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- /* SPDX-License-Identifier: GPL-2.0-only */
- /**
- * DOC: erratum_2
- *
- * Erratum 2: Scoped signal handling
- * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- *
- * This fix addresses an issue where signal scoping was overly restrictive,
- * preventing sandboxed threads from signaling other threads within the same
- * process if they belonged to different domains. Because threads are not
- * security boundaries, user space might assume that all threads within the same
- * process can send signals between themselves (see :manpage:`nptl(7)` and
- * :manpage:`libpsx(3)`). Consistent with :manpage:`ptrace(2)` behavior, direct
- * interaction between threads of the same process should always be allowed.
- * This change ensures that any thread is allowed to send signals to any other
- * thread within the same process, regardless of their domain.
- *
- * Impact:
- *
- * This problem only manifests when the userspace process is itself using
- * :manpage:`libpsx(3)` or an equivalent mechanism to enforce a Landlock policy
- * on multiple already-running threads at once. Programs which enforce a
- * Landlock policy at startup time and only then become multithreaded are not
- * affected. Without this fix, signal scoping could break multi-threaded
- * applications that expect threads within the same process to freely signal
- * each other.
- */
- LANDLOCK_ERRATUM(2)
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