1#ifndef _LINUX_SECUREBITS_H 2#define _LINUX_SECUREBITS_H 1 3 4/* Each securesetting is implemented using two bits. One bit specifies 5 whether the setting is on or off. The other bit specify whether the 6 setting is locked or not. A setting which is locked cannot be 7 changed from user-level. */ 8#define issecure_mask(X) (1 << (X)) 9 10#define SECUREBITS_DEFAULT 0x00000000 11 12/* When set UID 0 has no special privileges. When unset, we support 13 inheritance of root-permissions and suid-root executable under 14 compatibility mode. We raise the effective and inheritable bitmasks 15 *of the executable file* if the effective uid of the new process is 16 0. If the real uid is 0, we raise the effective (legacy) bit of the 17 executable file. */ 18#define SECURE_NOROOT 0 19#define SECURE_NOROOT_LOCKED 1 /* make bit-0 immutable */ 20 21#define SECBIT_NOROOT (issecure_mask(SECURE_NOROOT)) 22#define SECBIT_NOROOT_LOCKED (issecure_mask(SECURE_NOROOT_LOCKED)) 23 24/* When set, setuid to/from uid 0 does not trigger capability-"fixup". 25 When unset, to provide compatiblility with old programs relying on 26 set*uid to gain/lose privilege, transitions to/from uid 0 cause 27 capabilities to be gained/lost. */ 28#define SECURE_NO_SETUID_FIXUP 2 29#define SECURE_NO_SETUID_FIXUP_LOCKED 3 /* make bit-2 immutable */ 30 31#define SECBIT_NO_SETUID_FIXUP (issecure_mask(SECURE_NO_SETUID_FIXUP)) 32#define SECBIT_NO_SETUID_FIXUP_LOCKED \ 33 (issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED)) 34 35/* When set, a process can retain its capabilities even after 36 transitioning to a non-root user (the set-uid fixup suppressed by 37 bit 2). Bit-4 is cleared when a process calls exec(); setting both 38 bit 4 and 5 will create a barrier through exec that no exec()'d 39 child can use this feature again. */ 40#define SECURE_KEEP_CAPS 4 41#define SECURE_KEEP_CAPS_LOCKED 5 /* make bit-4 immutable */ 42 43#define SECBIT_KEEP_CAPS (issecure_mask(SECURE_KEEP_CAPS)) 44#define SECBIT_KEEP_CAPS_LOCKED (issecure_mask(SECURE_KEEP_CAPS_LOCKED)) 45 46#define SECURE_ALL_BITS (issecure_mask(SECURE_NOROOT) | \ 47 issecure_mask(SECURE_NO_SETUID_FIXUP) | \ 48 issecure_mask(SECURE_KEEP_CAPS)) 49#define SECURE_ALL_LOCKS (SECURE_ALL_BITS << 1) 50 51#endif /* !_LINUX_SECUREBITS_H */ 52