POSIX capabilities are pieces of root privilege, for instance CAP_SYS_NICE to set priority on other tasks and CAP_SYS_TIME to set system time. See http://www.kernel.org/pub/linux/libs/security/linux-privs/kernel-2.4/capfaq-0.2.txt for more information. A task's capabilities are set when it executes a new file, and when it explicitly changes them (see capset(2)). After exec, the task's new capabilities are a function of its previous capabilities and the file's capabilities: pI' = pI pP' = fP | (fI & pI) pE' = fE ? pP' : 0 Where pX is capability set X for process p before exec, pX' is capability set X for process P after exec and fX is file capability set X. The capability sets are I for inheritable, P for permitted, and E for effective. Note that fE is a boolean rather than a set. File capabilities are stored in extended attributes named 'security.capability.' Setting this xattr requires the CAP_SETFCAP capability when the capability security module is loaded, or CAP_SYS_ADMIN when it is not. The following tests are implemented here: inh_capped: check whether a process without CAP_SETPCAP is properly prohibited from raising bits in its inheritable set using setcap. verify_caps_exec: 1. check that privilege is needed to set file capabilities 2. check that pI', pP', and pE' are properly calculated upon exec. The Underlying kernel needs to be built with the following options for filecaps testing: CONFIG_SECURITY_CAPABILITIES=y