and rejected rules, version history, namespace IDs, and quiet denials, including repeated and unknown-only effective no-ops. Cc: Christian Brauner <brauner@kernel.org> Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Serge E. Hallyn <serge@hallyn.com> Link: https://patch.msgid.link/20261014082718.1435842-6-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2 dayslandlock: Enforce namespace use restrictionsMickaël Salaün
Add Landlock enforcement for namespace use through the LSM namespace_init and namespace_install hooks. This lets a sandboxed process restrict which namespace types it can create, join, or acquire a file descriptor for, using LANDLOCK_PERMISSION_NAMESPACE_USE and per-type rules. Introduce the handled_permissions field in struct landlock_ruleset_attr: each permission gates every use of a kernel-defined category (CLONE_NEW* namespace types, CAP_* capabilities) with complete deny-by-default coverage, so unknown member values need no validation, being denied until a rule allows them. This UAPI extension advances the Landlock ABI from 11 to 12. There is no domain-ancestry bypass and no namespace-creator tracking, only a flat per-layer allowed-types bitmask: hook_namespace_init() covers creation through clone(2), unshare(2), open_tree(2) and fsmount(2), and hook_namespace_install() covers setns(2). Each permission hook maps its member mask explicitly in the shared permission walker, which warns and denies if a future caller omits that mapping. These categorical denials return -EPERM, matching Landlock's scope and mount-topology denials rather than its object-access -EACCES convention. struct permission_masks is forced to eight bytes with __packed and __aligned because it must eventually hold both the eight namespace types and all capabilities, and because m68k GCC otherwise packs its u64 bitfields at byte granularity, making the structure smaller than sizeof(u64). Carrying it grows struct layer_config from 4 to 16 bytes, so the largest 16-entry domain FAM grows from 64 to 256 bytes. The permissions selector keeps the rule attribute self-describing: - User space can mask it against handled_permissions, as it masks allowed_access against handled_access_fs, so a program built against newer headers still adds the rules an older kernel supports. - It tells apart two attributes that share the same three-u64 layout. Unknown member bits are ignored, so without it a mismatched rule type would apply a capability mask as namespace types. - It leaves room for a rule to carry several permissions, or for another rule type to key the same permission differently. The rule also carries a quiet_namespace_types bitmask that suppresses audit submission for denied members without granting them. A sandbox knowingly running a caller that probes a type it will never be granted would otherwise flood the audit log and drown the surprising denials that matter. Quiet is per-member rather than a coarse per-category ruleset bit, so a sandbox can silence CLONE_NEWNET while still auditing CLONE_NEWUTS; making it the complement of the allowed set would be broad, could not audit a member that is neither allowed nor explicitly quieted, and would auto-hide members added by future kernels. It is a per-rule bitmask rather than the LANDLOCK_ADD_RULE_QUIET flag and the ruleset quiet_access_* masks, which suit the unbounded rb-tree objects of filesystem and network rules, so that flag is rejected here. Only the youngest denying layer's quiet mask decides, so a parent cannot silence a denial made by a deeper layer. Trace the handled permission mask, every successful namespace rule, and namespace denials. Successful effective no-ops advance the version, and quiet denials remain trace-visible with logged=0. The denial event takes the blockers argument of the filesystem and network events and records the same blockers_type and blockers_access fields, so one filter expression spans the mask-bearing denial events. Handled and rule permission masks may contain permissions from multiple domains in one field, so their names are domain-qualified, such as namespace.use. A blocker is already interpreted in the domain supplied by the audit prefix or denial event, so it retains the bare action name use, matching existing access blockers such as read_file. User namespace creation does not require capabilities, so Landlock can restrict it directly. Non-user namespace types require CAP_SYS_ADMIN before the Landlock check is reached; when the capability permission added by the next commit is also handled, both must allow the operation. Cc: Christian Brauner <brauner@kernel.org> Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Serge E. Hallyn <serge@hallyn.com> Link: https://patch.msgid.link/20261014082718.1435842-4-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-09-20selftests/landlock: Test network denial contextMickaël Salaün
Network denial events now report the port from their one authoritative validated address through one signed field. Verify this value directly without inferring a source or destination role. Exercise a nonzero IPv4 TCP bind, an explicit-zero IPv4 UDP bind, a synthetic-zero IPv6 UDP autobind, and a family-only AF_UNSPEC UDP send. Require exactly one event with the exact policy blocker for each shape. The value -1 distinguishes a family-only address with no validated port from the two valid port-zero cases. Test coverage for security/landlock is 91.6% of 2625 lines according to LLVM 22. Cc: Günther Noack <gnoack@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: https://patch.msgid.link/20260918185036.608651-9-mic@digikod.net [mic: Add test coverage] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-09-20selftests/landlock: Test filesystem denial blockersMickaël Salaün
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>
2026-09-20landlock: Fix network denial trace contextMickaël Salaün
Network denial events report source and destination ports reconstructed from audit data. Their zero values are ambiguous, and neither identifies the complete endpoint that Landlock checked. Carry the checked sockaddr and its signed length in a private trace-only context. For an enabled event, validate the length and copy only the initialized prefix into zeroed local storage. This prevents a typed BPF program from reading uninitialized bytes while exposing the socket family, socket, address, and length. Replace the source and destination trace-record fields with one signed port derived from the checked address. A value of -1 means that no port was checked, zero is a valid port, and positive values use host endianness. Bind blockers select the bind address; connect and send blockers select the destination. Cc: Günther Noack <gnoack@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Fixes: 01ce260f5ccf ("landlock: Add landlock_deny_access_fs and landlock_deny_access_net") Link: https://patch.msgid.link/20260918185036.608651-5-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-09-20landlock: Fix rule tracepoint contextMickaël Salaün
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: 63747c94774d ("landlock: Add landlock_add_rule_fs and landlock_add_rule_net tracepoints") Fixes: 3f1f106e4c14 ("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>
2026-09-14selftests/landlock: Check full ioctl commands in audit recordsMickaël Salaün
The ioctl audit test uses FIONREAD, whose command value fits in 16 bits. It therefore cannot detect truncation of encoded direction and size bits. Use an architecture-independent unknown command with set upper bits and require its complete value in the audit record. Landlock rejects the command before the device handles it, and the existing ioctl enforcement test already exercises the same request. The new expectation fails with ioctlcmd=0xfeee on an unfixed kernel and passes with ioctlcmd=0xc00ffeee after the shared audit field is widened. Signed-off-by: Mickaël Salaün <mic@digikod.net> Reviewed-by: Günther Noack <gnoack@google.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2026-09-08landlock: Test trace path output boundariesMickaël Salaün
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>
2026-09-07selftests/landlock: Test abstract socket trace name limitsMickaël Salaün
The landlock_deny_scope_abstract_unix_socket event captures binary socket names with __string_len(), whose dynamic field reserves an extra byte for the NUL terminator. The printer subtracts this byte before escaping the content. Exercise the minimum accepted address length, which has no name content, and the maximum sockaddr_un length, which has 107 content bytes. Check the exact trace output at both boundaries. The existing stream and datagram variants share this event, so the boundary variants only need the stream path. Because these boundary names are fixed, run the fixture in a private network namespace. Abstract UNIX socket names are scoped by network namespace, preventing concurrent bind() calls from colliding. The lower-bound test confirms that the subtraction recovers zero instead of underflowing. Cc: Günther Noack <gnoack@google.com> Link: https://patch.msgid.link/CAL4aGcVcT0VWVFmGi_vLqxxZ9KdOHfGXYZtKjBdvoUyFjbu5=A@mail.gmail.com Link: https://patch.msgid.link/20260907103503.109461-1-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-17selftests/landlock: Add landlock_enforce_domain trace testsMickaël Salaün
Add trace tests for the landlock_enforce_domain event in trace_test.c, asserting field counts after the syscall returns rather than line ordering across per-CPU buffers. They cover single-threaded and TSYNC enforcement (complete and process_wide set), a multi-threaded non-TSYNC process (process_wide clear), the single-threaded non-leader edge case, the flags-only path that creates no domain, and a thread-sync abort that emits create_domain and free_domain but no enforce_domain. landlock_enforce_domain is added to the fixture enable path and every disable list so its zero-events assertions cannot be tripped by a stray enforcement event. Test coverage for security/landlock is 91.6% of 2571 lines according to LLVM 22. Cc: Günther Noack <gnoack@google.com> Cc: Tingmao Wang <m@maowtm.org> Link: https://patch.msgid.link/20260811094338.288094-19-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-17selftests/landlock: Add scope and ptrace tracepoint testsMickaël Salaün
Add trace tests for the landlock_deny_ptrace, landlock_deny_scope_signal, and landlock_deny_scope_abstract_unix_socket tracepoints, each placed alongside the functional tests for its subsystem, mirroring the audit test layout. Each tracepoint is exercised by a fixture with three variants that pin both branches of the other-party domain field: denied against an unsandboxed other party (other-party domain ID 0), denied against a sandboxed other party (non-zero ID), and an allowed baseline that records no event. A second fixture per type exercises an alternate LSM hook that reaches the same tracepoint with the same other-party domain ID, since each denial type can be reached through more than one hook. The datagram abstract-unix variant does not assert peer_pid, which is 0 for a datagram peer (no SO_PEERCRED); sun_path is the reliable peer identifier. The ptrace fixtures install a plain domain-creating ruleset rather than a dedicated flag, since ptrace denial relies on domain ancestry, not on a specific scoped flag. The fixtures unshare the mount namespace and remount / as MS_PRIVATE before mounting tracefs so the helper instance is visible only to the test process. Cc: Günther Noack <gnoack@google.com> Cc: Tingmao Wang <m@maowtm.org> Link: https://patch.msgid.link/20260811094338.288094-18-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-17selftests/landlock: Add network tracepoint testsMickaël Salaün
Add network-specific trace tests, co-located with the existing audit fixture so each subsystem's functional, audit, and trace tests live together. Parameterized fixtures verify the landlock_deny_access_net event: a bind or connect denied outside the ruleset emits exactly one event with the expected sport/dport, an allowed bind or connect emits none, and the unsandboxed baseline emits none. A separate fixture verifies the landlock_check_rule_net event on an allowed bind, anchoring its domain, access_request, port, and grants to exact values; only check_rule_fs had a dedicated field test before. Port fields are read in host endianness, matching the landlock_net_port_attr.port UAPI convention, so the decimal comparisons also catch byte-order regressions in the tracepoint plumbing. IPv6 trace tests are intentionally elided: IPv6 hook dispatch shares the current_check_access_socket() path with IPv4 (covered by the audit tests), and the trace fields do not depend on address family. Cc: Günther Noack <gnoack@google.com> Cc: Tingmao Wang <m@maowtm.org> Link: https://patch.msgid.link/20260811094338.288094-17-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-17selftests/landlock: Add filesystem tracepoint testsMickaël Salaün
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>
2026-08-17selftests/landlock: Add trace event test infrastructure and testsMickaël Salaün
Add tracefs test infrastructure in trace.h: helpers for mounting tracefs, enabling/disabling events, reading the trace buffer, counting regex matches, and extracting field values, plus per-event regex patterns. The patterns are anchored with ^ and $, verify every TP_printk field, and use no unescaped dot characters; TRACE_PREFIX matches the ftrace line format with either the expected task name (truncated to TASK_COMM_LEN - 1) or "<...>" for an evicted comm cache entry. Add trace_test.c with the trace fixture (setup enables all available events with a PID filter, teardown disables and clears) and the lifecycle, API, denial-field, and log-flag tests. Extend the existing true helper to open its working directory before exiting, triggering a read_dir denial inside a sandbox, so the exec-based tests can verify same_exec and the logged decision across an exec. Move regex_escape() from audit.h to common.h for shared use by the audit and trace tests. Enable CONFIG_ENABLE_DEFAULT_TRACERS alongside CONFIG_FTRACE in the selftest config: CONFIG_FTRACE alone only enables the tracer menu without activating any tracer, while CONFIG_ENABLE_DEFAULT_TRACERS selects TRACING (and thus TRACEPOINTS and event tracing) without depending on architecture-specific syscall tracepoints. When CONFIG_FTRACE is disabled it cannot be set, so TRACEPOINTS is correctly disabled too. Cc: Günther Noack <gnoack@google.com> Cc: Tingmao Wang <m@maowtm.org> Link: https://patch.msgid.link/20260811094338.288094-15-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-15selftests/landlock: Test LANDLOCK_RESTRICT_SELF_NO_NEW_PRIVSJustin Suess
Check that a successful landlock_restrict_self(2) call with LANDLOCK_RESTRICT_SELF_NO_NEW_PRIVS sets no_new_privs without a prior prctl(2) call nor CAP_SYS_ADMIN, that a failed call from both an invalid ruleset and hitting the layer maximum leaves the attribute unchanged, and that LANDLOCK_RESTRICT_SELF_TSYNC extends it to sibling threads. Also check that this flag requires a ruleset. Turn the multi_threaded_success test into a multi_threaded fixture with success, no_new_privs, and no_new_privs_max_layers variants to factor out the threading code. Finally, rename restrict_self_fd_logging_flags to restrict_self_fd_flags, and restrict_self_logging_flags to restrict_self_flags to indicate that non-logging flags are now tested. Test coverage for security/landlock is 91.8% of 2373 lines according to LLVM 22. Signed-off-by: Justin Suess <utilityemal77@gmail.com> Link: https://patch.msgid.link/20260809154544.1253100-4-utilityemal77@gmail.com Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-15landlock: Add LANDLOCK_RESTRICT_SELF_NO_NEW_PRIVSJustin Suess
Add a landlock_restrict_self(2) flag to set the no_new_privs attribute of the calling thread only after enforcement of the ruleset: no_new_privs is set if and only if the call succeeds. This removes the need for a prior prctl(2) PR_SET_NO_NEW_PRIVS call and guarantees that a failed enforcement leaves the attribute unchanged. Because no_new_privs is set by the call itself, the no_new_privs / CAP_SYS_ADMIN requirement of landlock_restrict_self(2) is fulfilled by construction, and the related EPERM check is skipped. Unlike LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF, this flag always requires a valid ruleset: with a ruleset_fd of -1, such a call would be nothing more than a Landlock-flavored prctl(2) PR_SET_NO_NEW_PRIVS, and there is no valid use case for setting no_new_privs (possibly with LANDLOCK_RESTRICT_SELF_TSYNC) without also enforcing Landlock restrictions. Rejecting these calls also keeps the option of giving them a meaning later. The attribute is only set past the last point of failure, just before committing the new credentials. When combined with LANDLOCK_RESTRICT_SELF_TSYNC, no_new_privs is set on the sibling threads as well, in their commit phase, with the same ordering. Bump the Landlock ABI version to 11, and include the minimal related test changes to keep the tests bisectable. Cc: Mickaël Salaün <mic@digikod.net> Signed-off-by: Justin Suess <utilityemal77@gmail.com> Link: https://patch.msgid.link/20260809212459.2427878-1-utilityemal77@gmail.com Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-15landlock: Check landlock_restrict_self(2)'s flags before privilegesJustin Suess
landlock_restrict_self(2) currently checks the no_new_privs / CAP_SYS_ADMIN requirement before validating the flags argument. An unprivileged caller without no_new_privs thus gets EPERM even when the passed flags are invalid, hiding the EINVAL error. Move the no_new_privs / CAP_SYS_ADMIN check just after the flags check so that malformed calls consistently error out with EINVAL whatever the caller's privileges, the same way seccomp(2) validates its flags before checking no_new_privs. Update the restrict_self_checks_ordering test accordingly. Cc: Mickaël Salaün <mic@digikod.net> Signed-off-by: Justin Suess <utilityemal77@gmail.com> Link: https://patch.msgid.link/20260809154544.1253100-2-utilityemal77@gmail.com Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-15selftests/landlock: Test whiteout object behaviour in OverlayFS renamesGünther Noack
Even though OverlayFS uses vfs_rename() with RENAME_WHITEOUT on its backing directories, and even though RENAME_WHITEOUT requires LANDLOCK_ACCESS_FS_MAKE_REG, a process that renames non-regular files in an OverlayFS can do so without having the LANDLOCK_ACCESS_FS_MAKE_REG right in that location. This works, and is supposed to work, because the changes to the backing directories are done by OverlayFS, not by the originator task that did the original rename() on the OverlayFS mount. Therefore, the changes done to backing directories are not subject to the originator task's credentials. Test coverage for security/landlock is 91.8% of 2368 lines according to LLVM 22. Signed-off-by: Günther Noack <gnoack@google.com> Link: https://patch.msgid.link/20260813093157.1436894-6-gnoack@google.com [mic: Add test coverage, reflow commit message] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-15selftests/landlock: Add audit test for whiteout object creationGünther Noack
Add audit_layout1.make_whiteout: This test looks similar to audit_layout1.make_char, but creates a whiteout object through mknod(). Since whiteout object creation is now guarded with LANDLOCK_ACCESS_FS_MAKE_REG rather than LANDLOCK_ACCESS_FS_MAKE_CHAR, it also needs to log the matching denial to audit. Signed-off-by: Günther Noack <gnoack@google.com> Link: https://patch.msgid.link/20260813093157.1436894-5-gnoack@google.com Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-15selftests/landlock: Add tests for whiteout object creationGünther Noack
Add tests to check that whiteout object creation is guarded by LANDLOCK_ACCESS_FS_MAKE_REG, in the cases where these are created from userspace: * Conventional creation with mknod() * Linking or renaming an existing whiteout object * renameat2() with RENAME_WHITEOUT, which creates a new whiteout object in the source location * renameat2() with RENAME_EXCHANGE, with one of the renamed objects being a whiteout object Signed-off-by: Günther Noack <gnoack@google.com> Link: https://patch.msgid.link/20260813093157.1436894-4-gnoack@google.com [mic: Update commit message as requested] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-15selftests/landlock: Use an actual chardev for MAKE_CHAR audit testGünther Noack
By passing a (0, 0) device number, the audit test for LANDLOCK_ACCESS_FS_MAKE_CHAR was accidentally creating a whiteout object rather than a char device. In preparation to treating whiteout objects differently, use an actual character device instead. Signed-off-by: Günther Noack <gnoack@google.com> Link: https://patch.msgid.link/20260813093157.1436894-2-gnoack@google.com Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-14selftests/landlock: Fix spelling error in fs_test commentWang Yan
Fix typo "allowes" -> "allows" in Landlock filesystem test comment. Signed-off-by: Wang Yan <wangyan01@kylinos.cn> Reviewed-by: Günther Noack <gnoack@google.com> Link: https://patch.msgid.link/20260702015823.368529-1-wangyan01@kylinos.cn Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-07-10selftests/landlock: Skip scoped_signal subtest with MSG_OOB if not availableThomas Huth
MSG_OOB might be disabled in the kernel for unix sockets (by not selecting CONFIG_AF_UNIX_OOB), and in this case the related tests of the scoped_signal_test are currently failing. Add a runtime probe using socketpair() to detect MSG_OOB support and skip the test gracefully if it is unavailable. Signed-off-by: Thomas Huth <thuth@redhat.com> Link: https://patch.msgid.link/20260710081642.405916-1-thuth@redhat.com Cc: stable@vger.kernel.org Fixes: f34e9ce5f479 ("selftests/landlock: Test signal created by out-of-bound message") Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-07-10selftests/landlock: Fix screwed up pointers in the scoped_signal_testThomas Huth
The scoped_signal_test uses pthread_join(..., (void **)&ret)) in a couple of places, i.e. the return value of the thread is stored in the shape of a "void *" into the memory location of &ret. Pointers are 64-bit on modern computers, but the ret variable is declared as a simple "enum thread_return" which is only 32 bits. So the pthread_join() will overflow the ret variable by 4 byte. The problem is very visible on big endian systems like s390x where the test is failing: The least significant byte that carries the return code of the thread is not written into the ret variable here, but somewhere else in the stack frame, so the comparison for the right return code is failing here. Fix it by getting rid of the enum and defining the THREAD_* constants and "ret" variables as proper "void *" pointers. This way we can also get rid of some ugly (void *) castings in a couple of spots. Signed-off-by: Thomas Huth <thuth@redhat.com> Link: https://patch.msgid.link/20260709164340.339656-1-thuth@redhat.com Cc: stable@vger.kernel.org Fixes: c8994965013e ("selftests/landlock: Test signal scoping for threads") [mic: Add clang-format markups] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-07-10selftests/landlock: Add test for TCP fast openMatthieu Buffet
Enforce that TCP Fast Open is controlled by LANDLOCK_ACCESS_NET_CONNECT_TCP. Semantics of connect() and sendmsg(MSG_FASTOPEN) should be identical from Landlock's perspective. Also enforce error code consistency, since UDP sockets ignore the MSG_FASTOPEN flag while Unix sockets reject it. Signed-off-by: Matthieu Buffet <matthieu@buffet.re> Link: https://patch.msgid.link/20260701214628.33319-2-matthieu@buffet.re Cc: stable@vger.kernel.org [mic: Fix formatting] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-06-14selftests/landlock: Add tests for invalid use of quiet flagTingmao Wang
Make sure that these calls return EINVAL. Test coverage for security/landlock is 91.6% of 2347 lines according to LLVM 22. Assisted-by: GitHub-Copilot:claude-opus-4.8 Signed-off-by: Tingmao Wang <m@maowtm.org> Link: https://patch.msgid.link/9401d5c6468675863d944d6c26640d97db1a1f31.1781228815.git.m@maowtm.org [mic: Add test coverage] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-06-14selftests/landlock: Add tests for quiet flag with scopeTingmao Wang
Enhance scoped_audit.connect_to_child and audit_flags.signal to test interaction with various quiet flag settings. Signed-off-by: Tingmao Wang <m@maowtm.org> Link: https://patch.msgid.link/032849ca97bd45b2e14f96192b61537ed9405a0d.1781228815.git.m@maowtm.org [mic: Fix comment formatting] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-06-14selftests/landlock: Add tests for quiet flag with net rulesTingmao Wang
Tests that: - Quiet flag works on network rules - Quiet flag applied to unrelated ports has no effect - Denied access not in quiet_access_net is still logged This is not as thorough as the fs tests, but given the shared logic it should be sufficient. There is also no "optional" access for network rules. Signed-off-by: Tingmao Wang <m@maowtm.org> Assisted-by: GitHub-Copilot:claude-opus-4.7 copilot-review Link: https://patch.msgid.link/364fbd08081318d64bc23049d3a7721f0a3a3624.1781228815.git.m@maowtm.org Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-06-14selftests/landlock: Add tests for quiet flag with fs rulesTingmao Wang
Test various interactions of the quiet flag with filesystem rules: - Non-optional access (tested with open and rename). - Optional access (tested with truncate and ioctl). - Behaviour around mounts matches with normal Landlock rules. - Behaviour around disconnected directories matches with normal Landlock rules (test expected behaviour of 9a868cdbe66a ("landlock: Fix handling of disconnected directories") applied to the collected quiet flag). - Multiple layers works as expected. Assisted-by: GitHub-Copilot:claude-opus-4.6 copilot-review Signed-off-by: Tingmao Wang <m@maowtm.org> Link: https://patch.msgid.link/0f304507dd3ebccc753e1580456bdfc909012357.1781228815.git.m@maowtm.org [mic: Fix comment formatting] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-06-14selftests/landlock: Replace hard-coded 16 with a constantTingmao Wang
The next commit will reuse this number. Make it a shared constant to future-proof changes. Signed-off-by: Tingmao Wang <m@maowtm.org> Link: https://patch.msgid.link/eff35caa9b4ac51aa83a88d67c4dd67f4f8b3a4a.1781228815.git.m@maowtm.org Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-06-14landlock: Add API support and docs for the quiet flagsTingmao Wang
Adds the UAPI for the quiet flags feature (but not the implementation yet). Even though currently LANDLOCK_ADD_RULE_QUIET only affects audit logging, in the future this can also be used as part of a supervisor mechanism, where it will also suppress denial notifications on a per-object basis. Thus the name is deliberately generic, as opposed to e.g. LANDLOCK_ADD_RULE_LOG_QUIET. According to pahole, even after adding the struct access_masks quiet_masks in struct landlock_hierarchy, the u32 log_* bitfield still only has a size of 2 bytes, so there's minimal wasted space. Assisted-by: GitHub-Copilot:claude-opus-4.8 Signed-off-by: Tingmao Wang <m@maowtm.org> [mic: Update date, fix comment formatting] Link: https://patch.msgid.link/031184748a8e74c0bb02f1fa13d7a3f10918c627.1781228815.git.m@maowtm.org Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-06-13selftests/landlock: Add tests for UDP sendMatthieu Buffet
Add tests specific to UDP sendmsg() in the protocol_* variants to ensure behaviour is consistent across AF_INET, AF_INET6 and AF_UNIX. Signed-off-by: Matthieu Buffet <matthieu@buffet.re> Link: https://patch.msgid.link/20260611162107.49278-5-matthieu@buffet.re [mic: Fix comment formatting, rebase] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-06-13selftests/landlock: Add tests for UDP bind/connectMatthieu Buffet
Make basic changes to the existing bind() and connect() test suite to cover UDP restriction. Signed-off-by: Matthieu Buffet <matthieu@buffet.re> Link: https://patch.msgid.link/20260611162107.49278-4-matthieu@buffet.re [mic: Update audit.connect_bound, fix comment formatting] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-06-13landlock: Add UDP send+connect access controlMatthieu Buffet
Add support for a second fine-grained UDP access right. LANDLOCK_ACCESS_NET_CONNECT_SEND_UDP controls the ability to set the remote port of a socket (via connect()) and to specify an explicit destination when sending a datagram, to override any remote peer set on a UDP socket (e.g. in sendto() or sendmsg()). It will be useful for applications that send datagrams, and for some servers too (those creating per-client sockets, which want to receive traffic only from a specific address). Similarly as for bind(), this access control is performed when configuring sockets, not in hot code paths. Add detection of when autobind is about to be required, and deny the operation if the process would not be allowed to call bind(0) explicitly. Autobind can only be performed in udp_lib_get_port() from code paths already controlled by LSM hooks: when connect()ing, sending a first datagram, and in some splice() EOF edge case which, afaiu, can only happen after a remote peer has been set. This invariant needs to be preserved to keep bind policies actually enforced. Signed-off-by: Matthieu Buffet <matthieu@buffet.re> Link: https://patch.msgid.link/20260611162107.49278-3-matthieu@buffet.re [mic: Add quick return for non-sandboxed tasks, fix sa_family dereferencing, fix comment formatting] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-06-13landlock: Add UDP bind() access controlMatthieu Buffet
Add support for a first fine-grained UDP access right. LANDLOCK_ACCESS_NET_BIND_UDP controls the ability to set the local port of a UDP socket (via bind()). It will be useful for servers (to start receiving datagrams), and for some clients that need to use a specific source port (e.g. mDNS requires to use port 5353) For obvious performance concerns, access control is only enforced when configuring sockets, not when using them for common send/recv operations. Bump ABI to allow userspace to detect and use this new right. Signed-off-by: Matthieu Buffet <matthieu@buffet.re> Link: https://patch.msgid.link/20260611162107.49278-2-matthieu@buffet.re [mic: Fix comment formatting] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-06-13selftests/landlock: Explicitly disable audit in teardownsMaximilian Heyne
I'm seeing sporadic selftest failures, such as # RUN scoped_audit.connect_to_child ... # scoped_abstract_unix_test.c:314:connect_to_child:Expected 0 (0) == records.access (8) # connect_to_child: Test failed # FAIL scoped_audit.connect_to_child not ok 19 scoped_audit.connect_to_child This seems similar to what commit 3647a4977fb73d ("selftests/landlock: Drain stale audit records on init") tried to fix. However, the added drain loop is not effective. When setting the AUDIT_STATUS_PID, the kauditd_thread is woken up starting to send messages from the hold queue to the netlink. Depending on scheduling of this kthread not all messages might be send via the netlink in the 1 us interval. Therefore, instead of trying to drain the queue, let's just disable audit when running non-audit tests or more precisely disable it after audit-tests. This way we won't generate any new audit message that could interfere with the other tests. The comment saying that on process exit audit will be disabled is wrong. The closed file descriptor just causes an auditd_reset(), not a disablement. So future messages will be queued in the hold queue. Cc: stable@vger.kernel.org Fixes: 6a500b22971c ("selftests/landlock: Add tests for audit flags and domain IDs") Signed-off-by: Maximilian Heyne <mheyne@amazon.de> Link: https://patch.msgid.link/20260529-welsh-nagoya-b4d9ca60@mheyne-amazon [mic: Fix FD leak, update subject, call audit_cleanup() in audit_exec teardown] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-06-13selftests/landlock: Test SCOPE_SIGNAL on the SIGIO/fowner pgid pathBryam Vargas
Add regression tests for the LANDLOCK_SCOPE_SIGNAL handling of the asynchronous SIGIO delivery path (fcntl(F_SETOWN)) with a process-group owner. sigio_to_pgid_members covers the bypass: a sandboxed process at the head of its process group's PGID hlist (the default after fork()) arms F_SETOWN(-pgrp) + O_ASYNC and triggers the fan-out; the in-domain owner must be signaled (proving the trigger fired) while the non-sandboxed member of the group, outside the domain, must not. sigio_to_pgid_self covers the same-process guarantee: the owner is registered from a sandboxed non-leader thread, whose domain differs from the thread-group leader the kernel signals for a process-group owner. That leader belongs to the owner's own process and must still be signaled. Without the fix the first test sees the out-of-domain member signaled and the second sees the owner's own leader denied. Cc: stable@vger.kernel.org Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me> Reviewed-by: Günther Noack <gnoack3000@gmail.com> Link: https://patch.msgid.link/43370e89f7a896a583bf33d1cd171d02630e61bf.1780614610.git.hexlabsecurity@proton.me [mic: Fix comment] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-06-13landlock: Set audit_net.sk for socket access checksMickaël Salaün
Set audit_net.sk in current_check_access_socket() to provide the socket object to audit_log_lsm_data(). This makes Landlock consistent with AppArmor, which always sets .sk for socket operations, and with SELinux's generic socket permission checks. The socket's local and foreign address information (laddr, lport, faddr, fport) is logged by the shared lsm_audit.c infrastructure when the socket has bound or connected state. Fields with zero values are suppressed by print_ipv4_addr()/print_ipv6_addr(), so the audit output is unchanged for the common case of bind denials on unbound sockets. For connect denials after a prior bind, the bound local address (laddr, lport) appears before the existing sockaddr fields (daddr, dest). No existing fields are removed or reordered, and the new field names (laddr, lport, faddr, fport) are standard audit fields already emitted by other LSMs through the same lsm_audit.c code path. Add a connect_tcp_bound audit test that binds to an allowed port and then connects to a denied one, verifying that the denial record reports laddr/lport from the bound socket in addition to the connect destination. Cc: Günther Noack <gnoack@google.com> Cc: Tingmao Wang <m@maowtm.org> Cc: stable@vger.kernel.org Fixes: 9f74411a40ce ("landlock: Log TCP bind and connect denials") Link: https://patch.msgid.link/20260612172757.1003481-1-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-05-21selftests/landlock: Increase default audit socket timeoutMickaël Salaün
matches_log_fs() and other audit_match_record() callers intermittently return -EAGAIN under heavy debug configs (KASAN, lockdep). The audit record delivery pipeline is asynchronous: landlock_log_denial() queues the record to audit_queue, and kauditd_thread dequeues and delivers via netlink. Under debug configs, kauditd scheduling between audit_log_end() and netlink_unicast() can exceed a syscall round trip (more than 1 usec), which was the value of the socket timeout used for the recvfrom() calls. The observed failure [1] is an EAGAIN error code (-11) which means that the access record had not arrived within the 1 usec timeout of recvfrom(). The expected record does arrive, but only after matches_log_fs() has already returned. It is then consumed by a later audit_count_records() call, making records.access == 1 instead of 0. Switch the default socket timeout to the slow value (1 second) so all audit_match_record() callers wait long enough for kauditd delivery, and lower it to the fast value (1 usec) only on the two paths that expect no record: audit_count_records() and the expected_domain_id == 0 probe in matches_log_domain_deallocated(). audit_init() drains stale records with the fast timeout (terminating on -EAGAIN once the backlog is empty) and switches to the patient default before returning. 1 second gives ~10x margin over the observed maximum (~100 ms, while the happy path is ~23 us). Rename the timeval constants to reflect their new roles: - audit_tv_dom_drop (1 second) -> audit_tv_default: default socket timeout, patient enough for asynchronous kauditd delivery. - audit_tv_default (1 usec) -> audit_tv_fast: fast timeout for paths that expect no record (drain, audit_count_records(), probes). Invert the conditional in matches_log_domain_deallocated(). Check setsockopt returns on both the lower and restore paths; preserve the first error via !err when the restore fails after a prior error so the actionable return code is not masked by a bookkeeping failure. Cc: Günther Noack <gnoack@google.com> Cc: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Cc: stable@vger.kernel.org Depends-on: 07c2572a8757 ("selftests/landlock: Skip stale records in audit_match_record()") Fixes: 6a500b22971c ("selftests/landlock: Add tests for audit flags and domain IDs") Reported-by: Günther Noack <gnoack3000@gmail.com> Closes: https://lore.kernel.org/r/20260402.eb5c4e85f472@gnoack.org [1] Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202605111649.a8b30a62-lkp@intel.com Closes: https://lore.kernel.org/oe-lkp/202604300436.a07fae12-lkp@intel.com Tested-by: Günther Noack <gnoack3000@gmail.com> Link: https://patch.msgid.link/20260513105112.140137-2-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-05-21selftests/landlock: Filter dealloc records in audit_count_records()Mickaël Salaün
audit_count_records() counts both AUDIT_LANDLOCK_DOMAIN allocation and deallocation records in records.domain . Domain deallocation is tied to asynchronous credential freeing via kworker threads (landlock_put_ruleset_deferred), so the dealloc record can arrive after the drain in audit_init() and after the preceding audit_match_record() call. This causes flaky failures in tests that assert an exact records.domain count: a stale dealloc record from a previous test's domain inflates the count by one. Observed on x86_64 under build configurations that delay the kworker firing the dealloc callback (e.g. coverage instrumentation): the audit_layout1 tests in fs_test.c intermittently saw records.domain == 2 where 1 was expected. The fix is in the shared helper, so those existing checks become robust without needing a fs_test.c edit. Filter audit_count_records() with a regex to skip records containing deallocation status. The remaining domain records (allocation, emitted synchronously during landlock_log_denial()) are deterministic. Deallocation records are already tested explicitly via matches_log_domain_deallocated() in audit_test.c, which uses its own domain-ID-based filtering and longer timeout. With this filter in place, re-add the records.domain == 0 checks that were removed in commit 3647a4977fb7 ("selftests/landlock: Drain stale audit records on init") as a workaround for this race. Cc: Günther Noack <gnoack@google.com> Cc: stable@vger.kernel.org Depends-on: 07c2572a8757 ("selftests/landlock: Skip stale records in audit_match_record()") Fixes: 6a500b22971c ("selftests/landlock: Add tests for audit flags and domain IDs") Tested-by: Günther Noack <gnoack3000@gmail.com> Link: https://patch.msgid.link/20260513105112.140137-1-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07selftests/landlock: Simplify ruleset creation and enforcement in fs_testGünther Noack
* Add enforce_fs() for defining and enforcing a ruleset in one step * In some places, dropped "ASSERT_LE(0, fd)" checks after create_ruleset() call -- create_ruleset() already checks that. * In some places, rename "file_fd" to "fd" if it is not needed to disambiguate any more. Signed-off-by: Günther Noack <gnoack3000@gmail.com> Link: https://lore.kernel.org/r/20260327164838.38231-12-gnoack3000@gmail.com [mic: Tweak subjet] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07selftests/landlock: Check that coredump sockets stay unrestrictedGünther Noack
Even when a process is restricted with the new LANDLOCK_ACCESS_FS_RESOLVE_UNIX right, the kernel can continue writing its coredump to the configured coredump socket. In the test, we create a local server and rewire the system to write coredumps into it. We then create a child process within a Landlock domain where LANDLOCK_ACCESS_FS_RESOLVE_UNIX is restricted and make the process crash. The test uses SO_PEERCRED to check that the connecting client process is the expected one. Includes a fix by Mickaël Salaün for setting the EUID to 0 (see [1]). Link[1]: https://lore.kernel.org/all/20260218.ohth8theu8Yi@digikod.net/ Suggested-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Günther Noack <gnoack3000@gmail.com> Link: https://lore.kernel.org/r/20260327164838.38231-11-gnoack3000@gmail.com Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07selftests/landlock: Audit test for LANDLOCK_ACCESS_FS_RESOLVE_UNIXGünther Noack
Add an audit test to check that Landlock denials from LANDLOCK_ACCESS_FS_RESOLVE_UNIX result in audit logs in the expected format. (There is one audit test for each filesystem access right, so we should add one for LANDLOCK_ACCESS_FS_RESOLVE_UNIX as well.) Signed-off-by: Günther Noack <gnoack3000@gmail.com> Link: https://lore.kernel.org/r/20260327164838.38231-10-gnoack3000@gmail.com Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07selftests/landlock: Test LANDLOCK_ACCESS_FS_RESOLVE_UNIXGünther Noack
* Extract common helpers from an existing IOCTL test that also uses pathname unix(7) sockets. * These tests use the common scoped domains fixture which is also used in other Landlock scoping tests and which was used in Tingmao Wang's earlier patch set in [1]. These tests exercise the cross product of the following scenarios: * Stream connect(), Datagram connect(), Datagram sendmsg() and Seqpacket connect(). * Child-to-parent and parent-to-child communication * The Landlock policy configuration as listed in the scoped_domains fixture. * In the default variant, Landlock domains are only placed where prescribed in the fixture. * In the "ALL_DOMAINS" variant, Landlock domains are also placed in the places where the fixture says to omit them, but with a LANDLOCK_RULE_PATH_BENEATH that allows connection. Cc: Justin Suess <utilityemal77@gmail.com> Cc: Tingmao Wang <m@maowtm.org> Cc: Mickaël Salaün <mic@digikod.net> Link[1]: https://lore.kernel.org/all/53b9883648225d5a08e82d2636ab0b4fda003bc9.1767115163.git.m@maowtm.org/ Signed-off-by: Günther Noack <gnoack3000@gmail.com> Link: https://lore.kernel.org/r/20260327164838.38231-9-gnoack3000@gmail.com Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07selftests/landlock: Replace access_fs_16 with ACCESS_ALL in fs_testGünther Noack
The access_fs_16 variable was originally intended to stay frozen at 16 access rights so that audit tests would not need updating when new access rights are added. Now that we have 17 access rights, the name is confusing. Replace all uses of access_fs_16 with ACCESS_ALL and delete the variable. Suggested-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Günther Noack <gnoack3000@gmail.com> Link: https://lore.kernel.org/r/20260327164838.38231-8-gnoack3000@gmail.com Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07landlock: Control pathname UNIX domain socket resolution by pathGünther Noack
* Add a new access right LANDLOCK_ACCESS_FS_RESOLVE_UNIX, which controls the lookup operations for named UNIX domain sockets. The resolution happens during connect() and sendmsg() (depending on socket type). * Change access_mask_t from u16 to u32 (see below) * Hook into the path lookup in unix_find_bsd() in af_unix.c, using a LSM hook. Make policy decisions based on the new access rights * Increment the Landlock ABI version. * Minor test adaptations to keep the tests working. * Document the design rationale for scoped access rights, and cross-reference it from the header documentation. With this access right, access is granted if either of the following conditions is met: * The target socket's filesystem path was allow-listed using a LANDLOCK_RULE_PATH_BENEATH rule, *or*: * The target socket was created in the same Landlock domain in which LANDLOCK_ACCESS_FS_RESOLVE_UNIX was restricted. In case of a denial, connect() and sendmsg() return EACCES, which is the same error as it is returned if the user does not have the write bit in the traditional UNIX file system permissions of that file. The access_mask_t type grows from u16 to u32 to make space for the new access right. This also doubles the size of struct layer_access_masks from 32 byte to 64 byte. To avoid memory layout inconsistencies between architectures (especially m68k), pack and align struct access_masks [2]. Document the (possible future) interaction between scoped flags and other access rights in struct landlock_ruleset_attr, and summarize the rationale, as discussed in code review leading up to [3]. This feature was created with substantial discussion and input from Justin Suess, Tingmao Wang and Mickaël Salaün. Cc: Tingmao Wang <m@maowtm.org> Cc: Justin Suess <utilityemal77@gmail.com> Cc: Kuniyuki Iwashima <kuniyu@google.com> Suggested-by: Jann Horn <jannh@google.com> Link[1]: https://github.com/landlock-lsm/linux/issues/36 Link[2]: https://lore.kernel.org/all/20260401.Re1Eesu1Yaij@digikod.net/ Link[3]: https://lore.kernel.org/all/20260205.8531e4005118@gnoack.org/ Signed-off-by: Günther Noack <gnoack3000@gmail.com> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://lore.kernel.org/r/20260327164838.38231-5-gnoack3000@gmail.com [mic: Fix kernel-doc formatting, pack and align access_masks] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-04-07selftests/landlock: Fix format warning for __u64 in net_testMickaël Salaün
On architectures where __u64 is unsigned long (e.g. powerpc64), using %llx to format a __u64 triggers a -Wformat warning because %llx expects unsigned long long. Cast the argument to unsigned long long. Cc: Günther Noack <gnoack@google.com> Cc: stable@vger.kernel.org Fixes: a549d055a22e ("selftests/landlock: Add network tests") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/r/202604020206.62zgOTeP-lkp@intel.com/ Reviewed-by: Günther Noack <gnoack3000@gmail.com> Link: https://lore.kernel.org/r/20260402192608.1458252-6-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>