differ from the effective IDs by calling setfsuid (2) and setfsgid (2). • Supplementary group ... process's effective user (group) ID. setfsuid (2) ( setfsgid (2)) Modify the proce…UIDs ( setuid (2), setreuid (2), setresuid (2), setfsuid (2)); • forge UID when passing socket credentials ... changed from 0 to nonzero (see setfsuid (2)), then the following capa…changed by the system call setfsuid (2). (Here "fsuid" stands for something like "filesystem user ... obsolete now. Nobody should use setfsuid (2).) Similarly, Linux uses the fsgid…relevant system calls include setuid (2), setfsuid (2), setreuid (2), and setresuid (2). For group