Memfd

Memfd Seals Turn Shared Memory Into Monotonic File Policy

Memfd Seals Turn Shared Memory Into Monotonic File Policy A process prepares a binary object in memory, passes its file descriptor to another process, and expects the bytes to remain stable after validation. Ordinary shared memory does not provide that property by itself: another holder of writable authority can change the object after a check, resize it, or keep a writable mapping alive. Linux file seals provide a narrower contract. They remove selected mutation operations from a sealable file, and successfully added seals cannot later be removed.