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2026-08-17landlock: Add landlock_add_rule_fs and landlock_add_rule_net tracepointsMickaël Salaün5-2/+80
Add tracepoints for Landlock rule addition, landlock_add_rule_fs for filesystem rules and landlock_add_rule_net for network rules, so trace consumers can correlate filesystem objects and network ports with their rulesets. Both are emitted under the ruleset lock (asserted in TP_fast_assign) so an eBPF program reads the ruleset, including the rule just inserted, in a consistent snapshot. Add a version field to struct landlock_ruleset, gated on CONFIG_TRACEPOINTS like the id field and incremented under the ruleset lock on each successful landlock_add_rule(2), including when it only extends an existing rule's access rights. It fills the existing 4-byte hole after usage, so the struct does not grow. Pairing the ruleset ID with the version lets a later restrict_self event record the exact ruleset revision merged into a domain. Resolve the filesystem rule's absolute path with d_absolute_path() rather than the d_path() audit uses: d_absolute_path() produces namespace-independent paths that do not depend on the tracer's chroot state, making trace output deterministic regardless of mount namespace configuration. Distinguish the error cases as "<too_long>" (-ENAMETOOLONG) and "<unreachable>" (anonymous files or detached mounts). Also add __trace_print_untrusted_str(), a static inline helper in the header guarded by CREATE_TRACE_POINTS: it escapes separators, quotes, backslashes, and non-printable bytes via string_escape_mem() so an untrusted string (the path here, process names in later denial events) cannot inject field separators or control characters into the ftrace text output. Cc: Christian Brauner <brauner@kernel.org> 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/20260811094338.288094-9-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-17landlock: Add create_ruleset and free_ruleset tracepointsMickaël Salaün6-1/+48
Add the first Landlock tracepoints, for ruleset lifecycle: landlock_create_ruleset fires from the landlock_create_ruleset() syscall handler, and landlock_free_ruleset fires in free_ruleset() before the ruleset is freed. These tracepoints, and the ones added by the following commits, share a common design. Rather than one polymorphic event distinguished by a status field (as audit uses a shared record type with a "status=" field), each lifecycle transition and denial type gets its own event with a type-safe TP_PROTO, giving precise ftrace filtering by event name and type-safe eBPF access. TP_PROTO passes the object pointer and the fields are read from it in TP_fast_assign, so an eBPF program reads the full object state (rules, access masks, hierarchy) via BTF from a single pointer rather than from the flattened TP_STRUCT__entry fields. The whole cost is paid only when a tracer is attached; the static branch is not taken otherwise. Trace fields carry the bare access-right and scope names (read_file), reusing the audit name tables; audit prepends the category (fs.read_file), which the trace event name already conveys. The trace header's DOC comment documents the consistency and locking guarantees these events share. create_ruleset needs no lock because the ruleset is not yet shared (its file descriptor is not yet installed). The deallocation events use the "free_" prefix, not "drop_", because they fire when the object is actually freed. Add trace.c, built for CONFIG_TRACEPOINTS, which defines CREATE_TRACE_POINTS, and extend CONFIG_SECURITY_LANDLOCK_LOG to also be selected by CONFIG_TRACEPOINTS so the common log framework is available to a tracepoints-only build. Add an id field to struct landlock_ruleset, gated on CONFIG_TRACEPOINTS and assigned from landlock_get_id_range() at creation. Only the tracepoints consume it (audit identifies domains, not rulesets), so it does not exist in an audit-only build. The Landlock ID is a stable u64 that names the ruleset across the trace stream and uses the same scheme as audit, so a ruleset can be correlated between trace and audit records. 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/20260811094338.288094-8-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-17landlock: Consolidate access-right and scope names in a shared headerMickaël Salaün1-31/+53
Audit formats denial records with per-right name strings. A following commit adds trace events that print the same access and scope masks with __print_flags() and need the same names, but a trace event header cannot include Landlock-internal headers, so the names cannot be shared from the logging unit. Define the filesystem, network, and scope names once, as the _LANDLOCK_ACCESS_FS_NAMES, _LANDLOCK_ACCESS_NET_NAMES, and _LANDLOCK_SCOPE_NAMES lists in the public Landlock header. Each entry is a _LANDLOCK_NAME_ENTRY() the consumer expands: audit maps it to a "[bit] = name" array slot for an O(1) lookup, the trace events map it to a __print_flags() { mask, name } pair. The bit value comes only from the LANDLOCK_* UAPI constant each entry references, so every bit-to-name mapping has a single source and does not depend on entry order. The shared names are unprefixed; blocker_prefix() prepends the fs./net./scope. category for audit records, so the scope names move from inline literals to the shared table too. Audit records are unchanged. No functional change. Cc: Günther Noack <gnoack@google.com> Cc: Tingmao Wang <m@maowtm.org> Link: https://patch.msgid.link/20260811094338.288094-7-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-17landlock: Decouple the per-denial logging decision from CONFIG_AUDITMickaël Salaün3-95/+98
Until now, whether a denial is logged was decided inside landlock_audit_denial(): a per-execution flag check (log_same_exec or log_new_exec, selected by the credential's domain_exec bitmask), preceded by a LANDLOCK_LOG_DISABLED early return in landlock_log_denial() for domains an ancestor fully quieted. Factor that decision into a single is_denial_logged() helper called once by landlock_log_denial(), and pass its result to landlock_audit_denial() as a "logged" boolean. A following commit passes the same boolean to the deny tracepoints, so audit and tracing share one decision that stays correct as new log state is added, and a tracepoints-only build (CONFIG_AUDIT=n) computes it identically. Computing the logged verdict once in the shared helper makes audit and tracing apply identical filtering, so they cannot report different logged= values for the same denial as log controls grow. Move the LANDLOCK_LOG_DISABLED gate out of landlock_log_denial() into the decision so num_denials counts every denial, including those a domain quiets. This was previously masked: the only reader of num_denials is the audit "domain deallocated" record, emitted only for domains that reached LANDLOCK_LOG_RECORDED; a fully quieted domain never records, so its undercount was never observable. A following commit adds a free_domain tracepoint that reports num_denials, which needs the full count. This is not a functional change for audit: the logged decision and the audit_enabled gate are preserved, so the emitted records are identical. Cc: Günther Noack <gnoack@google.com> Link: https://patch.msgid.link/20260811094338.288094-6-mic@digikod.net Reviewed-by: Tingmao Wang <m@maowtm.org> [mic: Update copyright] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-17landlock: Split denial logging from audit into common frameworkMickaël Salaün17-570/+681
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>
2026-08-17landlock: Split struct landlock_domain from struct landlock_rulesetMickaël Salaün13-480/+403
Switch all domain users to the new struct landlock_domain type introduced by a previous commit, eliminating the conflation between mutable rulesets and immutable domains. landlock_merge_ruleset() now returns and allocates a struct landlock_domain, and the merge and inherit helpers move next to it; the former static insert_rule() is exported as landlock_store_rule() for its new caller across the translation-unit boundary. The merge destination is now a private struct landlock_domain still under construction (owned by the calling thread, not yet shared), so the merge and inherit helpers lock only the source ruleset: the previous lock of both destination and source collapses to a single mutex_lock(&src->lock). Rename the per-layer access-mask field from access_masks to handled_masks, naming it by the role it plays (the rights each layer handles) rather than by its type, paralleling the struct access_masks quiet_masks field. Drop the now domain-only fields (hierarchy, work_free, num_layers) from struct landlock_ruleset. The new struct landlock_domain field in cred.h pulls in domain.h, which includes audit.h, which previously included cred.h, forming an include cycle. Break it by having audit.h forward-declare the struct landlock_cred_security and struct landlock_hierarchy it uses instead of including cred.h. Cc: Günther Noack <gnoack@google.com> Cc: Tingmao Wang <m@maowtm.org> Link: https://patch.msgid.link/20260811094338.288094-4-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-17landlock: Move domain query functions to domain.cMickaël Salaün5-188/+201
Grouping domain-specific code in one compilation unit reduces coupling between domain and ruleset implementations. Move the access-check functions that only operate on a domain (rule lookup, layer unmasking, layer-mask init, access-mask union) from ruleset.[ch] to domain.[ch]. They evaluate whether a domain grants a requested access during the pathwalk and network checks and do not modify the domain. The merge and inherit chain stays in ruleset.c for now because it calls the static create_ruleset() allocator; a following commit moves it once the domain type switch eliminates that dependency. No behavioral change. The functions move with unchanged signatures and bodies. Cc: Günther Noack <gnoack@google.com> Cc: Tingmao Wang <m@maowtm.org> Link: https://patch.msgid.link/20260811094338.288094-3-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-17landlock: Prepare ruleset and domain type splitMickaël Salaün5-60/+202
Rulesets and domains serve fundamentally different purposes: a ruleset is mutable and user-facing, created by landlock_create_ruleset(), while a domain is immutable after construction and enforced on tasks via landlock_restrict_self(). Today both are represented by struct landlock_ruleset, which conflates mutable and immutable state in a single type: the lock field is unused by domains, the hierarchy field is unused by rulesets, and lifecycle functions must handle both cases. Prepare for a clean type split by introducing two new structures: - struct landlock_rules: the red-black tree roots and rule count, shared by both rulesets and domains. Decoupling rule storage from the domain API lets the backing data structure change independently (e.g. to a hash table, cf. [1]). - struct landlock_domain: the immutable domain enforced on tasks, with no lock field because its rules and access masks are fixed once construction completes. The name reflects the role, not the internal data structure. Add the domain lifecycle helpers (landlock_get_domain(), landlock_put_domain(), landlock_put_domain_deferred()) and move domain.o from landlock-$(CONFIG_AUDIT) to landlock-y, because these are needed unconditionally, not just for audit logging. No behavioral change. The new types and lifecycle functions are not yet used by any caller. Cc: Günther Noack <gnoack@google.com> Link: https://patch.msgid.link/20250523165741.693976-1-mic@digikod.net [1] Link: https://patch.msgid.link/20260811094338.288094-2-mic@digikod.net Reviewed-by: Tingmao Wang <m@maowtm.org> [mic: Update copyright] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-15apparmor: fix deadlock in complain-mode change_hatJohn Johansen3-14/+37
The use of change_hat when in complain mode can cause a deadlock when the hat doesn't exist and a new learning profile is created for the missing profile. This is because change_hat() has taken the lock to search the hat list and creating the new learning profile needs to take the lock to add it to the list. From the bug report: Originally found in 7.0.0 in LTS ubuntu 26.04 with pam_apparmor + su in complain mode set to change hats. Then verified in newest available vanilla kernel I've compiled to see if still present: 7.2-rc7 vanilla -> affected checked also some other kernels: 6.18.44 vanilla -> affected 6.12.95 with debian patches -> unaffected On systems without bug (for example 6.12.95 debian) it just prints: aa_change_hat rc=0 On systems with bug, the executable always hangs, prints nothing and becomes unkillable. (And once stuck this way, it will cause any further hat changes to also cause the changing process to get stuck) Then in syslog you can find hint about cause: kernel: INFO: task hat:3409 blocked for more than 483 seconds. kernel: Not tainted 7.2.0-rc7 #1 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kernel: task:hat state:D stack:0 pid:3409 tgid:3409 ppid:2605 task_flags:0x400000 flags:0x00080800 kernel: Call Trace: kernel: <TASK> kernel: __schedule+0x48f/0xfe0 kernel: schedule+0x27/0xa0 kernel: schedule_preempt_disabled+0x15/0x30 kernel: __mutex_lock.constprop.0+0x569/0xa10 kernel: aa_new_learning_profile+0x15f/0x210 kernel: build_change_hat+0x19f/0x3b0 kernel: change_hat.isra.0+0x5dd/0xd60 kernel: aa_change_hat+0x2f3/0x710 kernel: aa_setprocattr_changehat+0x121/0x1f0 kernel: do_setattr+0x28c/0x340 kernel: apparmor_setselfattr+0x20/0x50 kernel: security_setselfattr+0xf6/0x110 kernel: __x64_sys_lsm_set_self_attr+0x53/0x90 kernel: do_syscall_64+0xdd/0x5e0 kernel: ? __mod_memcg_lruvec_state+0xfd/0x260 kernel: ? lruvec_stat_mod_folio+0x8d/0xd0 kernel: ? __folio_mod_stat+0x2d/0x90 kernel: ? map_anon_folio_pte_nopf+0xd1/0x1f0 kernel: ? do_anonymous_page+0x184/0xa10 kernel: ? __handle_mm_fault+0x805/0x870 kernel: ? count_memcg_events+0xef/0x230 kernel: ? handle_mm_fault+0x1f0/0x2f0 kernel: ? do_user_addr_fault+0x2bb/0x7b0 kernel: ? do_syscall_64+0x94/0x5e0 kernel: ? exc_page_fault+0x75/0x160 kernel: entry_SYSCALL_64_after_hwframe+0x76/0x7e kernel: RIP: 0033:0x7f815e134c8d kernel: RSP: 002b:00007fff6df94ea8 EFLAGS: 00000246 ORIG_RAX: 00000000000001cc kernel: RAX: ffffffffffffffda RBX: 0000556d8c81d040 RCX: 00007f815e134c8d kernel: RDX: 0000000000000046 RSI: 0000556d8c81d040 RDI: 0000000000000064 kernel: RBP: 00007fff6df94ef0 R08: 00007f815e212ac8 R09: 000000000000000c kernel: R10: 0000000000000000 R11: 0000000000000246 R12: 0000556d8c81d010 kernel: R13: 0000000000000026 R14: 0000000000000046 R15: 0000000000000064 kernel: </TASK> kernel: INFO: task hat:3409 is blocked on a mutex likely owned by task hat:3409. To fix the issue, lift the locking out of the core of aa_new_learning_profile(), introduce a wrapper function that takes the lock where needed, and have build_change_hat() call the core function that no longer takes the lock. In addition fix 4 other issues introduced by commit 32e92764d6f8d ("apparmor: grab ns lock and refresh when looking up changehat child profiles") - aa_get_profile_rcu() was replaced-by: aa_get_profile without the accompanying rcu_dereference_protected() - an extra aa_get_label(label) was introduced at the start of change_hat() without an accompanying aa_put_label() causing a reference count leak. - a reference count leak was introduced in the label_is_stale(label) case, where the newest profile would be leaked instead of the label passed to the function. - a potential UAF when the lookup walks up the tree with new_ns != ns the new label reference is put, and then used for the next lookup. The mutex_lock, will block replacement, and removal in the locked ns. However there are two cases where putting the reference can result in the label being freed even with the lock held. 1. the label does not have a list reference (possible for temporary or special profiles) in which case the put can trigger the cleanup. 2. the new label reference is in a different namespace, which does not have a lock held on it. This extends case 1 to also include replacement, and removal that could be occurring in the namespace new is in. Reported-by: Martin Petricek <mp@petricek.net> Link: https://lists.ubuntu.com/archives/apparmor/2026-August/014907.html Fixes: 32e92764d6f8d ("apparmor: grab ns lock and refresh when looking up changehat child profiles") Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-15landlock: Add LANDLOCK_RESTRICT_SELF_NO_NEW_PRIVSJustin Suess4-11/+30
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 Suess1-4/+4
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>
2026-08-15landlock: Require LANDLOCK_ACCESS_FS_MAKE_REG for whiteout creationGünther Noack2-9/+55
Whiteout objects are used in the upper layer of an OverlayFS to indicate that the file with this name does not exist in the unified view, even if it is present in one of the lower layer file systems. For the userspace implementations of OverlayFS (fuse-overlayfs), whiteout objects can be created from userspace as well: * mknod(2) with S_IFCHR and makedev(0, 0) * renameat2(2) with RENAME_WHITEOUT, creating the whiteout in the old place of the moved file. This commit guards whiteout creation in both of these cases with LANDLOCK_ACCESS_FS_MAKE_REG. Whiteout objects are *not* considered character devices and are not bound to a driver. LANDLOCK_ACCESS_FS_MAKE_REG describes the same permission class as a whiteout object: creating one is the only S_IFCHR creation that the VFS exempts from CAP_MKNOD, so it is as unprivileged as creating a regular file, while LANDLOCK_ACCESS_FS_MAKE_CHAR and LANDLOCK_ACCESS_FS_MAKE_BLOCK keep meaning the creation of devices that expose a kernel interface [1]. For the mknod(2) case, introduce a Landlock erratum. The creation of whiteout objects through mknod(2) was previously guarded using LANDLOCK_ACCESS_FS_MAKE_CHAR, and it is now guarded using LANDLOCK_ACCESS_FS_MAKE_REG. For the renameat2(2) case, fix a bug: Before this commit, renameat2(2) with RENAME_WHITEOUT would create a directory entry even when all LANDLOCK_ACCESS_FS_MAKE_* rights were denied. This does not affect normal renames within layered OverlayFS mounts: When doing a regular rename() on a mounted fuse-overlayfs, it is the fuse-overlayfs daemon that exercises renameat2() with RENAME_WHITEOUT, and only the Landlock domain of that daemon is checked there. Suggested-by: Christian Brauner <brauner@kernel.org> Suggested-by: Mickaël Salaün <mic@digikod.net> Cc: stable@vger.kernel.org Fixes: cb2c7d1a1776 ("landlock: Support filesystem access-control") Depends-on: 49c9e09d9610 ("landlock: Fix handling of disconnected directories") Depends-on: fe72ce6710cb ("landlock: Add errata documentation section") Signed-off-by: Günther Noack <gnoack@google.com> Link: https://patch.msgid.link/20260720.chow9ohYie5b@digikod.net [1] Link: https://patch.msgid.link/20260813093157.1436894-3-gnoack@google.com [mic: Record why LANDLOCK_ACCESS_FS_MAKE_REG is the matching right, and add link(2) to the user doc] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-14landlock: Harden sock_is_scoped() against file-less socketsMickaël Salaün1-0/+11
sock_is_scoped() dereferences other->sk_socket->file->f_cred to read the peer's Landlock domain when evaluating LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET, without first checking that the peer has a backing socket and file. hook_unix_find() performs the same dereference for LANDLOCK_ACCESS_FS_RESOLVE_UNIX and does guard it. Guard it here too and treat a peer with no backing file, such as a kernel socket created by sock_create_kern(), as unscoped. This is defensive hardening, not a fix for a reachable bug. The unix_stream_connect() and unix_may_send() hooks run with the peer held under unix_state_lock() and only after the AF_UNIX core has excluded SOCK_DEAD, and no in-tree code binds a file-less AF_UNIX socket to an abstract address, so other->sk_socket->file is always valid at these call sites today. Cc: Günther Noack <gnoack@google.com> Link: https://patch.msgid.link/20260703152750.2022878-1-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2026-08-10apparmor: constify aa_label parameters on read-only query helpersJohn Johansen2-20/+23
Several label helpers only read from their struct aa_label * arguments: they compare labels, test subset relationships, or check the mediation bitmask, all via direct field/index access. Mark those parameters const struct aa_label * to document intent and let the compiler enforce that the label is not modified. The converted functions are: - label_mediates(), label_mediates_safe() - aa_label_cmp() (and its vec_cmp() helper) - __aa_label_next_not_in_set(), aa_label_is_subset(), aa_label_is_unconfined_subset() - __aa_subj_label_is_cached() - aa_label_next_confined(), aa_label_next_in_merge() These all access the label through direct indexing or manual iterators rather than the label_for_each()/fn_for_each() macros, which are not const-correct and so gate the majority of the remaining label consumers (the print, match, and permission-check paths) from being constified. No functional change. Signed-off-by: John Johansen <john.johansen@canonical.com> Assisted-by: Claude:claude-opus-4.8
2026-08-10apparmor: constify aa_dfa parameters on read-only compute pathsJohn Johansen8-32/+37
Most uses of aa_dfa a read-only walking of the dfa. Have the compiler enforce this. Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: constify aa_profile parameters on read-only compute pathsJohn Johansen10-23/+25
A number of functions take a struct aa_profile * argument that is only ever read from: they compute DFA matches or apply the profile's mode flags without modifying the profile, taking a reference on it, or touching its embedded label. Mark those parameters const struct aa_profile * to document intent and let the compiler enforce it. The converted functions are the permission "compute" path plus a few pure readers: - aa_apply_modes_to_perms(), aa_profile_match_label() - AUDIT_MODE() - aa_label_match() and its match_component()/label_compound_match()/ label_components_match() helpers (label.c) - match_component()/label_compound_match()/label_components_match()/ label_match()/change_profile_perms()/aa_xattrs_match() (domain.c) - match_iface()/match_addr_iface()/match_addr_iface_label()/ skb_match_to_sk()/skb_match_to_cmd() (af_inet.c) - aa_profile_capget(), path_flags(), profile_query_cb() The remaining aa_profile * parameters cannot be made const: the audit path stores &profile->label into the owned, refcounted apparmor_audit_data.subj_label/peer fields, and the domain/lifecycle paths take references on the profile's embedded label (aa_get_label()/aa_get_newest_label()/aa_get_profile()) or write profile fields. No functional change. Signed-off-by: John Johansen <john.johansen@canonical.com> Assisted-by: Claude:claude-opus-4.8
2026-08-10apparmor: constify aa_perms parameters that are read-onlyJohn Johansen6-10/+11
Several functions take a struct aa_perms * argument that is only ever read from and never modified through the pointer. Mark those parameters const struct aa_perms * to document intent and let the compiler enforce that the permission set is not mutated. The converted functions are: - aa_check_perms() - aa_do_perms() - do_perms() (af_inet) - match_label() (af_unix) - verify_perm() - aa_perms_accum() / aa_perms_accum_raw() (@addend only) No functional change. Signed-off-by: John Johansen <john.johansen@canonical.com> Assisted-by: Claude:claude-opus-4.8
2026-08-10apparmor: drop use of _confined variant for iterationJohn Johansen1-7/+7
In preparation for allowing unconfined to be replaced and mediate select rules drop use of the _confined variant for iteration in the mount code. The RULE_MEDIATES() check will continue to allow unconfined profile mediation to be skipped unless it is replaced and is given mount rules. Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: refactory mount to use check_permsJohn Johansen4-168/+144
Move the mount permissions check to use the common backend aa_check_perms() to check permissions. This will make it so caching, audit, complain, logic can be handled consistently in a single place. Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: fix auditing of mount binary dataJohn Johansen1-2/+2
AppArmor only mediates non-binary mount data, and should only audit the mount data if it is non-binary. Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: add audit mode to provide a mechanism to silence complain messagesJohn Johansen4-10/+22
Complain messages can be very noisy and fill the logs quickly. Allow complain (allow) messages to be silenced separate from denied messages. Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: mark static tables and structs as read onlyJohn Johansen8-20/+22
static tables, and structs that are initialized as part of their data section or during init should be read only to protect against accidental or malicous changes. Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: fix error debug output in fn_label_buildJohn Johansen1-2/+2
checking PTR_ERROR() is not correct to just determine if any error occured, instead use the IS_ERR macro and also output the PTR_ERR as part of the debug message. Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: make table entry count last enum for static tablesJohn Johansen3-5/+5
Instead of keeping an external define for the various tables indexed by an enum, make the size the last entry of the enum so the table size will get updated correctly with changes to the enum. Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: fix race condition in label replacementJohn Johansen1-12/+48
label replacement can result in the need for locking on two separate trees. Currently this is done by locking the tree to remove and then the tree to add to. For compound labels the race can result in the old label proxy pointing to the the new label that lost the race and that was not inserted in to the new tree. This does not break mediation, but it does result in a task that will not update its profile correctly on future mediation, and that will leak its refcount due to a circular reference in its proxy, resulting in a memory leak. Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: refactor xattr attachment, to take the file pathJohn Johansen1-15/+19
The full bprm does not need to be passed into xattrs_match, so only pass in the path, and propagate the change backup the call stack until bprm is actually needed. Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: fix unconfined user namespace restriction forced stackJohn Johansen1-26/+54
If a task is already confined by a stack the unprivileged transition restriction on unconfined is not correctly, applied. This results in an escape if two transitions through an unconfined profile can be executed. Fix this by pushing the check into the per profile label build. The check will always be done against unconfined and result in a stack of just the unconfined component when necessary. Fixes: 2d9da9b188b8 ("apparmor: allow restricting unprivileged change_profile") Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: reserve mediation class for packet mediationJohn Johansen2-1/+2
Packet mediation is going to be added in the future, reserve a class for it. Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: move sock_rcv_skb() next to inet_conn_requestJohn Johansen1-36/+33
both of these fns are using ifdef CONFIG_NETWORK_SECMARK and related to AppArmor's secmark based mediation, so move them together. Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: move netfilter functions next to the LSM network operationsJohn Johansen1-44/+46
Make sure all the network mediation hooks are next to each other in a logical block. This just makes it easier to read/understand the network mediation code. Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: refactor network socket mediation to support compatibilityJohn Johansen1-8/+10
Make it easier for distros to support the network backwards compat patch by refactoring the code to minimize the changes needed. Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: push inet mediation into profile callbacks, and improve auditingJohn Johansen2-13/+497
Continue preparing for fine grained inet mediation by setting up the stacked mediation callback. This lifts address mapping and audit context setup out of the stacking loop and pushing the mediation down into the callback fn. While this patch sets up the structure for fine grained mediation it does not change mediation and the callback fns only call the default mediation that will be used when fine grained inet mediation is not available. Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: refactor network sock mediation in preparation for inet mediationJohn Johansen6-22/+190
Refactor network mediation, introducing the stub code for the fine grained inet mediation. This is a preparatory step and does not change mediation. Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: make MEDIATES_AF_UNIX its own fnJohn Johansen3-9/+13
Hide the functionality of determinig unix mediation behind its own fn so it is easier to adjust the test in the future as it has different requirements than the other socket mediation. Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: fix error handling for copy_from_user in policy_updateJohn Johansen1-3/+3
copy_from_user does not return an error code and the check should be setting the error code. Fixes: 8b236f99edf8 ("apparmor: Initial support for compressed policies") Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-10apparmor: fix out-of-bounds write when null terminating a label vecHyunwoo Kim1-3/+3
aa_vec_unique() null terminates at vec[n - dups] when VEC_FLAG_TERMINATE is passed. If the components are all distinct no duplicates are dropped, dups is 0 and the terminator goes to vec[n], so the caller has to provide room for n + 1 entries. aa_label_strn_parse() sets up its vector with vec_setup(profile, vec, len, gfp) and then calls aa_vec_unique(vec, len, VEC_FLAG_TERMINATE), but vec_setup() does not reserve the terminator entry. Up to LOCAL_VEC_ENTRIES it uses the local array of LOCAL_VEC_ENTRIES pointers, above that it allocates exactly len pointers. The terminator therefore lands one entry past the end of the local array when len is LOCAL_VEC_ENTRIES, and one entry past the end of the allocation when len is larger. len comes from the number of "//&" separated components in the label name and label_count_strn_entries() does not bound it. An unprivileged task reaches the parse by writing to /proc/self/attr/apparmor/current or through lsm_set_self_attr(2), both of which go through do_setattr(), and the name is parsed before the change_profile permission is checked. The query_label() path behind the securityfs .access file, which is mode 0666, performs no permission check at all. Every component has to resolve to a loaded profile, so a system with policy loaded is required. The other two VEC_FLAG_TERMINATE users work on a label vec that aa_label_alloc() has already sized with "+ 1 for null terminator entry on vec". Reserve the same entry in vec_setup() and DEFINE_VEC(). Passing len + 1 from the caller instead would move len == LOCAL_VEC_ENTRIES out of the local array and into kzalloc(). Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels") Cc: stable@vger.kernel.org Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-09apparmor: fix integer overflow in verify_tags() bounds checkFabrice Derepas1-1/+1
verify_tags() validates the tagset table unpacked from a policy blob. For each set it reads a count and checks that advancing the index by that count stays inside sets.table[]: u32 cnt = tags->sets.table[i]; if (i+cnt >= tags->sets.size) { i, cnt and sets.size are all u32, so i+cnt is evaluated modulo 2^32. sets.table[] is filled by unpack_tagsets() with aa_unpack_u32(), so every entry is a raw unbounded 32-bit word taken from the policy blob, and verify_tags() is the function that is supposed to validate it. A count close to U32_MAX makes the sum wrap to a small value, the guard passes, and the inner loop then walks sets.table[++i] past the end of the kcalloc(size, sizeof(u32)) allocation. Note that sets.size is bounded by 65535, because unpack_tagsets() reads it with aa_unpack_array() as a u16, so the wrap cannot be reached by growing the table; it is reached purely through the attacker-supplied count. With sets.size = 2 and sets.table = { 0, 0xffffffff }: i = 0: cnt = 0, guard 0 + 0 >= 2 is false, inner loop does not run i = 1: cnt = 0xffffffff, guard (1 + 0xffffffff) mod 2^32 == 0 >= 2 is false, so the guard is bypassed and the inner loop reads sets.table[2] -- one element past a two element allocation The walk continues until an out-of-bounds value happens to be >= hdrs.size or the access faults, so a crafted policy yields an out-of-bounds read on the policy load path (aa_replace_profiles -> aa_unpack -> unpack_policydb -> unpack_tags -> verify_tags). unpack_tags() runs before the perms and DFA tables are unpacked, so no other table needs to be well formed to reach it. Policy load is gated by aa_may_manage_policy(), which checks CAP_MAC_ADMIN relative to the subject's own user namespace rather than the init user namespace, so with the default unprivileged_userns_apparmor_policy=1 the path is reachable from an unprivileged task in a matched-level nested namespace, not only by a globally privileged one. Perform the addition in u64 so that it cannot wrap, restoring the intended i + cnt < sets.size guarantee. Fixes: 3d28e2397af7 ("apparmor: add support loading per permission tagging") Signed-off-by: Fabrice Derepas <fabrice.derepas@canonical.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-08smack: fix cred UAF in smack_file_send_sigiotask()Jann Horn1-1/+1
When inspecting the credentials of another task, objective credentials (->real_cred, accessed with __task_cred()) must always be used. Accessing ->cred on a non-current task is forbidden unless that task is being created or destroyed; a task is allowed to change its own ->cred pointer with no synchronization, and changing ->cred should only affect the current syscall. smack_file_send_sigiotask() was accessing both sets of credentials: First tsk->cred, then __task_cred(tsk). Fix it, always access the objective credentials here. I have tested that this bug can lead to a KASAN-reported UAF of struct cred in smack_file_send_sigiotask(), and that this fix prevents the race. Cc: stable@vger.kernel.org Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2026-08-07apparmor: optimize current_label_crit_section() with needputJohn Johansen5-58/+84
The {begin,end}_current_label_crit_section() has the same issue as the {__begin,__end} version. That is the check to see if the label has been updated in the end check forces an unnecessary memory barrier. We can optimize this the same way we do with the {__begin,__end} variant by passing in a local variable that carries the state information from the begin check into the end check. No functional change. Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-06apparmor: fix cred UAF caused by begin_current_label_crit_section()Jann Horn3-9/+39
AppArmor's begin_current_label_crit_section() is a scary function called from lots of LSM hooks (in particular VFS/socket-related ones) that checks if the label referenced by the current creds is marked FLAG_STALE, and if so, attempts to use aa_replace_current_label() to replace the creds with an updated version that uses a new label. The first problem with this is that it would directly lead to UAF of `struct cred` if anything in the kernel takes a pointer to the current creds and accesses these past a security hook invocation that replaces creds, like so: ``` const struct cred *cred = current_cred(); alloc_file_pseudo(...); uid_t uid = cred->euid; ``` I don't know if anything in the kernel actually does this, but I think it is very surprising that this pattern could lead to UAF. The second problem is that things go wrong when aa_replace_current_label() runs with overridden credentials. aa_replace_current_label() bails out if `current_cred() != current_real_cred()` (mirroring the check in proc_pid_attr_write()), but this check can't actually reliably detect overridden credentials because the overridden creds can be the same as the objective creds. So in approximately the following scenario, things go wrong: 1. task begins with <creds A> (as both objective and subjective creds), with refcount=2 2. task grabs an extra reference on <creds A> for overriding 3. task calls override_creds(<creds A>), which returns a pointer to the old subjective creds (<creds A>) 4. task enters AppArmor LSM hook 5. AppArmor checks that objective/subjective creds are equal 6. AppArmor replaces both cred pointers with <creds B> and drops 2 refs on <creds A> 7. task leaves AppArmor LSM hook 8. task calls revert_creds(<creds A>) 9. now task->cred is <creds A> while task->real_cred is <creds B>, but the task_struct logically holds two references to <creds B> 10. another task drops the extra reference on <creds A> that was used for overriding, refcount drops to 0 11. now task->real_cred points to freed creds At this point, any access to current_cred() will be UAF. I have a test case where I run aa-disable on a profile while a process using that profile is blocked on splice() from a FUSE passthrough file into a full pipe; after the profile update, the pipe becomes empty, splice() resumes, the credentials go out of sync, and a subsequent getuid() syscall results in a KASAN UAF splat. To fix this, instead of directly replacing creds, do it via task_work that will run at the end of the current syscall. (The point in time at which the cred replacement happens should have no correctness impact; it is just a performance optimization to avoid unnecessarily touching the refcount of the new label.) Note that AppArmor still performs direct cred replacements in the sb_pivotroot LSM hook after this change, and that direct cred replacements can still happen in VFS ->write() callbacks via proc_pid_attr_write(). There are two options for what to do with aa_dup_task_ctx(): Either explicitly reset new->label_replacement_pending after the entire aa_task_ctx has been copied, or switch to manually copying members over. I am switching to manually copying members over because that should make bugs more obvious. Cc: stable@vger.kernel.org Fixes: c75afcd153f6 ("AppArmor: contexts used in attaching policy to system objects") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-06apparmor: use SEND_SIG_NOINFO instead of NULL in aa_audit()Oleg Nesterov1-1/+1
SEND_SIG_NOINFO is defined as ((struct kernel_siginfo *) 0), so passing NULL works, but: - this works "by accident" and looks as if the caller doesn't understand the signal sending API. - more importantly, this hides the usage of SEND_SIG_NOINFO from grep, and this is really bad. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Georgia Garcia <georgia.garcia@canonical.com> Signed-off-by: John Johansen <john.johansen@canonical.com>
2026-08-05Merge tag 'selinux-pr-20260805' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinuxLinus Torvalds4-32/+136
Pull selinux fixes from Paul Moore: - Continue to improve the validation of SELinux policies during load - Fix a SELinux regression caused by bpffs changes in v7.2-rc1 - Fix a SELinux preformance regression caused by SELinux changes in v7.2-rc1 * tag 'selinux-pr-20260805' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: check level category sets once at load time selinux: require every boolean value to be defined selinux: reject an unclaimed class value in security_get_classes() selinux: require a class's permission values to cover its permission count selinux: do not cancel a policy conversion that never started selinux: bpf: check SBLABEL_MNT before isec init selinux: reject a class permission count below its inherited common selinux: reject a permission value exceeding the class permission count
2026-08-04ima: measure userspace policy writes before parsingEnrico Bravi4-0/+30
When a signed policy is not mandatory, userspace can write IMA policy rules directly to the securityfs policy file: echo -e "measure func=BPRM_CHECK mask=MAY_EXEC\n" \ "audit func=BPRM_CHECK mask=MAY_EXEC\n" \ > /sys/kernel/security/ima/policy or by cat'ing the entire IMA custom policy file: cat ima-policy-file > /sys/kernel/security/ima/policy Because these rules originate from userspace and cross the userspace/kernel trust boundary, measure the raw write buffer before parsing, regardless of whether the new policy will be accepted or not. This can be caught when 'measure func=POLICY_CHECK' is enabled (e.g., ima_policy=tcb). The measurement template is forced to ima-buf. This follows the "measure & load" paradigm, exposing potential bugs in the policy code and detecting attempts to corrupt IMA. It also completes the POLICY_CHECK hook, which already measures partial policy load by file. To verify the template data hash value, convert the buffer policy data to binary: grep "ima_policy_written" \ /sys/kernel/security/integrity/ima/ascii_runtime_measurements | \ tail -1 | cut -d' ' -f 6 | xxd -r -p | sha256sum Suggested-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Enrico Bravi <enrico.bravi@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-08-04ima: add critical data measurement for loaded policyEnrico Bravi4-3/+99
IMA policy can be written multiple times in the securityfs policy file at runtime if CONFIG_IMA_WRITE_POLICY=y. When IMA_APPRAISE_POLICY is required, the policy needs to be signed to be loaded, writing the absolute path of the file containing the new policy: echo /path/of/custom_ima_policy > /sys/kernel/security/ima/policy When this is not required, policy can be written directly, rule by rule: echo -e "measure func=BPRM_CHECK mask=MAY_EXEC\n" \ "audit func=BPRM_CHECK mask=MAY_EXEC\n" \ > /sys/kernel/security/ima/policy In this case, a new policy can be loaded without being measured or appraised. Add a new critical data record to measure the textual policy representation when it becomes effective. Include in the architecture-specific policy the new critical data record only when it is not mandatory to load a signed policy. Additionally, enable the policy serialization code even when CONFIG_IMA_READ_POLICY=n. To verify the template data hash value, convert the buffer policy data to binary: grep "ima_policy_loaded" \ /sys/kernel/security/integrity/ima/ascii_runtime_measurements | \ tail -1 | cut -d' ' -f 6 | xxd -r -p | sha256sum Signed-off-by: Enrico Bravi <enrico.bravi@polito.it> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-08-04ima: Instantiate file_truncate and path_truncate hooksMimi Zohar1-0/+39
Instantiate the file_truncate and path_truncate LSM hooks to reset the action cache flags (IMA_DONE_MASK) as soon as truncation is requested, so the file, based on policy, is re-collected, re-measured, re-audited, and re-appraised on next access. Tested-by: Frederick Lawler <fred@cloudflare.com> Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-08-04security: ima: rename boot_aggregate when ima is initialised at late_syncJonathan McDowell3-5/+14
The Linux IMA (Integrity Measurement Architecture) subsystem used for secure boot, file integrity, or remote attestation cannot be a loadable module for few reasons listed below: o Boot-Time Integrity: IMA’s main role is to measure and appraise files before they are used. This includes measuring critical system files during early boot (e.g., init, init scripts, login binaries). If IMA were a module, it would be loaded too late to cover those. o TPM Dependency: IMA integrates tightly with the TPM to record measurements into PCRs. The TPM must be initialized early (ideally before init_ima()), which aligns with IMA being built-in. o Security Model: IMA is part of a Trusted Computing Base (TCB). Making it a module would weaken the security model, as a potentially compromised system could delay or tamper with its initialization. IMA must be built-in to ensure it starts measuring from the earliest possible point in boot which inturn implies TPM must be initialised and ready to use before IMA. Unfortunately some TPM drivers (such as Arm FF-A, or SPI attached TPM devices) are not reliably available during the initcall_late stage, resulting in a log error: ima: No TPM chip found, activating TPM-bypass! To address this issue, IMA_INIT_LATE_SYNC is introduced. However, a remote attestation service cannot determine when IMA has been initialized because the boot_aggregate measurement name remains unchanged, even though IMA is initialized later at late_initcall_sync when IMA_INIT_LATE_SYNC is enabled. Therefore, use a distinct boot_aggregate name when IMA_INIT_LATE_SYNC is enabled, allowing the remote attestation service to identify when IMA has been initialized. Signed-off-by: Jonathan McDowell <noodles@meta.com> [yeoreum.yun@arm.com: modified to align with the IMA_INIT_LATE_SYNC change] Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-08-04ima: fix out-of-bounds read in xattr_verify()Lincoln Wallace1-2/+7
The digest-length check in xattr_verify() mixes int and size_t: if (xattr_len - sizeof(xattr_value->type) - hash_start >= iint->ima_hash->length) sizeof() yields size_t, so the usual arithmetic conversions promote the whole left-hand side to unsigned 64-bit before the subtraction runs. For a truncated xattr this underflows instead of going negative: a 1-byte IMA_XATTR_DIGEST_NG xattr (xattr_len == 1, hash_start == 1) turns "1 - 1 - 1" into SIZE_MAX, which is trivially >= ima_hash->length. The check then passes and the following memcmp() reads iint->ima_hash->length bytes starting past the end of the buffer vfs_getxattr_alloc() allocated for it. Nothing upstream clamps xattr_len back into a safe range first: ima_get_hash_algo() only special-cases xattr_len < 2 to pick a default algorithm, and evm_verifyxattr() returns INTEGRITY_UNKNOWN rather than failing when no HMAC key is loaded, so a truncated security.ima value reaches the length check as-is. Rewrite the comparison so every operand stays a signed int and no implicit conversion to size_t can occur. Fixes: 3ea7a56067e6 ("ima: provide hash algo info in the xattr") Cc: stable@vger.kernel.org Signed-off-by: Lincoln Wallace <locnnil0@gmail.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-08-04security: ima: introduce IMA_INIT_LATE_SYNC optionYeoreum Yun2-0/+14
To generate the boot_aggregate log in the IMA subsystem with TPM PCR values, the TPM driver must be built as built-in and must be probed before the IMA subsystem is initialized. However, when the TPM device operates over the FF-A protocol using the CRB interface, probing fails and returns -EPROBE_DEFER if the tpm_crb_ffa device — an FF-A device that provides the communication interface to the tpm_crb driver — has not yet been probed. To ensure the TPM device operating over the FF-A protocol with the CRB interface is probed before IMA initialization, the following conditions must be met: 1. The corresponding ffa_device must be registered, which is done via ffa_init(). 2. The tpm_crb_driver must successfully probe this device via tpm_crb_ffa_init(). 3. The tpm_crb driver using CRB over FF-A can then be probed successfully. (See crb_acpi_add() and tpm_crb_ffa_init() for reference.) Unfortunately, ffa_init(), tpm_crb_ffa_init(), and crb_acpi_driver_init() are all registered with device_initcall, which means crb_acpi_driver_init() may be invoked before ffa_init() and tpm_crb_ffa_init() are completed. When this occurs, probing the TPM device is deferred. However, the deferred probe can happen after the IMA subsystem has already been initialized, since IMA initialization is performed during late_initcall, and deferred_probe_initcall() is performed at the same level. And the similar situation is reported on TPM devices attached on SPI bus[0]. To resolve this, introduce IMA_INIT_LATE_SYNC option to initialise IMA at late_inicall_sync so that IMA is initialized with the TPM device probed deferred. When this option is enabled, modules that access files in the initramfs through usermode helper calls such as request_module() during initcall must not be built-in. Otherwise, IMA may miss measuring those files [1]. Link: https://lore.kernel.org/all/aYXEepLhUouN5f99@earth.li/ [0] Link: https://lore.kernel.org/all/2b3782398cc17ce9d355490a0c42ebce9120a9ae.camel@linux.ibm.com/ [1] Suggested-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> [zohar@linux.ibm.com: Fixed Kconfig merge conflict] Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-08-04security: lsm: allow LSMs to register for late_initcall_sync initYeoreum Yun1-2/+11
There are situations where LSMs have dependencies that might mean they want to be initialised later in the boot process, to ensure those dependencies are available. In particular there are some TPM setups (Arm FF-A devices, SPI attached TPMs) required by IMA which are not guaranteed to be initialised for regular initcall_late. Add an initcall_late_sync option that can be used in these situations. Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com> Cc: Paul Moore <paul@paul-moore.com> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-08-04selinux: check level category sets once at load timeStephen Smalley2-17/+30
As reported by Jiri Vozar, commit 7edea6e8c8e8 ("selinux: beef up isvalid checks") introduces a new loop in mls_level_isvalid() that causes ~89-94% throughput regression in System V IPC message queue operations (msgsnd/msgrcv). Move the expensive part of the ebitmap checking to policy load time instead as the reporter suggested. Link: https://lore.kernel.org/selinux/CAMgFczCi2Z011dNf84Amc0Q-qnTt0+VUjWY+Y7zPyXdaH35Jvw@mail.gmail.com/ Fixes: 7edea6e8c8e8 ("selinux: beef up isvalid checks") Reported-by: Jiri Vozar <jvozar@redhat.com> Suggested-by: Jiri Vozar <jvozar@redhat.com> Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>