The signal-scope denial callback identifies its target but not the
effective signal. This loses permission-probe signal zero and makes the
file-owner hook's zero sentinel ambiguous.
Append an int signal argument to the typed-BPF callback. Preserve sig,
including zero, in hook_task_kill(). In hook_file_send_sigiotask(),
translate signum zero to SIGIO at the producer, where its meaning is
known.
Carry the effective signal and target domain ID in a private,
stack-backed context consumed synchronously. This requires no allocation
or task reference in the interrupt-capable file-owner path. Gate this
context and the remaining scope-only domain IDs with CONFIG_TRACEPOINTS.
Keep the tracefs record and audit output unchanged.
Cc: Günther Noack <gnoack@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Fixes: bb91730f16 ("landlock: Add tracepoints for ptrace and scope denials")
Link: https://patch.msgid.link/20260918185036.608651-7-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
The ptrace denial callback identifies only the tracee. Current is the
tracer during hook_ptrace_access_check(), but it is the tracee during
PTRACE_TRACEME, where the parent is the actual tracer. A consumer
therefore cannot infer both parties from the existing arguments.
Append the actual tracer task to the typed-BPF callback: current for
hook_ptrace_access_check() and parent for hook_ptrace_traceme(). Carry
it with the tracee domain ID in a private ptrace context. Both hooks
keep the selected tasks alive through synchronous dispatch, so no extra
task reference is needed.
Keep the tracefs record unchanged. The new context is available only to
typed BPF, while same_exec continues to describe the tracer that owns
the denying policy.
Cc: Günther Noack <gnoack@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Fixes: bb91730f16 ("landlock: Add tracepoints for ptrace and scope denials")
Link: https://patch.msgid.link/20260918185036.608651-6-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
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: 01ce260f5c ("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>
Filesystem topology denials are rendered with an empty blockers value
because their blocker is identified by the request type instead of an
access mask.
Introduce the private struct landlock_blockers to carry the request type
and final missing access mask to filesystem and network denial
tracepoints. Copy both members into named trace-record fields, then use
the type to print change_topology for topology denials while preserving
symbolic access masks for ordinary denials.
The request type lets typed BPF consumers distinguish topology denials
from access denials. Keeping the native access mask in a pointer-reached
field also lets CO-RE adjust existing programs' load width if
access_mask_t grows.
Cc: Günther Noack <gnoack@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Fixes: 01ce260f5c ("landlock: Add landlock_deny_access_fs and landlock_deny_access_net")
Link: https://patch.msgid.link/20260918185036.608651-3-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Scope and ptrace denials follow a different code path (a domain
hierarchy check) than access-right denials, so they need dedicated
tracepoints with type-specific TP_PROTO arguments. Complete the denial
coverage with:
- landlock_deny_ptrace: ptrace access denied by a domain hierarchy
mismatch.
- landlock_deny_scope_signal: signal delivery denied by
LANDLOCK_SCOPE_SIGNAL.
- landlock_deny_scope_abstract_unix_socket: abstract unix socket access
denied by LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET.
TP_PROTO passes the raw kernel object (struct task_struct or struct
sock) for eBPF BTF access; the comm and sun_path string fields use
__print_untrusted_str() because they hold untrusted input. Unlike the
deny_access events, these omit the blockers field: each maps to exactly
one denial type named by the event, so the bitmask would always be zero.
Like the deny_access events they carry same_exec and logged.
Audit logs the task-targeted denials with generic field names (opid,
ocomm), but a strongly typed trace event can use role-prefixed names
(tracee_pid/tracee_comm, target_pid/target_comm) that match the mainline
task-name convention (sched_process_fork's parent_comm/child_comm) and
say whose name each field holds; a bare comm= would collide across
events. The abstract-unix-socket event reports peer_pid instead, a
tracepoint-only field with no audit counterpart.
A scope or ptrace verdict compares the subject domain against the other
party's domain, so each event also reports that other party's Landlock
domain (tracee_domain=, target_domain=, or peer_domain=); the subject
domain= alone does not let a consumer redo domain_is_scoped() or
domain_ptrace(). It is reported as a scalar ID rather than a domain
pointer: a domain object is immutable, but the other task can replace
its credential and free the domain that credential referenced, so a
stored foreign pointer could dangle before the event is consumed. The
scalar ID also honors the tracepoint no-nullable-pointer rule, since the
other party is frequently unsandboxed. Passing the foreign domain
hierarchy object so an eBPF consumer could walk the other party's
ancestry live would lengthen the RCU section on the shared denial path
and needs a deferred refcount put, so it is left as a future
enhancement. The relational domain-ID field (tracee_domain,
target_domain, or peer_domain) is trace-only and is not added to audit
records, so audit's denial format is unchanged by this series.
Cc: Günther Noack <gnoack@google.com>
Cc: Justin Suess <utilityemal77@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tingmao Wang <m@maowtm.org>
Link: https://patch.msgid.link/20260811094338.288094-14-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Tracepoint emission requires the denial framework (layer identification,
request validation) without depending on CONFIG_AUDIT. Separate the
denial logging infrastructure from the audit-specific code by
introducing a common log framework.
Create CONFIG_SECURITY_LANDLOCK_LOG, enabled by default when
CONFIG_AUDIT is set; a following commit extends it to CONFIG_TRACEPOINTS
when the first tracepoint consumer is added. Move the common framework
(the request types, the layer identification and request validation, and
the landlock_log_denial() and landlock_log_free_domain() entry points)
into log.c and log.h, and keep the audit-specific record formatting in
audit.c. log.o is built for CONFIG_SECURITY_LANDLOCK_LOG and audit.o for
CONFIG_AUDIT, so the common framework is available to a tracepoints-only
build. The entry points dispatch to no-op static inline audit stubs
without CONFIG_AUDIT, so the call sites stay unconditional. Rename the
former landlock_log_drop_domain() to landlock_log_free_domain() to match
the landlock_free_domain tracepoint added in a following commit.
landlock_log_denial() counts denials even without audit, so its
declaration and no-op stub are guarded by CONFIG_SECURITY_LANDLOCK_LOG,
not CONFIG_AUDIT; a CONFIG_AUDIT guard would expose the stub and clash
with log.c's definition in a tracepoints-only build.
Widen the ID allocation (id.o and the landlock_init_id() /
landlock_get_id_range() declarations) and the log-state representation
(the domain_exec and log_subdomains_off credential fields, the
landlock_hierarchy log fields, and the code that maintains them) from
CONFIG_AUDIT to CONFIG_SECURITY_LANDLOCK_LOG, so each field and its
writer share one guard and are available to tracing without audit
support.
Widen the denial-path state that feeds the per-denial logging decision
the same way, so the "logged" verdict is computed identically whether or
not CONFIG_AUDIT is set. Widening fown_layer is what keeps the
file-owner-signal path valid without audit: otherwise
hook_file_send_sigiotask() would leave layer_plus_one at zero, tripping
the is_valid_request() canary and dropping the LANDLOCK_SCOPE_SIGNAL
denial from tracing.
The ruleset-level quiet_masks stays on no CONFIG guard: it is builder
state validated and stored from user input, kept available so
LANDLOCK_ADD_RULE_QUIET flags are accepted and ignored, not rejected,
when CONFIG_SECURITY_LANDLOCK_LOG is disabled.
Cc: Günther Noack <gnoack@google.com>
Link: https://patch.msgid.link/20260811094338.288094-5-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
