/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ #ifndef _LINUX_SECUREBITS_H #define _LINUX_SECUREBITS_H /* Each securesetting is implemented using two bits. One bit specifies whether the setting is on or off. The other bit specify whether the setting is locked or not. A setting which is locked cannot be changed from user-level. */ #define issecure_mask(X) (1 << (X)) #define SECUREBITS_DEFAULT 0x00000000 /* When set UID 0 has no special privileges. When unset, we support inheritance of root-permissions and suid-root executable under compatibility mode. We raise the effective and inheritable bitmasks *of the executable file* if the effective uid of the new process is 0. If the real uid is 0, we raise the effective (legacy) bit of the executable file. */ #define SECURE_NOROOT 0 #define SECURE_NOROOT_LOCKED 1 /* make bit-0 immutable */ #define SECBIT_NOROOT (issecure_mask(SECURE_NOROOT)) #define SECBIT_NOROOT_LOCKED (issecure_mask(SECURE_NOROOT_LOCKED)) /* When set, setuid to/from uid 0 does not trigger capability-"fixup". When unset, to provide compatiblility with old programs relying on set*uid to gain/lose privilege, transitions to/from uid 0 cause capabilities to be gained/lost. */ #define SECURE_NO_SETUID_FIXUP 2 #define SECURE_NO_SETUID_FIXUP_LOCKED 3 /* make bit-2 immutable */ #define SECBIT_NO_SETUID_FIXUP (issecure_mask(SECURE_NO_SETUID_FIXUP)) #define SECBIT_NO_SETUID_FIXUP_LOCKED \ (issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED)) /* When set, a process can retain its capabilities even after transitioning to a non-root user (the set-uid fixup suppressed by bit 2). Bit-4 is cleared when a process calls exec(); setting both bit 4 and 5 will create a barrier through exec that no exec()'d child can use this feature again. */ #define SECURE_KEEP_CAPS 4 #define SECURE_KEEP_CAPS_LOCKED 5 /* make bit-4 immutable */ #define SECBIT_KEEP_CAPS (issecure_mask(SECURE_KEEP_CAPS)) #define SECBIT_KEEP_CAPS_LOCKED (issecure_mask(SECURE_KEEP_CAPS_LOCKED)) /* When set, a process cannot add new capabilities to its ambient set. */ #define SECURE_NO_CAP_AMBIENT_RAISE 6 #define SECURE_NO_CAP_AMBIENT_RAISE_LOCKED 7 /* make bit-6 immutable */ #define SECBIT_NO_CAP_AMBIENT_RAISE (issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE)) #define SECBIT_NO_CAP_AMBIENT_RAISE_LOCKED \ (issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE_LOCKED)) #define SECURE_ALL_BITS (issecure_mask(SECURE_NOROOT) | \ issecure_mask(SECURE_NO_SETUID_FIXUP) | \ issecure_mask(SECURE_KEEP_CAPS) | \ issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE)) #define SECURE_ALL_LOCKS (SECURE_ALL_BITS << 1) #endif /* _LINUX_SECUREBITS_H */