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2025-03-26landlock: Add audit documentationMickaël Salaün
Because audit is dedicated to the system administrator, create a new entry in Documentation/admin-guide/LSM . Extend other Landlock documentation's pages with this new one. Extend UAPI with the new log flags. Extend the guiding principles with logs. Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20250320190717.2287696-29-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26selftests/landlock: Add audit tests for networkMickaël Salaün
Test all network blockers: - net.bind_tcp - net.connect_tcp Test coverage for security/landlock is 94.0% of 1525 lines according to gcc/gcov-14. Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20250320190717.2287696-28-mic@digikod.net [mic: Update test coverage] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26selftests/landlock: Add audit tests for filesystemMickaël Salaün
Test all filesystem blockers, including events with several records, and record with several blockers: - fs.execute - fs.write_file - fs.read_file - fs_read_dir - fs.remove_dir - fs.remove_file - fs.make_char - fs.make_dir - fs.make_reg - fs.make_sock - fs.make_fifo - fs.make_block - fs.make_sym - fs.refer - fs.truncate - fs.ioctl_dev - fs.change_topology Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20250320190717.2287696-27-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26selftests/landlock: Add audit tests for abstract UNIX socket scopingMickaël Salaün
Add a new scoped_audit.connect_to_child test to check the abstract UNIX socket blocker. Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20250320190717.2287696-26-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26selftests/landlock: Add audit tests for ptraceMickaël Salaün
Add tests for all ptrace actions checking "blockers=ptrace" records. This also improves PTRACE_TRACEME and PTRACE_ATTACH tests by making sure that the restrictions comes from Landlock, and with the expected process. These extended tests are like enhanced errno checks that make sure Landlock enforcement is consistent. Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20250320190717.2287696-25-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26selftests/landlock: Test audit with restrict flagsMickaël Salaün
Add audit_exec tests to filter Landlock denials according to cross-execution or muted subdomains. Add a wait-pipe-sandbox.c test program to sandbox itself and send a (denied) signals to its parent. Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20250320190717.2287696-24-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26selftests/landlock: Add tests for audit flags and domain IDsMickaël Salaün
Add audit_test.c to check with and without LANDLOCK_RESTRICT_SELF_* flags against the two Landlock audit record types: AUDIT_LANDLOCK_ACCESS and AUDIT_LANDLOCK_DOMAIN. Check consistency of domain IDs per layer in AUDIT_LANDLOCK_ACCESS and AUDIT_LANDLOCK_DOMAIN messages: denied access, domain allocation, and domain deallocation. These tests use signal scoping to make it simple. They are not in the scoped_signal_test.c file but in the new dedicated audit_test.c file. Tests are run with audit filters to ensure the audit records come from the test program. Moreover, because there can only be one audit process, tests would failed if run in parallel. Because of audit limitations, tests can only be run in the initial namespace. The audit test helpers were inspired by libaudit and tools/testing/selftests/net/netfilter/audit_logread.c Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Phil Sutter <phil@nwl.cc> Link: https://lore.kernel.org/r/20250320190717.2287696-23-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26selftests/landlock: Extend tests for landlock_restrict_self(2)'s flagsMickaël Salaün
Add the base_test's restrict_self_fd_flags tests to align with previous restrict_self_fd tests but with the new LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF flag. Add the restrict_self_flags tests to check that LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF, LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON, and LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF are valid but not the next bit. Some checks are similar to restrict_self_checks_ordering's ones. Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20250320190717.2287696-22-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26selftests/landlock: Add test for invalid ruleset file descriptorMickaël Salaün
To align with fs_test's layout1.inval and layout0.proc_nsfs which test EBADFD for landlock_add_rule(2), create a new base_test's restrict_self_fd which test EBADFD for landlock_restrict_self(2). Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20250320190717.2287696-21-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26samples/landlock: Enable users to log sandbox denialsMickaël Salaün
By default, denials from within the sandbox are not logged. Indeed, the sandboxer's security policy might not be fitted to the set of sandboxed processes that could be spawned (e.g. from a shell). For test purpose, parse the LL_FORCE_LOG environment variable to log every sandbox denials, including after launching the initial sandboxed program thanks to LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON. Cc: Günther Noack <gnoack@google.com> Link: https://lore.kernel.org/r/20250320190717.2287696-20-mic@digikod.net [mic: Remove inappropriate hunk] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Add LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFFMickaël Salaün
Add LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF for the case of sandboxer tools, init systems, or runtime containers launching programs sandboxing themselves in an inconsistent way. Setting this flag should only depends on runtime configuration (i.e. not hardcoded). We don't create a new ruleset's option because this should not be part of the security policy: only the task that enforces the policy (not the one that create it) knows if itself or its children may request denied actions. This is the first and only flag that can be set without actually restricting the caller (i.e. without providing a ruleset). Extend struct landlock_cred_security with a u8 log_subdomains_off. struct landlock_file_security is still 16 bytes. Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Closes: https://github.com/landlock-lsm/linux/issues/3 Link: https://lore.kernel.org/r/20250320190717.2287696-19-mic@digikod.net [mic: Fix comment] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Add LANDLOCK_RESTRICT_SELF_LOG_*_EXEC_* flagsMickaël Salaün
Most of the time we want to log denied access because they should not happen and such information helps diagnose issues. However, when sandboxing processes that we know will try to access denied resources (e.g. unknown, bogus, or malicious binary), we might want to not log related access requests that might fill up logs. By default, denied requests are logged until the task call execve(2). If the LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF flag is set, denied requests will not be logged for the same executed file. If the LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON flag is set, denied requests from after an execve(2) call will be logged. The rationale is that a program should know its own behavior, but not necessarily the behavior of other programs. Because LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF is set for a specific Landlock domain, it makes it possible to selectively mask some access requests that would be logged by a parent domain, which might be handy for unprivileged processes to limit logs. However, system administrators should still use the audit filtering mechanism. There is intentionally no audit nor sysctl configuration to re-enable these logs. This is delegated to the user space program. Increment the Landlock ABI version to reflect this interface change. Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20250320190717.2287696-18-mic@digikod.net [mic: Rename variables and fix __maybe_unused] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Log scoped denialsMickaël Salaün
Add audit support for unix_stream_connect, unix_may_send, task_kill, and file_send_sigiotask hooks. The related blockers are: - scope.abstract_unix_socket - scope.signal Audit event sample for abstract unix socket: type=LANDLOCK_DENY msg=audit(1729738800.268:30): domain=195ba459b blockers=scope.abstract_unix_socket path=00666F6F Audit event sample for signal: type=LANDLOCK_DENY msg=audit(1729738800.291:31): domain=195ba459b blockers=scope.signal opid=1 ocomm="systemd" Refactor and simplify error handling in LSM hooks. Extend struct landlock_file_security with fown_layer and use it to log the blocking domain. The struct aligned size is still 16 bytes. Cc: Günther Noack <gnoack@google.com> Cc: Tahera Fahimi <fahimitahera@gmail.com> Link: https://lore.kernel.org/r/20250320190717.2287696-17-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Log TCP bind and connect denialsMickaël Salaün
Add audit support to socket_bind and socket_connect hooks. The related blockers are: - net.bind_tcp - net.connect_tcp Audit event sample: type=LANDLOCK_DENY msg=audit(1729738800.349:44): domain=195ba459b blockers=net.connect_tcp daddr=127.0.0.1 dest=80 Cc: Günther Noack <gnoack@google.com> Cc: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> Cc: Mikhail Ivanov <ivanov.mikhail1@huawei-partners.com> Link: https://lore.kernel.org/r/20250320190717.2287696-16-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Log truncate and IOCTL denialsMickaël Salaün
Add audit support to the file_truncate and file_ioctl hooks. Add a deny_masks_t type and related helpers to store the domain's layer level per optional access rights (i.e. LANDLOCK_ACCESS_FS_TRUNCATE and LANDLOCK_ACCESS_FS_IOCTL_DEV) when opening a file, which cannot be inferred later. In practice, the landlock_file_security aligned blob size is still 16 bytes because this new one-byte deny_masks field follows the existing two-bytes allowed_access field and precede the packed fown_subject. Implementing deny_masks_t with a bitfield instead of a struct enables a generic implementation to store and extract layer levels. Add KUnit tests to check the identification of a layer level from a deny_masks_t, and the computation of a deny_masks_t from an access right with its layer level or a layer_mask_t array. Audit event sample: type=LANDLOCK_DENY msg=audit(1729738800.349:44): domain=195ba459b blockers=fs.ioctl_dev path="/dev/tty" dev="devtmpfs" ino=9 ioctlcmd=0x5401 Cc: Günther Noack <gnoack@google.com> Link: https://lore.kernel.org/r/20250320190717.2287696-15-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Factor out IOCTL hooksMickaël Salaün
Compat and non-compat IOCTL hooks are almost the same, except to compare the IOCTL command. Factor out these two IOCTL hooks to highlight the difference and minimize audit changes (see next commit). Cc: Günther Noack <gnoack@google.com> Link: https://lore.kernel.org/r/20250320190717.2287696-14-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Log file-related denialsMickaël Salaün
Add audit support for path_mkdir, path_mknod, path_symlink, path_unlink, path_rmdir, path_truncate, path_link, path_rename, and file_open hooks. The dedicated blockers are: - fs.execute - fs.write_file - fs.read_file - fs.read_dir - fs.remove_dir - fs.remove_file - fs.make_char - fs.make_dir - fs.make_reg - fs.make_sock - fs.make_fifo - fs.make_block - fs.make_sym - fs.refer - fs.truncate - fs.ioctl_dev Audit event sample for a denied link action: type=LANDLOCK_DENY msg=audit(1729738800.349:44): domain=195ba459b blockers=fs.refer path="/usr/bin" dev="vda2" ino=351 type=LANDLOCK_DENY msg=audit(1729738800.349:44): domain=195ba459b blockers=fs.make_reg,fs.refer path="/usr/local" dev="vda2" ino=365 We could pack blocker names (e.g. "fs:make_reg,refer") but that would increase complexity for the kernel and log parsers. Moreover, this could not handle blockers of different classes (e.g. fs and net). Make it simple and flexible instead. Add KUnit tests to check the identification from a layer_mask_t array of the first layer level denying such request. Cc: Günther Noack <gnoack@google.com> Depends-on: 058518c20920 ("landlock: Align partial refer access checks with final ones") Depends-on: d617f0d72d80 ("landlock: Optimize file path walks and prepare for audit support") Link: https://lore.kernel.org/r/20250320190717.2287696-13-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Log mount-related denialsMickaël Salaün
Add audit support for sb_mount, move_mount, sb_umount, sb_remount, and sb_pivot_root hooks. The new related blocker is "fs.change_topology". Audit event sample: type=LANDLOCK_DENY msg=audit(1729738800.349:44): domain=195ba459b blockers=fs.change_topology name="/" dev="tmpfs" ino=1 Remove landlock_get_applicable_domain() and get_current_fs_domain() which are now fully replaced with landlock_get_applicable_subject(). Cc: Günther Noack <gnoack@google.com> Link: https://lore.kernel.org/r/20250320190717.2287696-12-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Add AUDIT_LANDLOCK_DOMAIN and log domain statusMickaël Salaün
Asynchronously log domain information when it first denies an access. This minimize the amount of generated logs, which makes it possible to always log denials for the current execution since they should not happen. These records are identified with the new AUDIT_LANDLOCK_DOMAIN type. The AUDIT_LANDLOCK_DOMAIN message contains: - the "domain" ID which is described; - the "status" which can either be "allocated" or "deallocated"; - the "mode" which is for now only "enforcing"; - for the "allocated" status, a minimal set of properties to easily identify the task that loaded the domain's policy with landlock_restrict_self(2): "pid", "uid", executable path ("exe"), and command line ("comm"); - for the "deallocated" state, the number of "denials" accounted to this domain, which is at least 1. This requires each domain to save these task properties at creation time in the new struct landlock_details. A reference to the PID is kept for the lifetime of the domain to avoid race conditions when investigating the related task. The executable path is resolved and stored to not keep a reference to the filesystem and block related actions. All these metadata are stored for the lifetime of the related domain and should then be minimal. The required memory is not accounted to the task calling landlock_restrict_self(2) contrary to most other Landlock allocations (see related comment). The AUDIT_LANDLOCK_DOMAIN record follows the first AUDIT_LANDLOCK_ACCESS record for the same domain, which is always followed by AUDIT_SYSCALL and AUDIT_PROCTITLE. This is in line with the audit logic to first record the cause of an event, and then add context with other types of record. Audit event sample for a first denial: type=LANDLOCK_ACCESS msg=audit(1732186800.349:44): domain=195ba459b blockers=ptrace opid=1 ocomm="systemd" type=LANDLOCK_DOMAIN msg=audit(1732186800.349:44): domain=195ba459b status=allocated mode=enforcing pid=300 uid=0 exe="/root/sandboxer" comm="sandboxer" type=SYSCALL msg=audit(1732186800.349:44): arch=c000003e syscall=101 success=no [...] pid=300 auid=0 Audit event sample for a following denial: type=LANDLOCK_ACCESS msg=audit(1732186800.372:45): domain=195ba459b blockers=ptrace opid=1 ocomm="systemd" type=SYSCALL msg=audit(1732186800.372:45): arch=c000003e syscall=101 success=no [...] pid=300 auid=0 Log domain deletion with the "deallocated" state when a domain was previously logged. This makes it possible for log parsers to free potential resources when a domain ID will never show again. The number of denied access requests is useful to easily check how many access requests a domain blocked and potentially if some of them are missing in logs because of audit rate limiting, audit rules, or Landlock log configuration flags (see following commit). Audit event sample for a deletion of a domain that denied something: type=LANDLOCK_DOMAIN msg=audit(1732186800.393:46): domain=195ba459b status=deallocated denials=2 Cc: Günther Noack <gnoack@google.com> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20250320190717.2287696-11-mic@digikod.net [mic: Update comment and GFP flag for landlock_log_drop_domain()] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Add AUDIT_LANDLOCK_ACCESS and log ptrace denialsMickaël Salaün
Add a new AUDIT_LANDLOCK_ACCESS record type dedicated to an access request denied by a Landlock domain. AUDIT_LANDLOCK_ACCESS indicates that something unexpected happened. For now, only denied access are logged, which means that any AUDIT_LANDLOCK_ACCESS record is always followed by a SYSCALL record with "success=no". However, log parsers should check this syscall property because this is the only sign that a request was denied. Indeed, we could have "success=yes" if Landlock would support a "permissive" mode. We could also add a new field to AUDIT_LANDLOCK_DOMAIN for this mode (see following commit). By default, the only logged access requests are those coming from the same executed program that enforced the Landlock restriction on itself. In other words, no audit record are created for a task after it called execve(2). This is required to avoid log spam because programs may only be aware of their own restrictions, but not the inherited ones. Following commits will allow to conditionally generate AUDIT_LANDLOCK_ACCESS records according to dedicated landlock_restrict_self(2)'s flags. The AUDIT_LANDLOCK_ACCESS message contains: - the "domain" ID restricting the action on an object, - the "blockers" that are missing to allow the requested access, - a set of fields identifying the related object (e.g. task identified with "opid" and "ocomm"). The blockers are implicit restrictions (e.g. ptrace), or explicit access rights (e.g. filesystem), or explicit scopes (e.g. signal). This field contains a list of at least one element, each separated with a comma. The initial blocker is "ptrace", which describe all implicit Landlock restrictions related to ptrace (e.g. deny tracing of tasks outside a sandbox). Add audit support to ptrace_access_check and ptrace_traceme hooks. For the ptrace_access_check case, we log the current/parent domain and the child task. For the ptrace_traceme case, we log the parent domain and the current/child task. Indeed, the requester and the target are the current task, but the action would be performed by the parent task. Audit event sample: type=LANDLOCK_ACCESS msg=audit(1729738800.349:44): domain=195ba459b blockers=ptrace opid=1 ocomm="systemd" type=SYSCALL msg=audit(1729738800.349:44): arch=c000003e syscall=101 success=no [...] pid=300 auid=0 A following commit adds user documentation. Add KUnit tests to check reading of domain ID relative to layer level. The quick return for non-landlocked tasks is moved from task_ptrace() to each LSM hooks. It is not useful to inline the audit_enabled check because other computation are performed by landlock_log_denial(). Use scoped guards for RCU read-side critical sections. Cc: Günther Noack <gnoack@google.com> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20250320190717.2287696-10-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Identify domain execution crossingMickaël Salaün
Extend struct landlock_cred_security with a domain_exec bitmask to identify which Landlock domain were created by the current task's bprm. The whole bitmask is reset on each execve(2) call. Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20250320190717.2287696-9-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Prepare to use credential instead of domain for fownerMickaël Salaün
This cosmetic change is needed for audit support, specifically to be able to filter according to cross-execution boundaries. struct landlock_file_security's size stay the same for now but it will increase with struct landlock_cred_security's size. Only save Landlock domain in hook_file_set_fowner() if the current domain has LANDLOCK_SCOPE_SIGNAL, which was previously done for each hook_file_send_sigiotask() calls. This should improve a bit performance. Replace hardcoded LANDLOCK_SCOPE_SIGNAL with the signal_scope.scope variable. Use scoped guards for RCU read-side critical sections. Cc: Günther Noack <gnoack@google.com> Link: https://lore.kernel.org/r/20250320190717.2287696-8-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Prepare to use credential instead of domain for scopeMickaël Salaün
This cosmetic change that is needed for audit support, specifically to be able to filter according to cross-execution boundaries. Replace hardcoded LANDLOCK_SCOPE_SIGNAL with the signal_scope.scope variable. Use scoped guards for RCU read-side critical sections. Cc: Günther Noack <gnoack@google.com> Link: https://lore.kernel.org/r/20250320190717.2287696-7-mic@digikod.net [mic: Update headers] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Prepare to use credential instead of domain for networkMickaël Salaün
This cosmetic change that is needed for audit support, specifically to be able to filter according to cross-execution boundaries. Optimize current_check_access_socket() to only handle the access request. Remove explicit domain->num_layers check which is now part of the landlock_get_applicable_subject() call. Cc: Günther Noack <gnoack@google.com> Link: https://lore.kernel.org/r/20250320190717.2287696-6-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Prepare to use credential instead of domain for filesystemMickaël Salaün
This cosmetic change is needed for audit support, specifically to be able to filter according to cross-execution boundaries. Add landlock_get_applicable_subject(), mainly a copy of landlock_get_applicable_domain(), which will fully replace it in a following commit. Optimize current_check_access_path() to only handle the access request. Partially replace get_current_fs_domain() with explicit calls to landlock_get_applicable_subject(). The remaining ones will follow with more changes. Remove explicit domain->num_layers check which is now part of the landlock_get_applicable_subject() call. Cc: Günther Noack <gnoack@google.com> Link: https://lore.kernel.org/r/20250320190717.2287696-5-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Move domain hierarchy managementMickaël Salaün
Create a new domain.h file containing the struct landlock_hierarchy definition and helpers. This type will grow with audit support. This also prepares for a new domain type. Cc: Günther Noack <gnoack@google.com> Link: https://lore.kernel.org/r/20250320190717.2287696-4-mic@digikod.net Reviewed-by: Günther Noack <gnoack3000@gmail.com> Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Add unique ID generatorMickaël Salaün
Landlock IDs can be generated to uniquely identify Landlock objects. For now, only Landlock domains get an ID at creation time. These IDs map to immutable domain hierarchies. Landlock IDs have important properties: - They are unique during the lifetime of the running system thanks to the 64-bit values: at worse, 2^60 - 2*2^32 useful IDs. - They are always greater than 2^32 and must then be stored in 64-bit integer types. - The initial ID (at boot time) is randomly picked between 2^32 and 2^33, which limits collisions in logs across different boots. - IDs are sequential, which enables users to order them. - IDs may not be consecutive but increase with a random 2^4 step, which limits side channels. Such IDs can be exposed to unprivileged processes, even if it is not the case with this audit patch series. The domain IDs will be useful for user space to identify sandboxes and get their properties. These Landlock IDs are more secure that other absolute kernel IDs such as pipe's inodes which rely on a shared global counter. For checkpoint/restore features (i.e. CRIU), we could easily implement a privileged interface (e.g. sysfs) to set the next ID counter. IDR/IDA are not used because we only need a bijection from Landlock objects to Landlock IDs, and we must not recycle IDs. This enables us to identify all Landlock objects during the lifetime of the system (e.g. in logs), but not to access an object from an ID nor know if an ID is assigned. Using a counter is simpler, it scales (i.e. avoids growing memory footprint), and it does not require locking. We'll use proper file descriptors (with IDs used as inode numbers) to access Landlock objects. Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20250320190717.2287696-3-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26lsm: Add audit_log_lsm_data() helperMickaël Salaün
Extract code from dump_common_audit_data() into the audit_log_lsm_data() helper. This helps reuse common LSM audit data while not abusing AUDIT_AVC records because of the common_lsm_audit() helper. Depends-on: 7ccbe076d987 ("lsm: Only build lsm_audit.c if CONFIG_SECURITY and CONFIG_AUDIT are set") Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: James Morris <jmorris@namei.org> Cc: Serge E. Hallyn <serge@hallyn.com> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20250320190717.2287696-2-mic@digikod.net Reviewed-by: Günther Noack <gnoack3000@gmail.com> Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26selftests/landlock: Add a new test for setuid()Mickaël Salaün
The new signal_scoping_thread_setuid tests check that the libc's setuid() function works as expected even when a thread is sandboxed with scoped signal restrictions. Before the signal scoping fix, this test would have failed with the setuid() call: [pid 65] getpid() = 65 [pid 65] tgkill(65, 66, SIGRT_1) = -1 EPERM (Operation not permitted) [pid 65] futex(0x40a66cdc, FUTEX_WAKE_PRIVATE, 1) = 0 [pid 65] setuid(1001) = 0 After the fix, tgkill(2) is successfully leveraged to synchronize credentials update across threads: [pid 65] getpid() = 65 [pid 65] tgkill(65, 66, SIGRT_1) = 0 [pid 66] <... read resumed>0x40a65eb7, 1) = ? ERESTARTSYS (To be restarted if SA_RESTART is set) [pid 66] --- SIGRT_1 {si_signo=SIGRT_1, si_code=SI_TKILL, si_pid=65, si_uid=1000} --- [pid 66] getpid() = 65 [pid 66] setuid(1001) = 0 [pid 66] futex(0x40a66cdc, FUTEX_WAKE_PRIVATE, 1) = 0 [pid 66] rt_sigreturn({mask=[]}) = 0 [pid 66] read(3, <unfinished ...> [pid 65] setuid(1001) = 0 Test coverage for security/landlock is 92.9% of 1137 lines according to gcc/gcov-14. Fixes: c8994965013e ("selftests/landlock: Test signal scoping for threads") Cc: Günther Noack <gnoack@google.com> Cc: Tahera Fahimi <fahimitahera@gmail.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250318161443.279194-8-mic@digikod.net [mic: Update test coverage] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26selftests/landlock: Split signal_scoping_threads testsMickaël Salaün
Split signal_scoping_threads tests into signal_scoping_thread_before and signal_scoping_thread_after. Use local variables for thread synchronization. Fix exported function. Replace some asserts with expects. Fixes: c8994965013e ("selftests/landlock: Test signal scoping for threads") Cc: Günther Noack <gnoack@google.com> Cc: Tahera Fahimi <fahimitahera@gmail.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250318161443.279194-7-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26landlock: Always allow signals between threads of the same processMickaël Salaün
Because Linux credentials are managed per thread, user space relies on some hack to synchronize credential update across threads from the same process. This is required by the Native POSIX Threads Library and implemented by set*id(2) wrappers and libcap(3) to use tgkill(2) to synchronize threads. See nptl(7) and libpsx(3). Furthermore, some runtimes like Go do not enable developers to have control over threads [1]. To avoid potential issues, and because threads are not security boundaries, let's relax the Landlock (optional) signal scoping to always allow signals sent between threads of the same process. This exception is similar to the __ptrace_may_access() one. hook_file_set_fowner() now checks if the target task is part of the same process as the caller. If this is the case, then the related signal triggered by the socket will always be allowed. Scoping of abstract UNIX sockets is not changed because kernel objects (e.g. sockets) should be tied to their creator's domain at creation time. Note that creating one Landlock domain per thread puts each of these threads (and their future children) in their own scope, which is probably not what users expect, especially in Go where we do not control threads. However, being able to drop permissions on all threads should not be restricted by signal scoping. We are working on a way to make it possible to atomically restrict all threads of a process with the same domain [2]. Add erratum for signal scoping. Closes: https://github.com/landlock-lsm/go-landlock/issues/36 Fixes: 54a6e6bbf3be ("landlock: Add signal scoping") Fixes: c8994965013e ("selftests/landlock: Test signal scoping for threads") Depends-on: 26f204380a3c ("fs: Fix file_set_fowner LSM hook inconsistencies") Link: https://pkg.go.dev/kernel.org/pub/linux/libs/security/libcap/psx [1] Link: https://github.com/landlock-lsm/linux/issues/2 [2] Cc: Günther Noack <gnoack@google.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Serge Hallyn <serge@hallyn.com> Cc: Tahera Fahimi <fahimitahera@gmail.com> Cc: stable@vger.kernel.org Acked-by: Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/r/20250318161443.279194-6-mic@digikod.net [mic: Add extra pointer check and RCU guard, and ease backport] Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26Merge branch 'for-6.15/wacom' into for-linusJiri Kosina
- removal of WACOM_PKGLEN_MAX limit in Wacom driver (Jason Gerecke)
2025-03-26Merge branch 'for-6.15/usb-hidbp' into for-linusJiri Kosina
- fix for LED_KANA handling in hidbp (junan)
2025-03-26Merge branch 'for-6.15/steam' into for-linusJiri Kosina
- code cleanup (Vicki Pfau)
2025-03-26Merge branch 'for-6.15/sony' into for-linusJiri Kosina
- PlayStation 5 controllers support (Alex Henrie)
2025-03-26Merge branch 'for-6.15/plantronics' into for-linusJiri Kosina
- improved mute handling (Terry Junge)
2025-03-26Merge branch 'for-6.15/pidff' into for-linusJiri Kosina
From: Tomasz Pakuła <tomasz.pakula.oficjalny@gmail.com> This patch series is focused on improving the compatibility and usability of the hid-pidff force feedback driver. Last patch introduces a new, universal driver for PID devices that need some special handling like report fixups, remapping the button range, managing new pidff quirks and setting desirable fuzz/flat values. This work has been done in the span of the past months with the help of the great Linux simracing community, with a little input from sim flight fans from FFBeast. No changes interfere with compliant and currently working PID devices. "Generic" codepath was tested as well with Moza and Simxperience AccuForce v2. I'm not married to the name. It's what we used previously, but if "universal" is confusing (pidff is already the generic driver), we can come up with something better like "hid-quirky-pidff" :) With v8 and tiny finx in v9, all the outstanding issues were resolved, additional pidff issues were fixed and hid-pidff defines moved to a dedicated header file. This patch series could be considered done bar any comments and requests from input maintainers. I could save more then a dozen lines of code by changing simple if statements to only occupy on line instead of two in there's a need for that.
2025-03-26Merge branch 'for-6.15/logitech' into for-linusJiri Kosina
- conversion of hid-lg-g15 to standard multicolor LED API (Kate Hsuan)
2025-03-26Merge branch 'for-6.15/lenovo' into for-linusJiri Kosina
- code cleanups (Dan Carpenter, Vishnu Sankar)
2025-03-26Merge branch 'for-6.15/intel-thc' into for-linusJiri Kosina
- removal of deprecated PCI API calls (Philipp Stanner) - code cleanups (Even Xu)
2025-03-26Merge branch 'for-6.15/intel-ish' into for-linusJiri Kosina
- intel-ish Kbuild cleanup (Jiri Kosina)
2025-03-26Merge branch 'for-6.15/google' into for-linusJiri Kosina
- small include cleanup (Wolfram Sang)
2025-03-26Merge branch 'for-6.15/core' into for-linusJiri Kosina
- differentiate warning for reserved item tag from unknown item tag, in accordance to 6.2.2.4 from the HID specification 1.11 (Tatsuya S)
2025-03-26Merge branch 'for-6.15/bpf' into for-linusJiri Kosina
- a few hid-bpf device fixes from udev-hid-bpf; XP-Pen and Huion plus one from TUXEDO (Benjamin Tissoires)
2025-03-26Merge branch 'for-6.15/apple' into for-linusJiri Kosina
- support for Apple Touch Bars (Kerem Karabay, Aditya Garg)
2025-03-26Merge branch 'for-6.15/amd_sfh' into for-linusJiri Kosina
From: Mario Limonciello <mario.limonciello@amd.com> Some platforms include a human presence detection (HPD) sensor. When enabled and a user is detected a wake event will be emitted from the sensor fusion hub that software can react to. Example use cases are "wake from suspend on approach" or to "lock when leaving". This is currently enabled by default on supported systems, but users can't control it. This essentially means that wake on approach is enabled which is a really surprising behavior to users that don't expect it. Instead of defaulting to enabled add a sysfs knob that users can use to enable the feature if desirable and set it to disabled by default.
2025-03-26io_uring/net: use REQ_F_IMPORT_BUFFER for send_zcCaleb Sander Mateos
Instead of a bool field in struct io_sr_msg, use REQ_F_IMPORT_BUFFER to track whether io_send_zc() has already imported the buffer. This flag already serves a similar purpose for sendmsg_zc and {read,write}v_fixed. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Suggested-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/20250325143943.1226467-1-csander@purestorage.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-03-25Merge tag 'media/v6.15-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media Pull media updates from Mauro Carvalho Chehab: - platform: synopsys: hdmirx: Fix 64-bit division for 32-bit targets - vim2m: print device name after registering device - Synopsys DesignWare HDMI RX Driver and various fixes - cec/printk fixes and the removal of the vidioc_g/s_ctrl and vidioc_queryctrl callbacks - AVerMedia H789-C PCIe support and rc-core structs padding - Several camera sensor patches - uvcvideo improvements - visl: Fix ERANGE error when setting enum controls - codec fixes - V4L2 camera sensor patches mostly - chips-media: wave5: Fixes - Add SDM670 camera subsystem - Qualcomm iris video decoder driver - dt-bindings: update clocks for sc7280-camss - various fixes and enhancements * tag 'media/v6.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (264 commits) media: pci: mgb4: include linux/errno.h media: synopsys: hdmirx: Fix signedness bug in hdmirx_parse_dt() media: platform: synopsys: hdmirx: Fix 64-bit division for 32-bit targets media: vim2m: print device name after registering device media: vivid: Introduce VIDEO_VIVID_OSD media: vivid: Move all fb_info references into vivid-osd media: platform: synopsys: hdmirx: Optimize struct snps_hdmirx_dev media: platform: synopsys: hdmirx: Remove unused HDMI audio CODEC relics media: platform: synopsys: hdmirx: Remove duplicated header inclusion media: qcom: Clean up Kconfig dependencies media: dvb-frontends: tda10048: Make the range of z explicit. media: platform: stm32: Add check for clk_enable() media: xilinx-tpg: fix double put in xtpg_parse_of() media: siano: Fix error handling in smsdvb_module_init() media: c8sectpfe: Call of_node_put(i2c_bus) only once in c8sectpfe_probe() media: i2c: tda1997x: Call of_node_put(ep) only once in tda1997x_parse_dt() dt-bindings: media: mediatek,vcodec: Revise description dt-bindings: media: mediatek,jpeg: Relax IOMMU max item count media: v4l2-dv-timings: prevent possible overflow in v4l2_detect_gtf() media: rockchip: rga: fix rga offset lookup ...
2025-03-25Merge tag 'auxdisplay-v6.15-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/andy/linux-auxdisplay Pull auxdisplay updates from Andy Shevchenko: - Refactor a couple of APIs to reduce amount of calls to memory allocator - Miscellaneous small fixes and improvements * tag 'auxdisplay-v6.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/andy/linux-auxdisplay: auxdisplay: hd44780: Rename hd to hdc in hd44780_common_alloc() auxdisplay: hd44780: Call charlcd_alloc() from hd44780_common_alloc() auxdisplay: panel: Make use of hd44780_common_free() auxdisplay: hd44780: Make use of hd44780_common_free() auxdisplay: hd44780: Introduce hd44780_common_free() auxdisplay: lcd2s: Allocate memory for custom data in charlcd_alloc() auxdisplay: charlcd: Partially revert "Move hwidth and bwidth to struct hd44780_common" auxdisplay: panel: Fix an API misuse in panel.c auxdisplay: hd44780: Fix an API misuse in hd44780.c auxdisplay: MAX6959 should select BITREVERSE auxdisplay: seg-led-gpio: use gpiod_multi_set_value_cansleep
2025-03-25Merge tag 'chrome-platform-v6.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux Pull chrome platform updates from Tzung-Bi Shih: - Support ACPI match for Framework systems - Expose new sysfs for: - PD mux status for each EC-managed Type-C port - EC feature of AP mode entry - Setting USB mode of EC Type-C * tag 'chrome-platform-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux: platform/chrome: cros_ec_typec: Add support for setting USB mode via sysfs platform/chrome: cros_ec_sysfs: Expose AP_MODE_ENTRY feature state platform/chrome: cros_ec_sysfs: Expose PD mux status platform/chrome: cros_ec_lpc: Match on Framework ACPI device MAINTAINERS: Update maintainers for ChromeOS USBC related drivers