System V shared memory is a Unix interprocess communication mechanism. The kernel creates a memory segment that multiple processes can attach to, allowing them to exchange data without repeatedly copying it through files or pipes. The kernel tracks each segment and its attachments, including when it may be detached or removed.
This bookkeeping is security-sensitive: incorrect counters or lifecycle handling can cause a segment to be freed or reused while a process still relies on it. In a kernel exploit, an attacker with local code execution may target such flaws to trigger memory corruption or help build a privilege-escalation chain. Defenders should apply relevant kernel updates and, where shared memory is unnecessary, limit its use through system configuration and access controls.