iOS < 12.2 / macOS < 10.14.4 XNU - pidversion Increment During execve is Unsafe

Privileged IPC services in userspace often have to verify the security context of their client processes such as whether the client is sandboxed, has a specific entitlement, or is signed by some code signing authority. This, in turn, requires a way to identify a client process. If PIDs are used f...