1 #ifndef _UAPI_LINUX_SECUREBITS_H 2 #define _UAPI_LINUX_SECUREBITS_H 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 /* _UAPI_LINUX_SECUREBITS_H */ 52