alistair23-linux/include/uapi/linux/securebits.h
Andy Lutomirski 746bf6d642 capabilities: add a securebit to disable PR_CAP_AMBIENT_RAISE
Per Andrew Morgan's request, add a securebit to allow admins to disable
PR_CAP_AMBIENT_RAISE.  This securebit will prevent processes from adding
capabilities to their ambient set.

For simplicity, this disables PR_CAP_AMBIENT_RAISE entirely rather than
just disabling setting previously cleared bits.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Andrew G. Morgan <morgan@kernel.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Aaron Jones <aaronmdjones@gmail.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Andrew G. Morgan <morgan@kernel.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Austin S Hemmelgarn <ahferroin7@gmail.com>
Cc: Markku Savela <msa@moth.iki.fi>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: James Morris <james.l.morris@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04 16:54:41 -07:00

61 lines
2.6 KiB
C

#ifndef _UAPI_LINUX_SECUREBITS_H
#define _UAPI_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 /* _UAPI_LINUX_SECUREBITS_H */