xref: /linux-6.15/include/uapi/linux/securebits.h (revision 607ca46e)
1*607ca46eSDavid Howells #ifndef _UAPI_LINUX_SECUREBITS_H
2*607ca46eSDavid Howells #define _UAPI_LINUX_SECUREBITS_H
3*607ca46eSDavid Howells 
4*607ca46eSDavid Howells /* Each securesetting is implemented using two bits. One bit specifies
5*607ca46eSDavid Howells    whether the setting is on or off. The other bit specify whether the
6*607ca46eSDavid Howells    setting is locked or not. A setting which is locked cannot be
7*607ca46eSDavid Howells    changed from user-level. */
8*607ca46eSDavid Howells #define issecure_mask(X)	(1 << (X))
9*607ca46eSDavid Howells 
10*607ca46eSDavid Howells #define SECUREBITS_DEFAULT 0x00000000
11*607ca46eSDavid Howells 
12*607ca46eSDavid Howells /* When set UID 0 has no special privileges. When unset, we support
13*607ca46eSDavid Howells    inheritance of root-permissions and suid-root executable under
14*607ca46eSDavid Howells    compatibility mode. We raise the effective and inheritable bitmasks
15*607ca46eSDavid Howells    *of the executable file* if the effective uid of the new process is
16*607ca46eSDavid Howells    0. If the real uid is 0, we raise the effective (legacy) bit of the
17*607ca46eSDavid Howells    executable file. */
18*607ca46eSDavid Howells #define SECURE_NOROOT			0
19*607ca46eSDavid Howells #define SECURE_NOROOT_LOCKED		1  /* make bit-0 immutable */
20*607ca46eSDavid Howells 
21*607ca46eSDavid Howells #define SECBIT_NOROOT		(issecure_mask(SECURE_NOROOT))
22*607ca46eSDavid Howells #define SECBIT_NOROOT_LOCKED	(issecure_mask(SECURE_NOROOT_LOCKED))
23*607ca46eSDavid Howells 
24*607ca46eSDavid Howells /* When set, setuid to/from uid 0 does not trigger capability-"fixup".
25*607ca46eSDavid Howells    When unset, to provide compatiblility with old programs relying on
26*607ca46eSDavid Howells    set*uid to gain/lose privilege, transitions to/from uid 0 cause
27*607ca46eSDavid Howells    capabilities to be gained/lost. */
28*607ca46eSDavid Howells #define SECURE_NO_SETUID_FIXUP		2
29*607ca46eSDavid Howells #define SECURE_NO_SETUID_FIXUP_LOCKED	3  /* make bit-2 immutable */
30*607ca46eSDavid Howells 
31*607ca46eSDavid Howells #define SECBIT_NO_SETUID_FIXUP	(issecure_mask(SECURE_NO_SETUID_FIXUP))
32*607ca46eSDavid Howells #define SECBIT_NO_SETUID_FIXUP_LOCKED \
33*607ca46eSDavid Howells 			(issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED))
34*607ca46eSDavid Howells 
35*607ca46eSDavid Howells /* When set, a process can retain its capabilities even after
36*607ca46eSDavid Howells    transitioning to a non-root user (the set-uid fixup suppressed by
37*607ca46eSDavid Howells    bit 2). Bit-4 is cleared when a process calls exec(); setting both
38*607ca46eSDavid Howells    bit 4 and 5 will create a barrier through exec that no exec()'d
39*607ca46eSDavid Howells    child can use this feature again. */
40*607ca46eSDavid Howells #define SECURE_KEEP_CAPS		4
41*607ca46eSDavid Howells #define SECURE_KEEP_CAPS_LOCKED		5  /* make bit-4 immutable */
42*607ca46eSDavid Howells 
43*607ca46eSDavid Howells #define SECBIT_KEEP_CAPS	(issecure_mask(SECURE_KEEP_CAPS))
44*607ca46eSDavid Howells #define SECBIT_KEEP_CAPS_LOCKED (issecure_mask(SECURE_KEEP_CAPS_LOCKED))
45*607ca46eSDavid Howells 
46*607ca46eSDavid Howells #define SECURE_ALL_BITS		(issecure_mask(SECURE_NOROOT) | \
47*607ca46eSDavid Howells 				 issecure_mask(SECURE_NO_SETUID_FIXUP) | \
48*607ca46eSDavid Howells 				 issecure_mask(SECURE_KEEP_CAPS))
49*607ca46eSDavid Howells #define SECURE_ALL_LOCKS	(SECURE_ALL_BITS << 1)
50*607ca46eSDavid Howells 
51*607ca46eSDavid Howells #endif /* _UAPI_LINUX_SECUREBITS_H */
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