diff options
Diffstat (limited to 'include/linux/securebits.h')
| -rw-r--r-- | include/linux/securebits.h | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/include/linux/securebits.h b/include/linux/securebits.h new file mode 100644 index 00000000000..33406174cbe --- /dev/null +++ b/include/linux/securebits.h @@ -0,0 +1,54 @@ +#ifndef _LINUX_SECUREBITS_H +#define _LINUX_SECUREBITS_H 1 + +/* 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)) +#ifdef __KERNEL__ +#define issecure(X) (issecure_mask(X) & current_cred_xxx(securebits)) +#endif + +#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)) + +#define SECURE_ALL_BITS (issecure_mask(SECURE_NOROOT) | \ + issecure_mask(SECURE_NO_SETUID_FIXUP) | \ + issecure_mask(SECURE_KEEP_CAPS)) +#define SECURE_ALL_LOCKS (SECURE_ALL_BITS << 1) + +#endif /* !_LINUX_SECUREBITS_H */ |