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3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
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7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
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11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
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34 * @(#)kern_prot.c 8.6 (Berkeley) 1/21/94
35 * $FreeBSD: src/sys/kern/kern_prot.c,v 1.53.2.9 2002/03/09 05:20:26 dd Exp $
39 * System calls related to processes and protection
42 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/sysmsg.h>
46 #include <sys/kernel.h>
50 #include <sys/malloc.h>
51 #include <sys/pioctl.h>
52 #include <sys/resourcevar.h>
54 #include <sys/lockf.h>
55 #include <sys/spinlock.h>
57 #include <sys/spinlock2.h>
59 static MALLOC_DEFINE(M_CRED
, "cred", "credentials");
62 sys_getpid(struct sysmsg
*sysmsg
, const struct getpid_args
*uap
)
64 struct proc
*p
= curproc
;
66 sysmsg
->sysmsg_fds
[0] = p
->p_pid
;
71 sys_getppid(struct sysmsg
*sysmsg
, const struct getppid_args
*uap
)
73 struct proc
*p
= curproc
;
75 sysmsg
->sysmsg_result
= p
->p_ppid
;
81 sys_lwp_gettid(struct sysmsg
*sysmsg
, const struct lwp_gettid_args
*uap
)
83 struct lwp
*lp
= curthread
->td_lwp
;
84 sysmsg
->sysmsg_result
= lp
->lwp_tid
;
89 * Get process group ID; note that POSIX getpgrp takes no parameter
92 sys_getpgrp(struct sysmsg
*sysmsg
, const struct getpgrp_args
*uap
)
94 struct proc
*p
= curproc
;
96 lwkt_gettoken_shared(&p
->p_token
);
97 sysmsg
->sysmsg_result
= p
->p_pgrp
->pg_id
;
98 lwkt_reltoken(&p
->p_token
);
104 * Get an arbitrary pid's process group id
107 sys_getpgid(struct sysmsg
*sysmsg
, const struct getpgid_args
*uap
)
109 struct proc
*p
= curproc
;
119 pt
= pfind(uap
->pid
);
124 lwkt_gettoken_shared(&pt
->p_token
);
125 sysmsg
->sysmsg_result
= pt
->p_pgrp
->pg_id
;
126 lwkt_reltoken(&pt
->p_token
);
134 * Get an arbitrary pid's session id.
137 sys_getsid(struct sysmsg
*sysmsg
, const struct getsid_args
*uap
)
139 struct proc
*p
= curproc
;
149 pt
= pfind(uap
->pid
);
154 sysmsg
->sysmsg_result
= pt
->p_session
->s_sid
;
165 sys_getuid(struct sysmsg
*sysmsg
, const struct getuid_args
*uap
)
167 struct ucred
*cred
= curthread
->td_ucred
;
169 sysmsg
->sysmsg_fds
[0] = cred
->cr_ruid
;
177 sys_geteuid(struct sysmsg
*sysmsg
, const struct geteuid_args
*uap
)
179 struct ucred
*cred
= curthread
->td_ucred
;
181 sysmsg
->sysmsg_result
= cred
->cr_uid
;
189 sys_getgid(struct sysmsg
*sysmsg
, const struct getgid_args
*uap
)
191 struct ucred
*cred
= curthread
->td_ucred
;
193 sysmsg
->sysmsg_fds
[0] = cred
->cr_rgid
;
198 * Get effective group ID. The "egid" is groups[0], and could be obtained
199 * via getgroups. This syscall exists because it is somewhat painful to do
200 * correctly in a library function.
203 sys_getegid(struct sysmsg
*sysmsg
, const struct getegid_args
*uap
)
205 struct ucred
*cred
= curthread
->td_ucred
;
207 sysmsg
->sysmsg_result
= cred
->cr_groups
[0];
212 sys_getgroups(struct sysmsg
*sysmsg
, const struct getgroups_args
*uap
)
218 cr
= curthread
->td_ucred
;
219 if ((ngrp
= uap
->gidsetsize
) == 0) {
220 sysmsg
->sysmsg_result
= cr
->cr_ngroups
;
223 if (ngrp
< cr
->cr_ngroups
)
225 ngrp
= cr
->cr_ngroups
;
226 error
= copyout((caddr_t
)cr
->cr_groups
,
227 (caddr_t
)uap
->gidset
, ngrp
* sizeof(gid_t
));
229 sysmsg
->sysmsg_result
= ngrp
;
234 * Set the per-thread title for ps
237 sys_lwp_setname(struct sysmsg
*sysmsg
, const struct lwp_setname_args
*uap
)
239 struct proc
*p
= curproc
;
241 char buf
[LPMAP_MAXTHREADTITLE
];
245 if (uap
->name
!= NULL
) {
246 error
= copyinstr(uap
->name
, buf
, sizeof(buf
), &len
);
248 if (error
!= ENAMETOOLONG
)
250 buf
[sizeof(buf
)-1] = 0;
251 len
= sizeof(buf
) - 1;
258 lwkt_gettoken(&p
->p_token
);
260 lp
= lwpfind(p
, uap
->tid
);
262 lwkt_gettoken(&lp
->lwp_token
);
263 if (lp
->lwp_lpmap
== NULL
)
266 bcopy(buf
, lp
->lwp_lpmap
->thread_title
, len
);
267 lwkt_reltoken(&lp
->lwp_token
);
274 lwkt_reltoken(&p
->p_token
);
280 * Retrieve the per-thread title for ps
283 sys_lwp_getname(struct sysmsg
*sysmsg
, const struct lwp_getname_args
*uap
)
285 struct proc
*p
= curproc
;
287 char buf
[LPMAP_MAXTHREADTITLE
];
293 lwkt_gettoken(&p
->p_token
);
295 lp
= lwpfind(p
, uap
->tid
);
297 lwkt_gettoken(&lp
->lwp_token
);
298 if (lp
->lwp_lpmap
== NULL
)
301 for (len
= 0; len
< LPMAP_MAXTHREADTITLE
- 1 &&
302 len
< uap
->len
- 1; ++len
) {
303 c
= lp
->lwp_lpmap
->thread_title
[len
];
309 lwkt_reltoken(&lp
->lwp_token
);
317 lwkt_reltoken(&p
->p_token
);
320 error
= copyout(buf
, uap
->name
, len
);
326 sys_setsid(struct sysmsg
*sysmsg
, const struct setsid_args
*uap
)
328 struct proc
*p
= curproc
;
329 struct pgrp
*pg
= NULL
;
332 lwkt_gettoken(&p
->p_token
);
333 if (p
->p_pgid
== p
->p_pid
|| (pg
= pgfind(p
->p_pid
)) != NULL
) {
338 enterpgrp(p
, p
->p_pid
, 1);
339 sysmsg
->sysmsg_result
= p
->p_pid
;
342 lwkt_reltoken(&p
->p_token
);
347 * set process group (setpgid/old setpgrp)
349 * caller does setpgid(targpid, targpgid)
351 * pid must be caller or child of caller (ESRCH)
353 * pid must be in same session (EPERM)
354 * pid can't have done an exec (EACCES)
356 * there must exist some pid in same session having pgid (EPERM)
357 * pid must not be session leader (EPERM)
360 sys_setpgid(struct sysmsg
*sysmsg
, const struct setpgid_args
*uap
)
362 struct proc
*curp
= curproc
;
363 struct proc
*targp
; /* target process */
364 struct pgrp
*pgrp
= NULL
; /* target pgrp */
366 int pgid
= uap
->pgid
;
371 if (uap
->pid
!= 0 && uap
->pid
!= curp
->p_pid
) {
372 if ((targp
= pfind(uap
->pid
)) == NULL
|| !inferior(targp
)) {
379 lwkt_gettoken(&targp
->p_token
);
380 /* targp now referenced and its token is held */
382 if (targp
->p_pgrp
== NULL
||
383 targp
->p_session
!= curp
->p_session
) {
387 if (targp
->p_flags
& P_EXEC
) {
394 lwkt_gettoken(&targp
->p_token
);
396 if (SESS_LEADER(targp
)) {
402 } else if (pgid
!= targp
->p_pid
) {
403 if ((pgrp
= pgfind(pgid
)) == NULL
||
404 pgrp
->pg_session
!= curp
->p_session
) {
409 error
= enterpgrp(targp
, pgid
, 0);
414 lwkt_reltoken(&targp
->p_token
);
421 * Use the clause in B.4.2.2 that allows setuid/setgid to be 4.2/4.3BSD
422 * compatible. It says that setting the uid/gid to euid/egid is a special
423 * case of "appropriate privilege". Once the rules are expanded out, this
424 * basically means that setuid(nnn) sets all three id's, in all permitted
425 * cases unless _POSIX_SAVED_IDS is enabled. In that case, setuid(getuid())
426 * does not set the saved id - this is dangerous for traditional BSD
427 * programs. For this reason, we *really* do not want to set
428 * _POSIX_SAVED_IDS and do not want to clear POSIX_APPENDIX_B_4_2_2.
430 #define POSIX_APPENDIX_B_4_2_2
433 sys_setuid(struct sysmsg
*sysmsg
, const struct setuid_args
*uap
)
435 struct proc
*p
= curproc
;
440 lwkt_gettoken(&p
->p_token
);
444 * See if we have "permission" by POSIX 1003.1 rules.
446 * Note that setuid(geteuid()) is a special case of
447 * "appropriate privileges" in appendix B.4.2.2. We need
448 * to use this clause to be compatible with traditional BSD
449 * semantics. Basically, it means that "setuid(xx)" sets all
450 * three id's (assuming you have privs).
452 * Notes on the logic. We do things in three steps.
453 * 1: We determine if the euid is going to change, and do EPERM
454 * right away. We unconditionally change the euid later if this
455 * test is satisfied, simplifying that part of the logic.
456 * 2: We determine if the real and/or saved uid's are going to
457 * change. Determined by compile options.
458 * 3: Change euid last. (after tests in #2 for "appropriate privs")
461 if (uid
!= cr
->cr_ruid
&& /* allow setuid(getuid()) */
462 #ifdef _POSIX_SAVED_IDS
463 uid
!= crc
->cr_svuid
&& /* allow setuid(saved gid) */
465 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */
466 uid
!= cr
->cr_uid
&& /* allow setuid(geteuid()) */
468 (error
= caps_priv_check(cr
, SYSCAP_NOCRED_SETUID
)))
471 #ifdef _POSIX_SAVED_IDS
473 * Do we have "appropriate privileges" (are we root or uid == euid)
474 * If so, we are changing the real uid and/or saved uid.
477 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use the clause from B.4.2.2 */
480 caps_priv_check(cr
, SYSCAP_NOCRED_SETUID
, 0) == 0) /* using privs */
484 * Set the real uid and transfer proc count to new user.
486 if (uid
!= cr
->cr_ruid
) {
487 cr
= change_ruid(uid
);
493 * XXX always set saved uid even if not _POSIX_SAVED_IDS, as
494 * the security of seteuid() depends on it. B.4.2.2 says it
495 * is important that we should do this.
497 if (cr
->cr_svuid
!= uid
) {
505 * In all permitted cases, we are changing the euid.
506 * Copy credentials so other references do not see our changes.
508 if (cr
->cr_uid
!= uid
) {
514 lwkt_reltoken(&p
->p_token
);
519 sys_seteuid(struct sysmsg
*sysmsg
, const struct seteuid_args
*uap
)
521 struct proc
*p
= curproc
;
526 lwkt_gettoken(&p
->p_token
);
529 if (euid
!= cr
->cr_ruid
&& /* allow seteuid(getuid()) */
530 euid
!= cr
->cr_svuid
&& /* allow seteuid(saved uid) */
531 (error
= caps_priv_check(cr
, SYSCAP_NOCRED_SETEUID
)))
533 lwkt_reltoken(&p
->p_token
);
538 * Everything's okay, do it. Copy credentials so other references do
539 * not see our changes.
541 if (cr
->cr_uid
!= euid
) {
545 lwkt_reltoken(&p
->p_token
);
550 sys_setgid(struct sysmsg
*sysmsg
, const struct setgid_args
*uap
)
552 struct proc
*p
= curproc
;
557 lwkt_gettoken(&p
->p_token
);
561 * See if we have "permission" by POSIX 1003.1 rules.
563 * Note that setgid(getegid()) is a special case of
564 * "appropriate privileges" in appendix B.4.2.2. We need
565 * to use this clause to be compatible with traditional BSD
566 * semantics. Basically, it means that "setgid(xx)" sets all
567 * three id's (assuming you have privs).
569 * For notes on the logic here, see setuid() above.
572 if (gid
!= cr
->cr_rgid
&& /* allow setgid(getgid()) */
573 #ifdef _POSIX_SAVED_IDS
574 gid
!= cr
->cr_svgid
&& /* allow setgid(saved gid) */
576 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */
577 gid
!= cr
->cr_groups
[0] && /* allow setgid(getegid()) */
579 (error
= caps_priv_check(cr
, SYSCAP_NOCRED_SETGID
)))
584 #ifdef _POSIX_SAVED_IDS
586 * Do we have "appropriate privileges" (are we root or gid == egid)
587 * If so, we are changing the real uid and saved gid.
590 #ifdef POSIX_APPENDIX_B_4_2_2 /* use the clause from B.4.2.2 */
591 gid
== cr
->cr_groups
[0] ||
593 cpas_priv_check(cr
, SYSCAP_NOCRED_SETGID
) == 0) /* using privs */
599 if (cr
->cr_rgid
!= gid
) {
607 * XXX always set saved gid even if not _POSIX_SAVED_IDS, as
608 * the security of setegid() depends on it. B.4.2.2 says it
609 * is important that we should do this.
611 if (cr
->cr_svgid
!= gid
) {
618 * In all cases permitted cases, we are changing the egid.
619 * Copy credentials so other references do not see our changes.
621 if (cr
->cr_groups
[0] != gid
) {
623 cr
->cr_groups
[0] = gid
;
628 lwkt_reltoken(&p
->p_token
);
633 sys_setegid(struct sysmsg
*sysmsg
, const struct setegid_args
*uap
)
635 struct proc
*p
= curproc
;
640 lwkt_gettoken(&p
->p_token
);
643 if (egid
!= cr
->cr_rgid
&& /* allow setegid(getgid()) */
644 egid
!= cr
->cr_svgid
&& /* allow setegid(saved gid) */
645 (error
= caps_priv_check(cr
, SYSCAP_NOCRED_SETEGID
)))
649 if (cr
->cr_groups
[0] != egid
) {
651 cr
->cr_groups
[0] = egid
;
656 lwkt_reltoken(&p
->p_token
);
661 sys_setgroups(struct sysmsg
*sysmsg
, const struct setgroups_args
*uap
)
663 struct proc
*p
= curproc
;
668 lwkt_gettoken(&p
->p_token
);
671 if ((error
= caps_priv_check(cr
, SYSCAP_NOCRED_SETGROUPS
)))
673 ngrp
= uap
->gidsetsize
;
674 if (ngrp
> NGROUPS
) {
679 * XXX A little bit lazy here. We could test if anything has
680 * changed before cratom() and setting P_SUGID.
685 * setgroups(0, NULL) is a legitimate way of clearing the
686 * groups vector on non-BSD systems (which generally do not
687 * have the egid in the groups[0]). We risk security holes
688 * when running non-BSD software if we do not do the same.
692 error
= copyin(uap
->gidset
, cr
->cr_groups
,
693 ngrp
* sizeof(gid_t
));
696 cr
->cr_ngroups
= ngrp
;
701 lwkt_reltoken(&p
->p_token
);
706 sys_setreuid(struct sysmsg
*sysmsg
, const struct setreuid_args
*uap
)
708 struct proc
*p
= curproc
;
713 lwkt_gettoken(&p
->p_token
);
718 if (((ruid
!= (uid_t
)-1 && ruid
!= cr
->cr_ruid
&&
719 ruid
!= cr
->cr_svuid
) ||
720 (euid
!= (uid_t
)-1 && euid
!= cr
->cr_uid
&&
721 euid
!= cr
->cr_ruid
&& euid
!= cr
->cr_svuid
)) &&
722 (error
= caps_priv_check(cr
, SYSCAP_NOCRED_SETREUID
)) != 0)
727 if (euid
!= (uid_t
)-1 && cr
->cr_uid
!= euid
) {
728 cr
= change_euid(euid
);
731 if (ruid
!= (uid_t
)-1 && cr
->cr_ruid
!= ruid
) {
732 cr
= change_ruid(ruid
);
735 if ((ruid
!= (uid_t
)-1 || cr
->cr_uid
!= cr
->cr_ruid
) &&
736 cr
->cr_svuid
!= cr
->cr_uid
) {
738 cr
->cr_svuid
= cr
->cr_uid
;
743 lwkt_reltoken(&p
->p_token
);
748 sys_setregid(struct sysmsg
*sysmsg
, const struct setregid_args
*uap
)
750 struct proc
*p
= curproc
;
755 lwkt_gettoken(&p
->p_token
);
760 if (((rgid
!= (gid_t
)-1 && rgid
!= cr
->cr_rgid
&&
761 rgid
!= cr
->cr_svgid
) ||
762 (egid
!= (gid_t
)-1 && egid
!= cr
->cr_groups
[0] &&
763 egid
!= cr
->cr_rgid
&& egid
!= cr
->cr_svgid
)) &&
764 (error
= caps_priv_check(cr
, SYSCAP_NOCRED_SETREGID
)) != 0)
769 if (egid
!= (gid_t
)-1 && cr
->cr_groups
[0] != egid
) {
771 cr
->cr_groups
[0] = egid
;
774 if (rgid
!= (gid_t
)-1 && cr
->cr_rgid
!= rgid
) {
779 if ((rgid
!= (gid_t
)-1 || cr
->cr_groups
[0] != cr
->cr_rgid
) &&
780 cr
->cr_svgid
!= cr
->cr_groups
[0]) {
782 cr
->cr_svgid
= cr
->cr_groups
[0];
787 lwkt_reltoken(&p
->p_token
);
792 * setresuid(ruid, euid, suid) is like setreuid except control over the
793 * saved uid is explicit.
796 sys_setresuid(struct sysmsg
*sysmsg
, const struct setresuid_args
*uap
)
798 struct proc
*p
= curproc
;
800 uid_t ruid
, euid
, suid
;
803 lwkt_gettoken(&p
->p_token
);
809 if (((ruid
!= (uid_t
)-1 && ruid
!= cr
->cr_ruid
&&
810 ruid
!= cr
->cr_svuid
&& ruid
!= cr
->cr_uid
) ||
811 (euid
!= (uid_t
)-1 && euid
!= cr
->cr_ruid
&&
812 euid
!= cr
->cr_svuid
&& euid
!= cr
->cr_uid
) ||
813 (suid
!= (uid_t
)-1 && suid
!= cr
->cr_ruid
&&
814 suid
!= cr
->cr_svuid
&& suid
!= cr
->cr_uid
)) &&
815 (error
= caps_priv_check(cr
, SYSCAP_NOCRED_SETRESUID
)) != 0)
819 if (euid
!= (uid_t
)-1 && cr
->cr_uid
!= euid
) {
820 cr
= change_euid(euid
);
823 if (ruid
!= (uid_t
)-1 && cr
->cr_ruid
!= ruid
) {
824 cr
= change_ruid(ruid
);
827 if (suid
!= (uid_t
)-1 && cr
->cr_svuid
!= suid
) {
834 lwkt_reltoken(&p
->p_token
);
839 * setresgid(rgid, egid, sgid) is like setregid except control over the
840 * saved gid is explicit.
843 sys_setresgid(struct sysmsg
*sysmsg
, const struct setresgid_args
*uap
)
845 struct proc
*p
= curproc
;
847 gid_t rgid
, egid
, sgid
;
850 lwkt_gettoken(&p
->p_token
);
855 if (((rgid
!= (gid_t
)-1 && rgid
!= cr
->cr_rgid
&&
856 rgid
!= cr
->cr_svgid
&& rgid
!= cr
->cr_groups
[0]) ||
857 (egid
!= (gid_t
)-1 && egid
!= cr
->cr_rgid
&&
858 egid
!= cr
->cr_svgid
&& egid
!= cr
->cr_groups
[0]) ||
859 (sgid
!= (gid_t
)-1 && sgid
!= cr
->cr_rgid
&&
860 sgid
!= cr
->cr_svgid
&& sgid
!= cr
->cr_groups
[0])) &&
861 (error
= caps_priv_check(cr
, SYSCAP_NOCRED_SETRESGID
)) != 0)
866 if (egid
!= (gid_t
)-1 && cr
->cr_groups
[0] != egid
) {
868 cr
->cr_groups
[0] = egid
;
871 if (rgid
!= (gid_t
)-1 && cr
->cr_rgid
!= rgid
) {
876 if (sgid
!= (gid_t
)-1 && cr
->cr_svgid
!= sgid
) {
883 lwkt_reltoken(&p
->p_token
);
888 sys_getresuid(struct sysmsg
*sysmsg
, const struct getresuid_args
*uap
)
891 int error1
= 0, error2
= 0, error3
= 0;
894 * copyout's can fault synchronously so we cannot use a shared
897 cr
= curthread
->td_ucred
;
899 error1
= copyout((caddr_t
)&cr
->cr_ruid
,
900 (caddr_t
)uap
->ruid
, sizeof(cr
->cr_ruid
));
902 error2
= copyout((caddr_t
)&cr
->cr_uid
,
903 (caddr_t
)uap
->euid
, sizeof(cr
->cr_uid
));
905 error3
= copyout((caddr_t
)&cr
->cr_svuid
,
906 (caddr_t
)uap
->suid
, sizeof(cr
->cr_svuid
));
907 return error1
? error1
: (error2
? error2
: error3
);
911 sys_getresgid(struct sysmsg
*sysmsg
, const struct getresgid_args
*uap
)
914 int error1
= 0, error2
= 0, error3
= 0;
916 cr
= curthread
->td_ucred
;
918 error1
= copyout(&cr
->cr_rgid
, uap
->rgid
,
919 sizeof(cr
->cr_rgid
));
921 error2
= copyout(&cr
->cr_groups
[0], uap
->egid
,
922 sizeof(cr
->cr_groups
[0]));
924 error3
= copyout(&cr
->cr_svgid
, uap
->sgid
,
925 sizeof(cr
->cr_svgid
));
926 return error1
? error1
: (error2
? error2
: error3
);
931 * NOTE: OpenBSD sets a P_SUGIDEXEC flag set at execve() time,
932 * we use P_SUGID because we consider changing the owners as
933 * "tainting" as well.
934 * This is significant for procs that start as root and "become"
935 * a user without an exec - programs cannot know *everything*
936 * that libc *might* have put in their data segment.
939 sys_issetugid(struct sysmsg
*sysmsg
, const struct issetugid_args
*uap
)
941 sysmsg
->sysmsg_result
= (curproc
->p_flags
& P_SUGID
) ? 1 : 0;
946 * Check if gid is a member of the group set.
949 groupmember(gid_t gid
, struct ucred
*cred
)
954 egp
= &(cred
->cr_groups
[cred
->cr_ngroups
]);
955 for (gp
= cred
->cr_groups
; gp
< egp
; gp
++) {
964 * Test whether the specified credentials have the privilege
967 * A kernel thread without a process context is assumed to have
968 * the privilege in question. In situations where the caller always
969 * expect a cred to exist, the cred should be passed separately and
970 * priv_check_cred() should be used instead of priv_check().
972 * Returns 0 or error.
975 priv_check(struct thread
*td
, int priv
)
977 if (td
->td_lwp
!= NULL
)
978 return priv_check_cred(td
->td_ucred
, priv
, 0);
983 * Check a credential for privilege.
985 * A non-null credential is expected unless NULL_CRED_OKAY is set.
988 priv_check_cred(struct ucred
*cred
, int priv
, int flags
)
992 KASSERT(PRIV_VALID(priv
), ("priv_check_cred: invalid privilege"));
994 KASSERT(cred
!= NULL
|| (flags
& NULL_CRED_OKAY
),
995 ("priv_check_cred: NULL cred!"));
998 if (flags
& NULL_CRED_OKAY
)
1003 if (cred
->cr_uid
!= 0)
1006 error
= prison_priv_check(cred
, priv
);
1009 error
= caps_priv_check(cred
, priv
);
1013 /* NOTE: accounting for suser access (p_acflag/ASU) removed */
1020 * Return zero if p1 can signal p2, return errno (EPERM/ESRCH) otherwise.
1023 p_trespass(struct ucred
*cr1
, struct ucred
*cr2
)
1029 * Disallow signals crossing outside of a prison boundary
1031 if (!PRISON_CHECK(cr1
, cr2
))
1035 * Processes inside a restricted root cannot signal processes
1036 * outside of a restricted root. Unless it is also jailed, this will
1037 * still allow cross-signaling between unrelated restricted roots.
1039 if ((caps_get(cr1
, SYSCAP_RESTRICTEDROOT
) & __SYSCAP_SELF
) &&
1040 (caps_get(cr2
, SYSCAP_RESTRICTEDROOT
) & __SYSCAP_SELF
) == 0)
1045 if (cr1
->cr_ruid
== cr2
->cr_ruid
)
1047 if (cr1
->cr_uid
== cr2
->cr_ruid
)
1049 if (cr1
->cr_ruid
== cr2
->cr_uid
)
1051 if (cr1
->cr_uid
== cr2
->cr_uid
)
1053 if (caps_priv_check(cr1
, SYSCAP_NOPROC_TRESPASS
) == 0)
1055 if (cr1
->cr_uid
== 0)
1061 * Allocate a zeroed cred structure.
1068 cr
= kmalloc(sizeof(*cr
), M_CRED
, M_WAITOK
|M_ZERO
);
1075 * Claim another reference to a ucred structure. Can be used with special
1078 * It must be possible to call this routine with spinlocks held, meaning
1079 * that this routine itself cannot obtain a spinlock.
1082 crhold(struct ucred
*cr
)
1084 if (cr
!= NOCRED
&& cr
!= FSCRED
)
1085 atomic_add_long(&cr
->cr_ref
, 1);
1090 * Drop a reference from the cred structure, free it if the reference count
1093 * NOTE: because we used atomic_add_int() above, without a spinlock, we
1094 * must also use atomic_subtract_int() below. A spinlock is required
1095 * in crfree() to handle multiple callers racing the refcount to 0.
1098 crfree(struct ucred
*cr
)
1100 if (cr
->cr_ref
<= 0)
1101 panic("Freeing already free credential! %p", cr
);
1102 if (atomic_fetchadd_long(&cr
->cr_ref
, -1) == 1) {
1104 * Some callers of crget(), such as nfs_statfs(),
1105 * allocate a temporary credential, but don't
1106 * allocate a uidinfo structure.
1108 if (cr
->cr_uidinfo
!= NULL
) {
1109 uidrop(cr
->cr_uidinfo
);
1110 cr
->cr_uidinfo
= NULL
;
1112 if (cr
->cr_ruidinfo
!= NULL
) {
1113 uidrop(cr
->cr_ruidinfo
);
1114 cr
->cr_ruidinfo
= NULL
;
1118 * Destroy empty prisons
1121 prison_free(cr
->cr_prison
);
1122 cr
->cr_prison
= NULL
; /* safety */
1124 kfree((caddr_t
)cr
, M_CRED
);
1129 * Atomize a cred structure so it can be modified without polluting
1130 * other references to it.
1132 * MPSAFE (however, *pcr must be stable)
1135 cratom(struct ucred
**pcr
)
1137 struct ucred
*oldcr
;
1138 struct ucred
*newcr
;
1141 if (oldcr
->cr_ref
== 1)
1143 newcr
= crget(); /* this might block */
1144 oldcr
= *pcr
; /* re-cache after potentially blocking */
1146 uihold(newcr
->cr_uidinfo
);
1147 uihold(newcr
->cr_ruidinfo
);
1149 prison_hold(newcr
->cr_prison
);
1158 * Called with a modifying token held, but must still obtain p_spin to
1159 * actually replace p_ucred to handle races against syscall entry from
1160 * other threads which cache p_ucred->td_ucred.
1162 * (the threads will only get the spin-lock, and they only need to in
1163 * the case where td_ucred != p_ucred so this is optimal).
1166 cratom_proc(struct proc
*p
)
1168 struct ucred
*oldcr
;
1169 struct ucred
*newcr
;
1172 if (oldcr
->cr_ref
== 1)
1175 newcr
= crget(); /* this might block */
1176 oldcr
= p
->p_ucred
; /* so re-cache oldcr (do not re-test) */
1178 uihold(newcr
->cr_uidinfo
);
1179 uihold(newcr
->cr_ruidinfo
);
1181 prison_hold(newcr
->cr_prison
);
1184 spin_lock(&p
->p_spin
);
1186 spin_unlock(&p
->p_spin
);
1193 * Dup cred struct to a new held one.
1196 crdup(struct ucred
*cr
)
1198 struct ucred
*newcr
;
1202 uihold(newcr
->cr_uidinfo
);
1203 uihold(newcr
->cr_ruidinfo
);
1205 prison_hold(newcr
->cr_prison
);
1212 * Dup cred structure without caps or prison
1215 crdup_nocaps(struct ucred
*cr
)
1217 struct ucred
*newcr
;
1221 uihold(newcr
->cr_uidinfo
);
1222 uihold(newcr
->cr_ruidinfo
);
1223 newcr
->cr_prison
= NULL
;
1224 bzero(&newcr
->cr_caps
, sizeof(newcr
->cr_caps
));
1231 * Fill in a struct xucred based on a struct ucred.
1234 cru2x(struct ucred
*cr
, struct xucred
*xcr
)
1237 bzero(xcr
, sizeof(*xcr
));
1238 xcr
->cr_version
= XUCRED_VERSION
;
1239 xcr
->cr_uid
= cr
->cr_uid
;
1240 xcr
->cr_ngroups
= cr
->cr_ngroups
;
1241 bcopy(cr
->cr_groups
, xcr
->cr_groups
, sizeof(cr
->cr_groups
));
1245 * Get login name, if available.
1248 sys_getlogin(struct sysmsg
*sysmsg
, const struct getlogin_args
*uap
)
1250 struct proc
*p
= curproc
;
1251 char buf
[MAXLOGNAME
];
1255 namelen
= uap
->namelen
;
1256 if (namelen
> MAXLOGNAME
) /* namelen is unsigned */
1257 namelen
= MAXLOGNAME
;
1258 bzero(buf
, sizeof(buf
));
1259 lwkt_gettoken_shared(&p
->p_token
);
1260 bcopy(p
->p_pgrp
->pg_session
->s_login
, buf
, namelen
);
1261 lwkt_reltoken(&p
->p_token
);
1263 error
= copyout(buf
, uap
->namebuf
, namelen
);
1272 sys_setlogin(struct sysmsg
*sysmsg
, const struct setlogin_args
*uap
)
1274 struct thread
*td
= curthread
;
1277 char buf
[MAXLOGNAME
];
1280 cred
= td
->td_ucred
;
1283 if ((error
= caps_priv_check(cred
, SYSCAP_NOPROC_SETLOGIN
)))
1285 bzero(buf
, sizeof(buf
));
1286 error
= copyinstr(uap
->namebuf
, buf
, sizeof(buf
), NULL
);
1287 if (error
== ENAMETOOLONG
)
1290 lwkt_gettoken_shared(&p
->p_token
);
1291 memcpy(p
->p_pgrp
->pg_session
->s_login
, buf
, sizeof(buf
));
1292 lwkt_reltoken(&p
->p_token
);
1300 struct proc
*p
= curproc
;
1302 KKASSERT(p
!= NULL
);
1303 lwkt_gettoken(&p
->p_token
);
1304 p
->p_flags
|= P_SUGID
;
1305 if (!(p
->p_pfsflags
& PF_ISUGID
))
1307 lwkt_reltoken(&p
->p_token
);
1311 * Helper function to change the effective uid of a process
1314 change_euid(uid_t euid
)
1316 struct proc
*p
= curproc
;
1319 KKASSERT(p
!= NULL
);
1320 lf_count_adjust(p
, 0);
1321 cr
= cratom_proc(p
);
1323 uireplace(&cr
->cr_uidinfo
, uifind(euid
));
1324 lf_count_adjust(p
, 1);
1329 * Helper function to change the real uid of a process
1331 * The per-uid process count for this process is transfered from
1332 * the old uid to the new uid.
1335 change_ruid(uid_t ruid
)
1337 struct proc
*p
= curproc
;
1340 KKASSERT(p
!= NULL
);
1342 cr
= cratom_proc(p
);
1343 chgproccnt(cr
->cr_ruidinfo
, -1, 0);
1345 uireplace(&cr
->cr_ruidinfo
, uifind(ruid
));
1346 chgproccnt(cr
->cr_ruidinfo
, 1, 0);