FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_prot.c
1 /*-
2 * Copyright (c) 1982, 1986, 1989, 1990, 1991, 1993
3 * The Regents of the University of California.
4 * (c) UNIX System Laboratories, Inc.
5 * Copyright (c) 2000-2001 Robert N. M. Watson.
6 * All rights reserved.
7 *
8 * All or some portions of this file are derived from material licensed
9 * to the University of California by American Telephone and Telegraph
10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
11 * the permission of UNIX System Laboratories, Inc.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 * @(#)kern_prot.c 8.6 (Berkeley) 1/21/94
38 */
39
40 /*
41 * System calls related to processes and protection
42 */
43
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46
47 #include "opt_compat.h"
48 #include "opt_inet.h"
49 #include "opt_inet6.h"
50
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/acct.h>
54 #include <sys/kdb.h>
55 #include <sys/kernel.h>
56 #include <sys/lock.h>
57 #include <sys/loginclass.h>
58 #include <sys/malloc.h>
59 #include <sys/mutex.h>
60 #include <sys/refcount.h>
61 #include <sys/sx.h>
62 #include <sys/priv.h>
63 #include <sys/proc.h>
64 #include <sys/sysproto.h>
65 #include <sys/jail.h>
66 #include <sys/pioctl.h>
67 #include <sys/racct.h>
68 #include <sys/rctl.h>
69 #include <sys/resourcevar.h>
70 #include <sys/socket.h>
71 #include <sys/socketvar.h>
72 #include <sys/syscallsubr.h>
73 #include <sys/sysctl.h>
74
75 #ifdef REGRESSION
76 FEATURE(regression,
77 "Kernel support for interfaces necessary for regression testing (SECURITY RISK!)");
78 #endif
79
80 #if defined(INET) || defined(INET6)
81 #include <netinet/in.h>
82 #include <netinet/in_pcb.h>
83 #endif
84
85 #include <security/audit/audit.h>
86 #include <security/mac/mac_framework.h>
87
88 static MALLOC_DEFINE(M_CRED, "cred", "credentials");
89
90 SYSCTL_NODE(_security, OID_AUTO, bsd, CTLFLAG_RW, 0, "BSD security policy");
91
92 static void crsetgroups_locked(struct ucred *cr, int ngrp,
93 gid_t *groups);
94
95 #ifndef _SYS_SYSPROTO_H_
96 struct getpid_args {
97 int dummy;
98 };
99 #endif
100 /* ARGSUSED */
101 int
102 sys_getpid(struct thread *td, struct getpid_args *uap)
103 {
104 struct proc *p = td->td_proc;
105
106 td->td_retval[0] = p->p_pid;
107 #if defined(COMPAT_43)
108 td->td_retval[1] = kern_getppid(td);
109 #endif
110 return (0);
111 }
112
113 #ifndef _SYS_SYSPROTO_H_
114 struct getppid_args {
115 int dummy;
116 };
117 #endif
118 /* ARGSUSED */
119 int
120 sys_getppid(struct thread *td, struct getppid_args *uap)
121 {
122
123 td->td_retval[0] = kern_getppid(td);
124 return (0);
125 }
126
127 int
128 kern_getppid(struct thread *td)
129 {
130 struct proc *p = td->td_proc;
131 struct proc *pp;
132 int ppid;
133
134 PROC_LOCK(p);
135 if (!(p->p_flag & P_TRACED)) {
136 ppid = p->p_pptr->p_pid;
137 PROC_UNLOCK(p);
138 } else {
139 PROC_UNLOCK(p);
140 sx_slock(&proctree_lock);
141 pp = proc_realparent(p);
142 ppid = pp->p_pid;
143 sx_sunlock(&proctree_lock);
144 }
145
146 return (ppid);
147 }
148
149 /*
150 * Get process group ID; note that POSIX getpgrp takes no parameter.
151 */
152 #ifndef _SYS_SYSPROTO_H_
153 struct getpgrp_args {
154 int dummy;
155 };
156 #endif
157 int
158 sys_getpgrp(struct thread *td, struct getpgrp_args *uap)
159 {
160 struct proc *p = td->td_proc;
161
162 PROC_LOCK(p);
163 td->td_retval[0] = p->p_pgrp->pg_id;
164 PROC_UNLOCK(p);
165 return (0);
166 }
167
168 /* Get an arbitrary pid's process group id */
169 #ifndef _SYS_SYSPROTO_H_
170 struct getpgid_args {
171 pid_t pid;
172 };
173 #endif
174 int
175 sys_getpgid(struct thread *td, struct getpgid_args *uap)
176 {
177 struct proc *p;
178 int error;
179
180 if (uap->pid == 0) {
181 p = td->td_proc;
182 PROC_LOCK(p);
183 } else {
184 p = pfind(uap->pid);
185 if (p == NULL)
186 return (ESRCH);
187 error = p_cansee(td, p);
188 if (error) {
189 PROC_UNLOCK(p);
190 return (error);
191 }
192 }
193 td->td_retval[0] = p->p_pgrp->pg_id;
194 PROC_UNLOCK(p);
195 return (0);
196 }
197
198 /*
199 * Get an arbitrary pid's session id.
200 */
201 #ifndef _SYS_SYSPROTO_H_
202 struct getsid_args {
203 pid_t pid;
204 };
205 #endif
206 int
207 sys_getsid(struct thread *td, struct getsid_args *uap)
208 {
209 struct proc *p;
210 int error;
211
212 if (uap->pid == 0) {
213 p = td->td_proc;
214 PROC_LOCK(p);
215 } else {
216 p = pfind(uap->pid);
217 if (p == NULL)
218 return (ESRCH);
219 error = p_cansee(td, p);
220 if (error) {
221 PROC_UNLOCK(p);
222 return (error);
223 }
224 }
225 td->td_retval[0] = p->p_session->s_sid;
226 PROC_UNLOCK(p);
227 return (0);
228 }
229
230 #ifndef _SYS_SYSPROTO_H_
231 struct getuid_args {
232 int dummy;
233 };
234 #endif
235 /* ARGSUSED */
236 int
237 sys_getuid(struct thread *td, struct getuid_args *uap)
238 {
239
240 td->td_retval[0] = td->td_ucred->cr_ruid;
241 #if defined(COMPAT_43)
242 td->td_retval[1] = td->td_ucred->cr_uid;
243 #endif
244 return (0);
245 }
246
247 #ifndef _SYS_SYSPROTO_H_
248 struct geteuid_args {
249 int dummy;
250 };
251 #endif
252 /* ARGSUSED */
253 int
254 sys_geteuid(struct thread *td, struct geteuid_args *uap)
255 {
256
257 td->td_retval[0] = td->td_ucred->cr_uid;
258 return (0);
259 }
260
261 #ifndef _SYS_SYSPROTO_H_
262 struct getgid_args {
263 int dummy;
264 };
265 #endif
266 /* ARGSUSED */
267 int
268 sys_getgid(struct thread *td, struct getgid_args *uap)
269 {
270
271 td->td_retval[0] = td->td_ucred->cr_rgid;
272 #if defined(COMPAT_43)
273 td->td_retval[1] = td->td_ucred->cr_groups[0];
274 #endif
275 return (0);
276 }
277
278 /*
279 * Get effective group ID. The "egid" is groups[0], and could be obtained
280 * via getgroups. This syscall exists because it is somewhat painful to do
281 * correctly in a library function.
282 */
283 #ifndef _SYS_SYSPROTO_H_
284 struct getegid_args {
285 int dummy;
286 };
287 #endif
288 /* ARGSUSED */
289 int
290 sys_getegid(struct thread *td, struct getegid_args *uap)
291 {
292
293 td->td_retval[0] = td->td_ucred->cr_groups[0];
294 return (0);
295 }
296
297 #ifndef _SYS_SYSPROTO_H_
298 struct getgroups_args {
299 u_int gidsetsize;
300 gid_t *gidset;
301 };
302 #endif
303 int
304 sys_getgroups(struct thread *td, struct getgroups_args *uap)
305 {
306 struct ucred *cred;
307 u_int ngrp;
308 int error;
309
310 cred = td->td_ucred;
311 ngrp = cred->cr_ngroups;
312
313 if (uap->gidsetsize == 0) {
314 error = 0;
315 goto out;
316 }
317 if (uap->gidsetsize < ngrp)
318 return (EINVAL);
319
320 error = copyout(cred->cr_groups, uap->gidset, ngrp * sizeof(gid_t));
321 out:
322 td->td_retval[0] = ngrp;
323 return (error);
324 }
325
326 #ifndef _SYS_SYSPROTO_H_
327 struct setsid_args {
328 int dummy;
329 };
330 #endif
331 /* ARGSUSED */
332 int
333 sys_setsid(struct thread *td, struct setsid_args *uap)
334 {
335 struct pgrp *pgrp;
336 int error;
337 struct proc *p = td->td_proc;
338 struct pgrp *newpgrp;
339 struct session *newsess;
340
341 error = 0;
342 pgrp = NULL;
343
344 newpgrp = malloc(sizeof(struct pgrp), M_PGRP, M_WAITOK | M_ZERO);
345 newsess = malloc(sizeof(struct session), M_SESSION, M_WAITOK | M_ZERO);
346
347 sx_xlock(&proctree_lock);
348
349 if (p->p_pgid == p->p_pid || (pgrp = pgfind(p->p_pid)) != NULL) {
350 if (pgrp != NULL)
351 PGRP_UNLOCK(pgrp);
352 error = EPERM;
353 } else {
354 (void)enterpgrp(p, p->p_pid, newpgrp, newsess);
355 td->td_retval[0] = p->p_pid;
356 newpgrp = NULL;
357 newsess = NULL;
358 }
359
360 sx_xunlock(&proctree_lock);
361
362 if (newpgrp != NULL)
363 free(newpgrp, M_PGRP);
364 if (newsess != NULL)
365 free(newsess, M_SESSION);
366
367 return (error);
368 }
369
370 /*
371 * set process group (setpgid/old setpgrp)
372 *
373 * caller does setpgid(targpid, targpgid)
374 *
375 * pid must be caller or child of caller (ESRCH)
376 * if a child
377 * pid must be in same session (EPERM)
378 * pid can't have done an exec (EACCES)
379 * if pgid != pid
380 * there must exist some pid in same session having pgid (EPERM)
381 * pid must not be session leader (EPERM)
382 */
383 #ifndef _SYS_SYSPROTO_H_
384 struct setpgid_args {
385 int pid; /* target process id */
386 int pgid; /* target pgrp id */
387 };
388 #endif
389 /* ARGSUSED */
390 int
391 sys_setpgid(struct thread *td, struct setpgid_args *uap)
392 {
393 struct proc *curp = td->td_proc;
394 struct proc *targp; /* target process */
395 struct pgrp *pgrp; /* target pgrp */
396 int error;
397 struct pgrp *newpgrp;
398
399 if (uap->pgid < 0)
400 return (EINVAL);
401
402 error = 0;
403
404 newpgrp = malloc(sizeof(struct pgrp), M_PGRP, M_WAITOK | M_ZERO);
405
406 sx_xlock(&proctree_lock);
407 if (uap->pid != 0 && uap->pid != curp->p_pid) {
408 if ((targp = pfind(uap->pid)) == NULL) {
409 error = ESRCH;
410 goto done;
411 }
412 if (!inferior(targp)) {
413 PROC_UNLOCK(targp);
414 error = ESRCH;
415 goto done;
416 }
417 if ((error = p_cansee(td, targp))) {
418 PROC_UNLOCK(targp);
419 goto done;
420 }
421 if (targp->p_pgrp == NULL ||
422 targp->p_session != curp->p_session) {
423 PROC_UNLOCK(targp);
424 error = EPERM;
425 goto done;
426 }
427 if (targp->p_flag & P_EXEC) {
428 PROC_UNLOCK(targp);
429 error = EACCES;
430 goto done;
431 }
432 PROC_UNLOCK(targp);
433 } else
434 targp = curp;
435 if (SESS_LEADER(targp)) {
436 error = EPERM;
437 goto done;
438 }
439 if (uap->pgid == 0)
440 uap->pgid = targp->p_pid;
441 if ((pgrp = pgfind(uap->pgid)) == NULL) {
442 if (uap->pgid == targp->p_pid) {
443 error = enterpgrp(targp, uap->pgid, newpgrp,
444 NULL);
445 if (error == 0)
446 newpgrp = NULL;
447 } else
448 error = EPERM;
449 } else {
450 if (pgrp == targp->p_pgrp) {
451 PGRP_UNLOCK(pgrp);
452 goto done;
453 }
454 if (pgrp->pg_id != targp->p_pid &&
455 pgrp->pg_session != curp->p_session) {
456 PGRP_UNLOCK(pgrp);
457 error = EPERM;
458 goto done;
459 }
460 PGRP_UNLOCK(pgrp);
461 error = enterthispgrp(targp, pgrp);
462 }
463 done:
464 sx_xunlock(&proctree_lock);
465 KASSERT((error == 0) || (newpgrp != NULL),
466 ("setpgid failed and newpgrp is NULL"));
467 if (newpgrp != NULL)
468 free(newpgrp, M_PGRP);
469 return (error);
470 }
471
472 /*
473 * Use the clause in B.4.2.2 that allows setuid/setgid to be 4.2/4.3BSD
474 * compatible. It says that setting the uid/gid to euid/egid is a special
475 * case of "appropriate privilege". Once the rules are expanded out, this
476 * basically means that setuid(nnn) sets all three id's, in all permitted
477 * cases unless _POSIX_SAVED_IDS is enabled. In that case, setuid(getuid())
478 * does not set the saved id - this is dangerous for traditional BSD
479 * programs. For this reason, we *really* do not want to set
480 * _POSIX_SAVED_IDS and do not want to clear POSIX_APPENDIX_B_4_2_2.
481 */
482 #define POSIX_APPENDIX_B_4_2_2
483
484 #ifndef _SYS_SYSPROTO_H_
485 struct setuid_args {
486 uid_t uid;
487 };
488 #endif
489 /* ARGSUSED */
490 int
491 sys_setuid(struct thread *td, struct setuid_args *uap)
492 {
493 struct proc *p = td->td_proc;
494 struct ucred *newcred, *oldcred;
495 uid_t uid;
496 struct uidinfo *uip;
497 int error;
498
499 uid = uap->uid;
500 AUDIT_ARG_UID(uid);
501 newcred = crget();
502 uip = uifind(uid);
503 PROC_LOCK(p);
504 /*
505 * Copy credentials so other references do not see our changes.
506 */
507 oldcred = crcopysafe(p, newcred);
508
509 #ifdef MAC
510 error = mac_cred_check_setuid(oldcred, uid);
511 if (error)
512 goto fail;
513 #endif
514
515 /*
516 * See if we have "permission" by POSIX 1003.1 rules.
517 *
518 * Note that setuid(geteuid()) is a special case of
519 * "appropriate privileges" in appendix B.4.2.2. We need
520 * to use this clause to be compatible with traditional BSD
521 * semantics. Basically, it means that "setuid(xx)" sets all
522 * three id's (assuming you have privs).
523 *
524 * Notes on the logic. We do things in three steps.
525 * 1: We determine if the euid is going to change, and do EPERM
526 * right away. We unconditionally change the euid later if this
527 * test is satisfied, simplifying that part of the logic.
528 * 2: We determine if the real and/or saved uids are going to
529 * change. Determined by compile options.
530 * 3: Change euid last. (after tests in #2 for "appropriate privs")
531 */
532 if (uid != oldcred->cr_ruid && /* allow setuid(getuid()) */
533 #ifdef _POSIX_SAVED_IDS
534 uid != oldcred->cr_svuid && /* allow setuid(saved gid) */
535 #endif
536 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */
537 uid != oldcred->cr_uid && /* allow setuid(geteuid()) */
538 #endif
539 (error = priv_check_cred(oldcred, PRIV_CRED_SETUID, 0)) != 0)
540 goto fail;
541
542 #ifdef _POSIX_SAVED_IDS
543 /*
544 * Do we have "appropriate privileges" (are we root or uid == euid)
545 * If so, we are changing the real uid and/or saved uid.
546 */
547 if (
548 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use the clause from B.4.2.2 */
549 uid == oldcred->cr_uid ||
550 #endif
551 /* We are using privs. */
552 priv_check_cred(oldcred, PRIV_CRED_SETUID, 0) == 0)
553 #endif
554 {
555 /*
556 * Set the real uid and transfer proc count to new user.
557 */
558 if (uid != oldcred->cr_ruid) {
559 change_ruid(newcred, uip);
560 setsugid(p);
561 }
562 /*
563 * Set saved uid
564 *
565 * XXX always set saved uid even if not _POSIX_SAVED_IDS, as
566 * the security of seteuid() depends on it. B.4.2.2 says it
567 * is important that we should do this.
568 */
569 if (uid != oldcred->cr_svuid) {
570 change_svuid(newcred, uid);
571 setsugid(p);
572 }
573 }
574
575 /*
576 * In all permitted cases, we are changing the euid.
577 */
578 if (uid != oldcred->cr_uid) {
579 change_euid(newcred, uip);
580 setsugid(p);
581 }
582 proc_set_cred(p, newcred);
583 #ifdef RACCT
584 racct_proc_ucred_changed(p, oldcred, newcred);
585 crhold(newcred);
586 #endif
587 PROC_UNLOCK(p);
588 #ifdef RCTL
589 rctl_proc_ucred_changed(p, newcred);
590 crfree(newcred);
591 #endif
592 uifree(uip);
593 crfree(oldcred);
594 return (0);
595
596 fail:
597 PROC_UNLOCK(p);
598 uifree(uip);
599 crfree(newcred);
600 return (error);
601 }
602
603 #ifndef _SYS_SYSPROTO_H_
604 struct seteuid_args {
605 uid_t euid;
606 };
607 #endif
608 /* ARGSUSED */
609 int
610 sys_seteuid(struct thread *td, struct seteuid_args *uap)
611 {
612 struct proc *p = td->td_proc;
613 struct ucred *newcred, *oldcred;
614 uid_t euid;
615 struct uidinfo *euip;
616 int error;
617
618 euid = uap->euid;
619 AUDIT_ARG_EUID(euid);
620 newcred = crget();
621 euip = uifind(euid);
622 PROC_LOCK(p);
623 /*
624 * Copy credentials so other references do not see our changes.
625 */
626 oldcred = crcopysafe(p, newcred);
627
628 #ifdef MAC
629 error = mac_cred_check_seteuid(oldcred, euid);
630 if (error)
631 goto fail;
632 #endif
633
634 if (euid != oldcred->cr_ruid && /* allow seteuid(getuid()) */
635 euid != oldcred->cr_svuid && /* allow seteuid(saved uid) */
636 (error = priv_check_cred(oldcred, PRIV_CRED_SETEUID, 0)) != 0)
637 goto fail;
638
639 /*
640 * Everything's okay, do it.
641 */
642 if (oldcred->cr_uid != euid) {
643 change_euid(newcred, euip);
644 setsugid(p);
645 }
646 proc_set_cred(p, newcred);
647 PROC_UNLOCK(p);
648 uifree(euip);
649 crfree(oldcred);
650 return (0);
651
652 fail:
653 PROC_UNLOCK(p);
654 uifree(euip);
655 crfree(newcred);
656 return (error);
657 }
658
659 #ifndef _SYS_SYSPROTO_H_
660 struct setgid_args {
661 gid_t gid;
662 };
663 #endif
664 /* ARGSUSED */
665 int
666 sys_setgid(struct thread *td, struct setgid_args *uap)
667 {
668 struct proc *p = td->td_proc;
669 struct ucred *newcred, *oldcred;
670 gid_t gid;
671 int error;
672
673 gid = uap->gid;
674 AUDIT_ARG_GID(gid);
675 newcred = crget();
676 PROC_LOCK(p);
677 oldcred = crcopysafe(p, newcred);
678
679 #ifdef MAC
680 error = mac_cred_check_setgid(oldcred, gid);
681 if (error)
682 goto fail;
683 #endif
684
685 /*
686 * See if we have "permission" by POSIX 1003.1 rules.
687 *
688 * Note that setgid(getegid()) is a special case of
689 * "appropriate privileges" in appendix B.4.2.2. We need
690 * to use this clause to be compatible with traditional BSD
691 * semantics. Basically, it means that "setgid(xx)" sets all
692 * three id's (assuming you have privs).
693 *
694 * For notes on the logic here, see setuid() above.
695 */
696 if (gid != oldcred->cr_rgid && /* allow setgid(getgid()) */
697 #ifdef _POSIX_SAVED_IDS
698 gid != oldcred->cr_svgid && /* allow setgid(saved gid) */
699 #endif
700 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */
701 gid != oldcred->cr_groups[0] && /* allow setgid(getegid()) */
702 #endif
703 (error = priv_check_cred(oldcred, PRIV_CRED_SETGID, 0)) != 0)
704 goto fail;
705
706 #ifdef _POSIX_SAVED_IDS
707 /*
708 * Do we have "appropriate privileges" (are we root or gid == egid)
709 * If so, we are changing the real uid and saved gid.
710 */
711 if (
712 #ifdef POSIX_APPENDIX_B_4_2_2 /* use the clause from B.4.2.2 */
713 gid == oldcred->cr_groups[0] ||
714 #endif
715 /* We are using privs. */
716 priv_check_cred(oldcred, PRIV_CRED_SETGID, 0) == 0)
717 #endif
718 {
719 /*
720 * Set real gid
721 */
722 if (oldcred->cr_rgid != gid) {
723 change_rgid(newcred, gid);
724 setsugid(p);
725 }
726 /*
727 * Set saved gid
728 *
729 * XXX always set saved gid even if not _POSIX_SAVED_IDS, as
730 * the security of setegid() depends on it. B.4.2.2 says it
731 * is important that we should do this.
732 */
733 if (oldcred->cr_svgid != gid) {
734 change_svgid(newcred, gid);
735 setsugid(p);
736 }
737 }
738 /*
739 * In all cases permitted cases, we are changing the egid.
740 * Copy credentials so other references do not see our changes.
741 */
742 if (oldcred->cr_groups[0] != gid) {
743 change_egid(newcred, gid);
744 setsugid(p);
745 }
746 proc_set_cred(p, newcred);
747 PROC_UNLOCK(p);
748 crfree(oldcred);
749 return (0);
750
751 fail:
752 PROC_UNLOCK(p);
753 crfree(newcred);
754 return (error);
755 }
756
757 #ifndef _SYS_SYSPROTO_H_
758 struct setegid_args {
759 gid_t egid;
760 };
761 #endif
762 /* ARGSUSED */
763 int
764 sys_setegid(struct thread *td, struct setegid_args *uap)
765 {
766 struct proc *p = td->td_proc;
767 struct ucred *newcred, *oldcred;
768 gid_t egid;
769 int error;
770
771 egid = uap->egid;
772 AUDIT_ARG_EGID(egid);
773 newcred = crget();
774 PROC_LOCK(p);
775 oldcred = crcopysafe(p, newcred);
776
777 #ifdef MAC
778 error = mac_cred_check_setegid(oldcred, egid);
779 if (error)
780 goto fail;
781 #endif
782
783 if (egid != oldcred->cr_rgid && /* allow setegid(getgid()) */
784 egid != oldcred->cr_svgid && /* allow setegid(saved gid) */
785 (error = priv_check_cred(oldcred, PRIV_CRED_SETEGID, 0)) != 0)
786 goto fail;
787
788 if (oldcred->cr_groups[0] != egid) {
789 change_egid(newcred, egid);
790 setsugid(p);
791 }
792 proc_set_cred(p, newcred);
793 PROC_UNLOCK(p);
794 crfree(oldcred);
795 return (0);
796
797 fail:
798 PROC_UNLOCK(p);
799 crfree(newcred);
800 return (error);
801 }
802
803 #ifndef _SYS_SYSPROTO_H_
804 struct setgroups_args {
805 u_int gidsetsize;
806 gid_t *gidset;
807 };
808 #endif
809 /* ARGSUSED */
810 int
811 sys_setgroups(struct thread *td, struct setgroups_args *uap)
812 {
813 gid_t smallgroups[XU_NGROUPS];
814 gid_t *groups;
815 u_int gidsetsize;
816 int error;
817
818 gidsetsize = uap->gidsetsize;
819 if (gidsetsize > ngroups_max + 1)
820 return (EINVAL);
821
822 if (gidsetsize > XU_NGROUPS)
823 groups = malloc(gidsetsize * sizeof(gid_t), M_TEMP, M_WAITOK);
824 else
825 groups = smallgroups;
826
827 error = copyin(uap->gidset, groups, gidsetsize * sizeof(gid_t));
828 if (error == 0)
829 error = kern_setgroups(td, gidsetsize, groups);
830
831 if (gidsetsize > XU_NGROUPS)
832 free(groups, M_TEMP);
833 return (error);
834 }
835
836 int
837 kern_setgroups(struct thread *td, u_int ngrp, gid_t *groups)
838 {
839 struct proc *p = td->td_proc;
840 struct ucred *newcred, *oldcred;
841 int error;
842
843 MPASS(ngrp <= ngroups_max + 1);
844 AUDIT_ARG_GROUPSET(groups, ngrp);
845 newcred = crget();
846 crextend(newcred, ngrp);
847 PROC_LOCK(p);
848 oldcred = crcopysafe(p, newcred);
849
850 #ifdef MAC
851 error = mac_cred_check_setgroups(oldcred, ngrp, groups);
852 if (error)
853 goto fail;
854 #endif
855
856 error = priv_check_cred(oldcred, PRIV_CRED_SETGROUPS, 0);
857 if (error)
858 goto fail;
859
860 if (ngrp == 0) {
861 /*
862 * setgroups(0, NULL) is a legitimate way of clearing the
863 * groups vector on non-BSD systems (which generally do not
864 * have the egid in the groups[0]). We risk security holes
865 * when running non-BSD software if we do not do the same.
866 */
867 newcred->cr_ngroups = 1;
868 } else {
869 crsetgroups_locked(newcred, ngrp, groups);
870 }
871 setsugid(p);
872 proc_set_cred(p, newcred);
873 PROC_UNLOCK(p);
874 crfree(oldcred);
875 return (0);
876
877 fail:
878 PROC_UNLOCK(p);
879 crfree(newcred);
880 return (error);
881 }
882
883 #ifndef _SYS_SYSPROTO_H_
884 struct setreuid_args {
885 uid_t ruid;
886 uid_t euid;
887 };
888 #endif
889 /* ARGSUSED */
890 int
891 sys_setreuid(struct thread *td, struct setreuid_args *uap)
892 {
893 struct proc *p = td->td_proc;
894 struct ucred *newcred, *oldcred;
895 uid_t euid, ruid;
896 struct uidinfo *euip, *ruip;
897 int error;
898
899 euid = uap->euid;
900 ruid = uap->ruid;
901 AUDIT_ARG_EUID(euid);
902 AUDIT_ARG_RUID(ruid);
903 newcred = crget();
904 euip = uifind(euid);
905 ruip = uifind(ruid);
906 PROC_LOCK(p);
907 oldcred = crcopysafe(p, newcred);
908
909 #ifdef MAC
910 error = mac_cred_check_setreuid(oldcred, ruid, euid);
911 if (error)
912 goto fail;
913 #endif
914
915 if (((ruid != (uid_t)-1 && ruid != oldcred->cr_ruid &&
916 ruid != oldcred->cr_svuid) ||
917 (euid != (uid_t)-1 && euid != oldcred->cr_uid &&
918 euid != oldcred->cr_ruid && euid != oldcred->cr_svuid)) &&
919 (error = priv_check_cred(oldcred, PRIV_CRED_SETREUID, 0)) != 0)
920 goto fail;
921
922 if (euid != (uid_t)-1 && oldcred->cr_uid != euid) {
923 change_euid(newcred, euip);
924 setsugid(p);
925 }
926 if (ruid != (uid_t)-1 && oldcred->cr_ruid != ruid) {
927 change_ruid(newcred, ruip);
928 setsugid(p);
929 }
930 if ((ruid != (uid_t)-1 || newcred->cr_uid != newcred->cr_ruid) &&
931 newcred->cr_svuid != newcred->cr_uid) {
932 change_svuid(newcred, newcred->cr_uid);
933 setsugid(p);
934 }
935 proc_set_cred(p, newcred);
936 #ifdef RACCT
937 racct_proc_ucred_changed(p, oldcred, newcred);
938 crhold(newcred);
939 #endif
940 PROC_UNLOCK(p);
941 #ifdef RCTL
942 rctl_proc_ucred_changed(p, newcred);
943 crfree(newcred);
944 #endif
945 uifree(ruip);
946 uifree(euip);
947 crfree(oldcred);
948 return (0);
949
950 fail:
951 PROC_UNLOCK(p);
952 uifree(ruip);
953 uifree(euip);
954 crfree(newcred);
955 return (error);
956 }
957
958 #ifndef _SYS_SYSPROTO_H_
959 struct setregid_args {
960 gid_t rgid;
961 gid_t egid;
962 };
963 #endif
964 /* ARGSUSED */
965 int
966 sys_setregid(struct thread *td, struct setregid_args *uap)
967 {
968 struct proc *p = td->td_proc;
969 struct ucred *newcred, *oldcred;
970 gid_t egid, rgid;
971 int error;
972
973 egid = uap->egid;
974 rgid = uap->rgid;
975 AUDIT_ARG_EGID(egid);
976 AUDIT_ARG_RGID(rgid);
977 newcred = crget();
978 PROC_LOCK(p);
979 oldcred = crcopysafe(p, newcred);
980
981 #ifdef MAC
982 error = mac_cred_check_setregid(oldcred, rgid, egid);
983 if (error)
984 goto fail;
985 #endif
986
987 if (((rgid != (gid_t)-1 && rgid != oldcred->cr_rgid &&
988 rgid != oldcred->cr_svgid) ||
989 (egid != (gid_t)-1 && egid != oldcred->cr_groups[0] &&
990 egid != oldcred->cr_rgid && egid != oldcred->cr_svgid)) &&
991 (error = priv_check_cred(oldcred, PRIV_CRED_SETREGID, 0)) != 0)
992 goto fail;
993
994 if (egid != (gid_t)-1 && oldcred->cr_groups[0] != egid) {
995 change_egid(newcred, egid);
996 setsugid(p);
997 }
998 if (rgid != (gid_t)-1 && oldcred->cr_rgid != rgid) {
999 change_rgid(newcred, rgid);
1000 setsugid(p);
1001 }
1002 if ((rgid != (gid_t)-1 || newcred->cr_groups[0] != newcred->cr_rgid) &&
1003 newcred->cr_svgid != newcred->cr_groups[0]) {
1004 change_svgid(newcred, newcred->cr_groups[0]);
1005 setsugid(p);
1006 }
1007 proc_set_cred(p, newcred);
1008 PROC_UNLOCK(p);
1009 crfree(oldcred);
1010 return (0);
1011
1012 fail:
1013 PROC_UNLOCK(p);
1014 crfree(newcred);
1015 return (error);
1016 }
1017
1018 /*
1019 * setresuid(ruid, euid, suid) is like setreuid except control over the saved
1020 * uid is explicit.
1021 */
1022 #ifndef _SYS_SYSPROTO_H_
1023 struct setresuid_args {
1024 uid_t ruid;
1025 uid_t euid;
1026 uid_t suid;
1027 };
1028 #endif
1029 /* ARGSUSED */
1030 int
1031 sys_setresuid(struct thread *td, struct setresuid_args *uap)
1032 {
1033 struct proc *p = td->td_proc;
1034 struct ucred *newcred, *oldcred;
1035 uid_t euid, ruid, suid;
1036 struct uidinfo *euip, *ruip;
1037 int error;
1038
1039 euid = uap->euid;
1040 ruid = uap->ruid;
1041 suid = uap->suid;
1042 AUDIT_ARG_EUID(euid);
1043 AUDIT_ARG_RUID(ruid);
1044 AUDIT_ARG_SUID(suid);
1045 newcred = crget();
1046 euip = uifind(euid);
1047 ruip = uifind(ruid);
1048 PROC_LOCK(p);
1049 oldcred = crcopysafe(p, newcred);
1050
1051 #ifdef MAC
1052 error = mac_cred_check_setresuid(oldcred, ruid, euid, suid);
1053 if (error)
1054 goto fail;
1055 #endif
1056
1057 if (((ruid != (uid_t)-1 && ruid != oldcred->cr_ruid &&
1058 ruid != oldcred->cr_svuid &&
1059 ruid != oldcred->cr_uid) ||
1060 (euid != (uid_t)-1 && euid != oldcred->cr_ruid &&
1061 euid != oldcred->cr_svuid &&
1062 euid != oldcred->cr_uid) ||
1063 (suid != (uid_t)-1 && suid != oldcred->cr_ruid &&
1064 suid != oldcred->cr_svuid &&
1065 suid != oldcred->cr_uid)) &&
1066 (error = priv_check_cred(oldcred, PRIV_CRED_SETRESUID, 0)) != 0)
1067 goto fail;
1068
1069 if (euid != (uid_t)-1 && oldcred->cr_uid != euid) {
1070 change_euid(newcred, euip);
1071 setsugid(p);
1072 }
1073 if (ruid != (uid_t)-1 && oldcred->cr_ruid != ruid) {
1074 change_ruid(newcred, ruip);
1075 setsugid(p);
1076 }
1077 if (suid != (uid_t)-1 && oldcred->cr_svuid != suid) {
1078 change_svuid(newcred, suid);
1079 setsugid(p);
1080 }
1081 proc_set_cred(p, newcred);
1082 #ifdef RACCT
1083 racct_proc_ucred_changed(p, oldcred, newcred);
1084 crhold(newcred);
1085 #endif
1086 PROC_UNLOCK(p);
1087 #ifdef RCTL
1088 rctl_proc_ucred_changed(p, newcred);
1089 crfree(newcred);
1090 #endif
1091 uifree(ruip);
1092 uifree(euip);
1093 crfree(oldcred);
1094 return (0);
1095
1096 fail:
1097 PROC_UNLOCK(p);
1098 uifree(ruip);
1099 uifree(euip);
1100 crfree(newcred);
1101 return (error);
1102
1103 }
1104
1105 /*
1106 * setresgid(rgid, egid, sgid) is like setregid except control over the saved
1107 * gid is explicit.
1108 */
1109 #ifndef _SYS_SYSPROTO_H_
1110 struct setresgid_args {
1111 gid_t rgid;
1112 gid_t egid;
1113 gid_t sgid;
1114 };
1115 #endif
1116 /* ARGSUSED */
1117 int
1118 sys_setresgid(struct thread *td, struct setresgid_args *uap)
1119 {
1120 struct proc *p = td->td_proc;
1121 struct ucred *newcred, *oldcred;
1122 gid_t egid, rgid, sgid;
1123 int error;
1124
1125 egid = uap->egid;
1126 rgid = uap->rgid;
1127 sgid = uap->sgid;
1128 AUDIT_ARG_EGID(egid);
1129 AUDIT_ARG_RGID(rgid);
1130 AUDIT_ARG_SGID(sgid);
1131 newcred = crget();
1132 PROC_LOCK(p);
1133 oldcred = crcopysafe(p, newcred);
1134
1135 #ifdef MAC
1136 error = mac_cred_check_setresgid(oldcred, rgid, egid, sgid);
1137 if (error)
1138 goto fail;
1139 #endif
1140
1141 if (((rgid != (gid_t)-1 && rgid != oldcred->cr_rgid &&
1142 rgid != oldcred->cr_svgid &&
1143 rgid != oldcred->cr_groups[0]) ||
1144 (egid != (gid_t)-1 && egid != oldcred->cr_rgid &&
1145 egid != oldcred->cr_svgid &&
1146 egid != oldcred->cr_groups[0]) ||
1147 (sgid != (gid_t)-1 && sgid != oldcred->cr_rgid &&
1148 sgid != oldcred->cr_svgid &&
1149 sgid != oldcred->cr_groups[0])) &&
1150 (error = priv_check_cred(oldcred, PRIV_CRED_SETRESGID, 0)) != 0)
1151 goto fail;
1152
1153 if (egid != (gid_t)-1 && oldcred->cr_groups[0] != egid) {
1154 change_egid(newcred, egid);
1155 setsugid(p);
1156 }
1157 if (rgid != (gid_t)-1 && oldcred->cr_rgid != rgid) {
1158 change_rgid(newcred, rgid);
1159 setsugid(p);
1160 }
1161 if (sgid != (gid_t)-1 && oldcred->cr_svgid != sgid) {
1162 change_svgid(newcred, sgid);
1163 setsugid(p);
1164 }
1165 proc_set_cred(p, newcred);
1166 PROC_UNLOCK(p);
1167 crfree(oldcred);
1168 return (0);
1169
1170 fail:
1171 PROC_UNLOCK(p);
1172 crfree(newcred);
1173 return (error);
1174 }
1175
1176 #ifndef _SYS_SYSPROTO_H_
1177 struct getresuid_args {
1178 uid_t *ruid;
1179 uid_t *euid;
1180 uid_t *suid;
1181 };
1182 #endif
1183 /* ARGSUSED */
1184 int
1185 sys_getresuid(struct thread *td, struct getresuid_args *uap)
1186 {
1187 struct ucred *cred;
1188 int error1 = 0, error2 = 0, error3 = 0;
1189
1190 cred = td->td_ucred;
1191 if (uap->ruid)
1192 error1 = copyout(&cred->cr_ruid,
1193 uap->ruid, sizeof(cred->cr_ruid));
1194 if (uap->euid)
1195 error2 = copyout(&cred->cr_uid,
1196 uap->euid, sizeof(cred->cr_uid));
1197 if (uap->suid)
1198 error3 = copyout(&cred->cr_svuid,
1199 uap->suid, sizeof(cred->cr_svuid));
1200 return (error1 ? error1 : error2 ? error2 : error3);
1201 }
1202
1203 #ifndef _SYS_SYSPROTO_H_
1204 struct getresgid_args {
1205 gid_t *rgid;
1206 gid_t *egid;
1207 gid_t *sgid;
1208 };
1209 #endif
1210 /* ARGSUSED */
1211 int
1212 sys_getresgid(struct thread *td, struct getresgid_args *uap)
1213 {
1214 struct ucred *cred;
1215 int error1 = 0, error2 = 0, error3 = 0;
1216
1217 cred = td->td_ucred;
1218 if (uap->rgid)
1219 error1 = copyout(&cred->cr_rgid,
1220 uap->rgid, sizeof(cred->cr_rgid));
1221 if (uap->egid)
1222 error2 = copyout(&cred->cr_groups[0],
1223 uap->egid, sizeof(cred->cr_groups[0]));
1224 if (uap->sgid)
1225 error3 = copyout(&cred->cr_svgid,
1226 uap->sgid, sizeof(cred->cr_svgid));
1227 return (error1 ? error1 : error2 ? error2 : error3);
1228 }
1229
1230 #ifndef _SYS_SYSPROTO_H_
1231 struct issetugid_args {
1232 int dummy;
1233 };
1234 #endif
1235 /* ARGSUSED */
1236 int
1237 sys_issetugid(struct thread *td, struct issetugid_args *uap)
1238 {
1239 struct proc *p = td->td_proc;
1240
1241 /*
1242 * Note: OpenBSD sets a P_SUGIDEXEC flag set at execve() time,
1243 * we use P_SUGID because we consider changing the owners as
1244 * "tainting" as well.
1245 * This is significant for procs that start as root and "become"
1246 * a user without an exec - programs cannot know *everything*
1247 * that libc *might* have put in their data segment.
1248 */
1249 td->td_retval[0] = (p->p_flag & P_SUGID) ? 1 : 0;
1250 return (0);
1251 }
1252
1253 int
1254 sys___setugid(struct thread *td, struct __setugid_args *uap)
1255 {
1256 #ifdef REGRESSION
1257 struct proc *p;
1258
1259 p = td->td_proc;
1260 switch (uap->flag) {
1261 case 0:
1262 PROC_LOCK(p);
1263 p->p_flag &= ~P_SUGID;
1264 PROC_UNLOCK(p);
1265 return (0);
1266 case 1:
1267 PROC_LOCK(p);
1268 p->p_flag |= P_SUGID;
1269 PROC_UNLOCK(p);
1270 return (0);
1271 default:
1272 return (EINVAL);
1273 }
1274 #else /* !REGRESSION */
1275
1276 return (ENOSYS);
1277 #endif /* REGRESSION */
1278 }
1279
1280 /*
1281 * Check if gid is a member of the group set.
1282 */
1283 int
1284 groupmember(gid_t gid, struct ucred *cred)
1285 {
1286 int l;
1287 int h;
1288 int m;
1289
1290 if (cred->cr_groups[0] == gid)
1291 return(1);
1292
1293 /*
1294 * If gid was not our primary group, perform a binary search
1295 * of the supplemental groups. This is possible because we
1296 * sort the groups in crsetgroups().
1297 */
1298 l = 1;
1299 h = cred->cr_ngroups;
1300 while (l < h) {
1301 m = l + ((h - l) / 2);
1302 if (cred->cr_groups[m] < gid)
1303 l = m + 1;
1304 else
1305 h = m;
1306 }
1307 if ((l < cred->cr_ngroups) && (cred->cr_groups[l] == gid))
1308 return (1);
1309
1310 return (0);
1311 }
1312
1313 /*
1314 * Test the active securelevel against a given level. securelevel_gt()
1315 * implements (securelevel > level). securelevel_ge() implements
1316 * (securelevel >= level). Note that the logic is inverted -- these
1317 * functions return EPERM on "success" and 0 on "failure".
1318 *
1319 * Due to care taken when setting the securelevel, we know that no jail will
1320 * be less secure that its parent (or the physical system), so it is sufficient
1321 * to test the current jail only.
1322 *
1323 * XXXRW: Possibly since this has to do with privilege, it should move to
1324 * kern_priv.c.
1325 */
1326 int
1327 securelevel_gt(struct ucred *cr, int level)
1328 {
1329
1330 return (cr->cr_prison->pr_securelevel > level ? EPERM : 0);
1331 }
1332
1333 int
1334 securelevel_ge(struct ucred *cr, int level)
1335 {
1336
1337 return (cr->cr_prison->pr_securelevel >= level ? EPERM : 0);
1338 }
1339
1340 /*
1341 * 'see_other_uids' determines whether or not visibility of processes
1342 * and sockets with credentials holding different real uids is possible
1343 * using a variety of system MIBs.
1344 * XXX: data declarations should be together near the beginning of the file.
1345 */
1346 static int see_other_uids = 1;
1347 SYSCTL_INT(_security_bsd, OID_AUTO, see_other_uids, CTLFLAG_RW,
1348 &see_other_uids, 0,
1349 "Unprivileged processes may see subjects/objects with different real uid");
1350
1351 /*-
1352 * Determine if u1 "can see" the subject specified by u2, according to the
1353 * 'see_other_uids' policy.
1354 * Returns: 0 for permitted, ESRCH otherwise
1355 * Locks: none
1356 * References: *u1 and *u2 must not change during the call
1357 * u1 may equal u2, in which case only one reference is required
1358 */
1359 static int
1360 cr_seeotheruids(struct ucred *u1, struct ucred *u2)
1361 {
1362
1363 if (!see_other_uids && u1->cr_ruid != u2->cr_ruid) {
1364 if (priv_check_cred(u1, PRIV_SEEOTHERUIDS, 0) != 0)
1365 return (ESRCH);
1366 }
1367 return (0);
1368 }
1369
1370 /*
1371 * 'see_other_gids' determines whether or not visibility of processes
1372 * and sockets with credentials holding different real gids is possible
1373 * using a variety of system MIBs.
1374 * XXX: data declarations should be together near the beginning of the file.
1375 */
1376 static int see_other_gids = 1;
1377 SYSCTL_INT(_security_bsd, OID_AUTO, see_other_gids, CTLFLAG_RW,
1378 &see_other_gids, 0,
1379 "Unprivileged processes may see subjects/objects with different real gid");
1380
1381 /*
1382 * Determine if u1 can "see" the subject specified by u2, according to the
1383 * 'see_other_gids' policy.
1384 * Returns: 0 for permitted, ESRCH otherwise
1385 * Locks: none
1386 * References: *u1 and *u2 must not change during the call
1387 * u1 may equal u2, in which case only one reference is required
1388 */
1389 static int
1390 cr_seeothergids(struct ucred *u1, struct ucred *u2)
1391 {
1392 int i, match;
1393
1394 if (!see_other_gids) {
1395 match = 0;
1396 for (i = 0; i < u1->cr_ngroups; i++) {
1397 if (groupmember(u1->cr_groups[i], u2))
1398 match = 1;
1399 if (match)
1400 break;
1401 }
1402 if (!match) {
1403 if (priv_check_cred(u1, PRIV_SEEOTHERGIDS, 0) != 0)
1404 return (ESRCH);
1405 }
1406 }
1407 return (0);
1408 }
1409
1410 /*-
1411 * Determine if u1 "can see" the subject specified by u2.
1412 * Returns: 0 for permitted, an errno value otherwise
1413 * Locks: none
1414 * References: *u1 and *u2 must not change during the call
1415 * u1 may equal u2, in which case only one reference is required
1416 */
1417 int
1418 cr_cansee(struct ucred *u1, struct ucred *u2)
1419 {
1420 int error;
1421
1422 if ((error = prison_check(u1, u2)))
1423 return (error);
1424 #ifdef MAC
1425 if ((error = mac_cred_check_visible(u1, u2)))
1426 return (error);
1427 #endif
1428 if ((error = cr_seeotheruids(u1, u2)))
1429 return (error);
1430 if ((error = cr_seeothergids(u1, u2)))
1431 return (error);
1432 return (0);
1433 }
1434
1435 /*-
1436 * Determine if td "can see" the subject specified by p.
1437 * Returns: 0 for permitted, an errno value otherwise
1438 * Locks: Sufficient locks to protect p->p_ucred must be held. td really
1439 * should be curthread.
1440 * References: td and p must be valid for the lifetime of the call
1441 */
1442 int
1443 p_cansee(struct thread *td, struct proc *p)
1444 {
1445
1446 /* Wrap cr_cansee() for all functionality. */
1447 KASSERT(td == curthread, ("%s: td not curthread", __func__));
1448 PROC_LOCK_ASSERT(p, MA_OWNED);
1449 return (cr_cansee(td->td_ucred, p->p_ucred));
1450 }
1451
1452 /*
1453 * 'conservative_signals' prevents the delivery of a broad class of
1454 * signals by unprivileged processes to processes that have changed their
1455 * credentials since the last invocation of execve(). This can prevent
1456 * the leakage of cached information or retained privileges as a result
1457 * of a common class of signal-related vulnerabilities. However, this
1458 * may interfere with some applications that expect to be able to
1459 * deliver these signals to peer processes after having given up
1460 * privilege.
1461 */
1462 static int conservative_signals = 1;
1463 SYSCTL_INT(_security_bsd, OID_AUTO, conservative_signals, CTLFLAG_RW,
1464 &conservative_signals, 0, "Unprivileged processes prevented from "
1465 "sending certain signals to processes whose credentials have changed");
1466 /*-
1467 * Determine whether cred may deliver the specified signal to proc.
1468 * Returns: 0 for permitted, an errno value otherwise.
1469 * Locks: A lock must be held for proc.
1470 * References: cred and proc must be valid for the lifetime of the call.
1471 */
1472 int
1473 cr_cansignal(struct ucred *cred, struct proc *proc, int signum)
1474 {
1475 int error;
1476
1477 PROC_LOCK_ASSERT(proc, MA_OWNED);
1478 /*
1479 * Jail semantics limit the scope of signalling to proc in the
1480 * same jail as cred, if cred is in jail.
1481 */
1482 error = prison_check(cred, proc->p_ucred);
1483 if (error)
1484 return (error);
1485 #ifdef MAC
1486 if ((error = mac_proc_check_signal(cred, proc, signum)))
1487 return (error);
1488 #endif
1489 if ((error = cr_seeotheruids(cred, proc->p_ucred)))
1490 return (error);
1491 if ((error = cr_seeothergids(cred, proc->p_ucred)))
1492 return (error);
1493
1494 /*
1495 * UNIX signal semantics depend on the status of the P_SUGID
1496 * bit on the target process. If the bit is set, then additional
1497 * restrictions are placed on the set of available signals.
1498 */
1499 if (conservative_signals && (proc->p_flag & P_SUGID)) {
1500 switch (signum) {
1501 case 0:
1502 case SIGKILL:
1503 case SIGINT:
1504 case SIGTERM:
1505 case SIGALRM:
1506 case SIGSTOP:
1507 case SIGTTIN:
1508 case SIGTTOU:
1509 case SIGTSTP:
1510 case SIGHUP:
1511 case SIGUSR1:
1512 case SIGUSR2:
1513 /*
1514 * Generally, permit job and terminal control
1515 * signals.
1516 */
1517 break;
1518 default:
1519 /* Not permitted without privilege. */
1520 error = priv_check_cred(cred, PRIV_SIGNAL_SUGID, 0);
1521 if (error)
1522 return (error);
1523 }
1524 }
1525
1526 /*
1527 * Generally, the target credential's ruid or svuid must match the
1528 * subject credential's ruid or euid.
1529 */
1530 if (cred->cr_ruid != proc->p_ucred->cr_ruid &&
1531 cred->cr_ruid != proc->p_ucred->cr_svuid &&
1532 cred->cr_uid != proc->p_ucred->cr_ruid &&
1533 cred->cr_uid != proc->p_ucred->cr_svuid) {
1534 error = priv_check_cred(cred, PRIV_SIGNAL_DIFFCRED, 0);
1535 if (error)
1536 return (error);
1537 }
1538
1539 return (0);
1540 }
1541
1542 /*-
1543 * Determine whether td may deliver the specified signal to p.
1544 * Returns: 0 for permitted, an errno value otherwise
1545 * Locks: Sufficient locks to protect various components of td and p
1546 * must be held. td must be curthread, and a lock must be
1547 * held for p.
1548 * References: td and p must be valid for the lifetime of the call
1549 */
1550 int
1551 p_cansignal(struct thread *td, struct proc *p, int signum)
1552 {
1553
1554 KASSERT(td == curthread, ("%s: td not curthread", __func__));
1555 PROC_LOCK_ASSERT(p, MA_OWNED);
1556 if (td->td_proc == p)
1557 return (0);
1558
1559 /*
1560 * UNIX signalling semantics require that processes in the same
1561 * session always be able to deliver SIGCONT to one another,
1562 * overriding the remaining protections.
1563 */
1564 /* XXX: This will require an additional lock of some sort. */
1565 if (signum == SIGCONT && td->td_proc->p_session == p->p_session)
1566 return (0);
1567 /*
1568 * Some compat layers use SIGTHR and higher signals for
1569 * communication between different kernel threads of the same
1570 * process, so that they expect that it's always possible to
1571 * deliver them, even for suid applications where cr_cansignal() can
1572 * deny such ability for security consideration. It should be
1573 * pretty safe to do since the only way to create two processes
1574 * with the same p_leader is via rfork(2).
1575 */
1576 if (td->td_proc->p_leader != NULL && signum >= SIGTHR &&
1577 signum < SIGTHR + 4 && td->td_proc->p_leader == p->p_leader)
1578 return (0);
1579
1580 return (cr_cansignal(td->td_ucred, p, signum));
1581 }
1582
1583 /*-
1584 * Determine whether td may reschedule p.
1585 * Returns: 0 for permitted, an errno value otherwise
1586 * Locks: Sufficient locks to protect various components of td and p
1587 * must be held. td must be curthread, and a lock must
1588 * be held for p.
1589 * References: td and p must be valid for the lifetime of the call
1590 */
1591 int
1592 p_cansched(struct thread *td, struct proc *p)
1593 {
1594 int error;
1595
1596 KASSERT(td == curthread, ("%s: td not curthread", __func__));
1597 PROC_LOCK_ASSERT(p, MA_OWNED);
1598 if (td->td_proc == p)
1599 return (0);
1600 if ((error = prison_check(td->td_ucred, p->p_ucred)))
1601 return (error);
1602 #ifdef MAC
1603 if ((error = mac_proc_check_sched(td->td_ucred, p)))
1604 return (error);
1605 #endif
1606 if ((error = cr_seeotheruids(td->td_ucred, p->p_ucred)))
1607 return (error);
1608 if ((error = cr_seeothergids(td->td_ucred, p->p_ucred)))
1609 return (error);
1610 if (td->td_ucred->cr_ruid != p->p_ucred->cr_ruid &&
1611 td->td_ucred->cr_uid != p->p_ucred->cr_ruid) {
1612 error = priv_check(td, PRIV_SCHED_DIFFCRED);
1613 if (error)
1614 return (error);
1615 }
1616 return (0);
1617 }
1618
1619 /*
1620 * The 'unprivileged_proc_debug' flag may be used to disable a variety of
1621 * unprivileged inter-process debugging services, including some procfs
1622 * functionality, ptrace(), and ktrace(). In the past, inter-process
1623 * debugging has been involved in a variety of security problems, and sites
1624 * not requiring the service might choose to disable it when hardening
1625 * systems.
1626 *
1627 * XXX: Should modifying and reading this variable require locking?
1628 * XXX: data declarations should be together near the beginning of the file.
1629 */
1630 static int unprivileged_proc_debug = 1;
1631 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_proc_debug, CTLFLAG_RW,
1632 &unprivileged_proc_debug, 0,
1633 "Unprivileged processes may use process debugging facilities");
1634
1635 /*-
1636 * Determine whether td may debug p.
1637 * Returns: 0 for permitted, an errno value otherwise
1638 * Locks: Sufficient locks to protect various components of td and p
1639 * must be held. td must be curthread, and a lock must
1640 * be held for p.
1641 * References: td and p must be valid for the lifetime of the call
1642 */
1643 int
1644 p_candebug(struct thread *td, struct proc *p)
1645 {
1646 int credentialchanged, error, grpsubset, i, uidsubset;
1647
1648 KASSERT(td == curthread, ("%s: td not curthread", __func__));
1649 PROC_LOCK_ASSERT(p, MA_OWNED);
1650 if (!unprivileged_proc_debug) {
1651 error = priv_check(td, PRIV_DEBUG_UNPRIV);
1652 if (error)
1653 return (error);
1654 }
1655 if (td->td_proc == p)
1656 return (0);
1657 if ((error = prison_check(td->td_ucred, p->p_ucred)))
1658 return (error);
1659 #ifdef MAC
1660 if ((error = mac_proc_check_debug(td->td_ucred, p)))
1661 return (error);
1662 #endif
1663 if ((error = cr_seeotheruids(td->td_ucred, p->p_ucred)))
1664 return (error);
1665 if ((error = cr_seeothergids(td->td_ucred, p->p_ucred)))
1666 return (error);
1667
1668 /*
1669 * Is p's group set a subset of td's effective group set? This
1670 * includes p's egid, group access list, rgid, and svgid.
1671 */
1672 grpsubset = 1;
1673 for (i = 0; i < p->p_ucred->cr_ngroups; i++) {
1674 if (!groupmember(p->p_ucred->cr_groups[i], td->td_ucred)) {
1675 grpsubset = 0;
1676 break;
1677 }
1678 }
1679 grpsubset = grpsubset &&
1680 groupmember(p->p_ucred->cr_rgid, td->td_ucred) &&
1681 groupmember(p->p_ucred->cr_svgid, td->td_ucred);
1682
1683 /*
1684 * Are the uids present in p's credential equal to td's
1685 * effective uid? This includes p's euid, svuid, and ruid.
1686 */
1687 uidsubset = (td->td_ucred->cr_uid == p->p_ucred->cr_uid &&
1688 td->td_ucred->cr_uid == p->p_ucred->cr_svuid &&
1689 td->td_ucred->cr_uid == p->p_ucred->cr_ruid);
1690
1691 /*
1692 * Has the credential of the process changed since the last exec()?
1693 */
1694 credentialchanged = (p->p_flag & P_SUGID);
1695
1696 /*
1697 * If p's gids aren't a subset, or the uids aren't a subset,
1698 * or the credential has changed, require appropriate privilege
1699 * for td to debug p.
1700 */
1701 if (!grpsubset || !uidsubset) {
1702 error = priv_check(td, PRIV_DEBUG_DIFFCRED);
1703 if (error)
1704 return (error);
1705 }
1706
1707 if (credentialchanged) {
1708 error = priv_check(td, PRIV_DEBUG_SUGID);
1709 if (error)
1710 return (error);
1711 }
1712
1713 /* Can't trace init when securelevel > 0. */
1714 if (p == initproc) {
1715 error = securelevel_gt(td->td_ucred, 0);
1716 if (error)
1717 return (error);
1718 }
1719
1720 /*
1721 * Can't trace a process that's currently exec'ing.
1722 *
1723 * XXX: Note, this is not a security policy decision, it's a
1724 * basic correctness/functionality decision. Therefore, this check
1725 * should be moved to the caller's of p_candebug().
1726 */
1727 if ((p->p_flag & P_INEXEC) != 0)
1728 return (EBUSY);
1729
1730 /* Denied explicitely */
1731 if ((p->p_flag2 & P2_NOTRACE) != 0) {
1732 error = priv_check(td, PRIV_DEBUG_DENIED);
1733 if (error != 0)
1734 return (error);
1735 }
1736
1737 return (0);
1738 }
1739
1740 /*-
1741 * Determine whether the subject represented by cred can "see" a socket.
1742 * Returns: 0 for permitted, ENOENT otherwise.
1743 */
1744 int
1745 cr_canseesocket(struct ucred *cred, struct socket *so)
1746 {
1747 int error;
1748
1749 error = prison_check(cred, so->so_cred);
1750 if (error)
1751 return (ENOENT);
1752 #ifdef MAC
1753 error = mac_socket_check_visible(cred, so);
1754 if (error)
1755 return (error);
1756 #endif
1757 if (cr_seeotheruids(cred, so->so_cred))
1758 return (ENOENT);
1759 if (cr_seeothergids(cred, so->so_cred))
1760 return (ENOENT);
1761
1762 return (0);
1763 }
1764
1765 #if defined(INET) || defined(INET6)
1766 /*-
1767 * Determine whether the subject represented by cred can "see" a socket.
1768 * Returns: 0 for permitted, ENOENT otherwise.
1769 */
1770 int
1771 cr_canseeinpcb(struct ucred *cred, struct inpcb *inp)
1772 {
1773 int error;
1774
1775 error = prison_check(cred, inp->inp_cred);
1776 if (error)
1777 return (ENOENT);
1778 #ifdef MAC
1779 INP_LOCK_ASSERT(inp);
1780 error = mac_inpcb_check_visible(cred, inp);
1781 if (error)
1782 return (error);
1783 #endif
1784 if (cr_seeotheruids(cred, inp->inp_cred))
1785 return (ENOENT);
1786 if (cr_seeothergids(cred, inp->inp_cred))
1787 return (ENOENT);
1788
1789 return (0);
1790 }
1791 #endif
1792
1793 /*-
1794 * Determine whether td can wait for the exit of p.
1795 * Returns: 0 for permitted, an errno value otherwise
1796 * Locks: Sufficient locks to protect various components of td and p
1797 * must be held. td must be curthread, and a lock must
1798 * be held for p.
1799 * References: td and p must be valid for the lifetime of the call
1800
1801 */
1802 int
1803 p_canwait(struct thread *td, struct proc *p)
1804 {
1805 int error;
1806
1807 KASSERT(td == curthread, ("%s: td not curthread", __func__));
1808 PROC_LOCK_ASSERT(p, MA_OWNED);
1809 if ((error = prison_check(td->td_ucred, p->p_ucred)))
1810 return (error);
1811 #ifdef MAC
1812 if ((error = mac_proc_check_wait(td->td_ucred, p)))
1813 return (error);
1814 #endif
1815 #if 0
1816 /* XXXMAC: This could have odd effects on some shells. */
1817 if ((error = cr_seeotheruids(td->td_ucred, p->p_ucred)))
1818 return (error);
1819 #endif
1820
1821 return (0);
1822 }
1823
1824 /*
1825 * Allocate a zeroed cred structure.
1826 */
1827 struct ucred *
1828 crget(void)
1829 {
1830 struct ucred *cr;
1831
1832 cr = malloc(sizeof(*cr), M_CRED, M_WAITOK | M_ZERO);
1833 refcount_init(&cr->cr_ref, 1);
1834 #ifdef AUDIT
1835 audit_cred_init(cr);
1836 #endif
1837 #ifdef MAC
1838 mac_cred_init(cr);
1839 #endif
1840 cr->cr_groups = cr->cr_smallgroups;
1841 cr->cr_agroups =
1842 sizeof(cr->cr_smallgroups) / sizeof(cr->cr_smallgroups[0]);
1843 return (cr);
1844 }
1845
1846 /*
1847 * Claim another reference to a ucred structure.
1848 */
1849 struct ucred *
1850 crhold(struct ucred *cr)
1851 {
1852
1853 refcount_acquire(&cr->cr_ref);
1854 return (cr);
1855 }
1856
1857 /*
1858 * Free a cred structure. Throws away space when ref count gets to 0.
1859 */
1860 void
1861 crfree(struct ucred *cr)
1862 {
1863
1864 KASSERT(cr->cr_ref > 0, ("bad ucred refcount: %d", cr->cr_ref));
1865 KASSERT(cr->cr_ref != 0xdeadc0de, ("dangling reference to ucred"));
1866 if (refcount_release(&cr->cr_ref)) {
1867 /*
1868 * Some callers of crget(), such as nfs_statfs(),
1869 * allocate a temporary credential, but don't
1870 * allocate a uidinfo structure.
1871 */
1872 if (cr->cr_uidinfo != NULL)
1873 uifree(cr->cr_uidinfo);
1874 if (cr->cr_ruidinfo != NULL)
1875 uifree(cr->cr_ruidinfo);
1876 /*
1877 * Free a prison, if any.
1878 */
1879 if (cr->cr_prison != NULL)
1880 prison_free(cr->cr_prison);
1881 if (cr->cr_loginclass != NULL)
1882 loginclass_free(cr->cr_loginclass);
1883 #ifdef AUDIT
1884 audit_cred_destroy(cr);
1885 #endif
1886 #ifdef MAC
1887 mac_cred_destroy(cr);
1888 #endif
1889 if (cr->cr_groups != cr->cr_smallgroups)
1890 free(cr->cr_groups, M_CRED);
1891 free(cr, M_CRED);
1892 }
1893 }
1894
1895 /*
1896 * Copy a ucred's contents from a template. Does not block.
1897 */
1898 void
1899 crcopy(struct ucred *dest, struct ucred *src)
1900 {
1901
1902 KASSERT(dest->cr_ref == 1, ("crcopy of shared ucred"));
1903 bcopy(&src->cr_startcopy, &dest->cr_startcopy,
1904 (unsigned)((caddr_t)&src->cr_endcopy -
1905 (caddr_t)&src->cr_startcopy));
1906 crsetgroups(dest, src->cr_ngroups, src->cr_groups);
1907 uihold(dest->cr_uidinfo);
1908 uihold(dest->cr_ruidinfo);
1909 prison_hold(dest->cr_prison);
1910 loginclass_hold(dest->cr_loginclass);
1911 #ifdef AUDIT
1912 audit_cred_copy(src, dest);
1913 #endif
1914 #ifdef MAC
1915 mac_cred_copy(src, dest);
1916 #endif
1917 }
1918
1919 /*
1920 * Dup cred struct to a new held one.
1921 */
1922 struct ucred *
1923 crdup(struct ucred *cr)
1924 {
1925 struct ucred *newcr;
1926
1927 newcr = crget();
1928 crcopy(newcr, cr);
1929 return (newcr);
1930 }
1931
1932 /*
1933 * Fill in a struct xucred based on a struct ucred.
1934 */
1935 void
1936 cru2x(struct ucred *cr, struct xucred *xcr)
1937 {
1938 int ngroups;
1939
1940 bzero(xcr, sizeof(*xcr));
1941 xcr->cr_version = XUCRED_VERSION;
1942 xcr->cr_uid = cr->cr_uid;
1943
1944 ngroups = MIN(cr->cr_ngroups, XU_NGROUPS);
1945 xcr->cr_ngroups = ngroups;
1946 bcopy(cr->cr_groups, xcr->cr_groups,
1947 ngroups * sizeof(*cr->cr_groups));
1948 }
1949
1950 /*
1951 * Set initial process credentials.
1952 * Callers are responsible for providing the reference for provided credentials.
1953 */
1954 void
1955 proc_set_cred_init(struct proc *p, struct ucred *newcred)
1956 {
1957
1958 p->p_ucred = newcred;
1959 }
1960
1961 /*
1962 * Change process credentials.
1963 * Callers are responsible for providing the reference for passed credentials
1964 * and for freeing old ones.
1965 *
1966 * Process has to be locked except when it does not have credentials (as it
1967 * should not be visible just yet) or when newcred is NULL (as this can be
1968 * only used when the process is about to be freed, at which point it should
1969 * not be visible anymore).
1970 */
1971 struct ucred *
1972 proc_set_cred(struct proc *p, struct ucred *newcred)
1973 {
1974 struct ucred *oldcred;
1975
1976 MPASS(p->p_ucred != NULL);
1977 if (newcred == NULL)
1978 MPASS(p->p_state == PRS_ZOMBIE);
1979 else
1980 PROC_LOCK_ASSERT(p, MA_OWNED);
1981
1982 oldcred = p->p_ucred;
1983 p->p_ucred = newcred;
1984 if (newcred != NULL)
1985 PROC_UPDATE_COW(p);
1986 return (oldcred);
1987 }
1988
1989 struct ucred *
1990 crcopysafe(struct proc *p, struct ucred *cr)
1991 {
1992 struct ucred *oldcred;
1993 int groups;
1994
1995 PROC_LOCK_ASSERT(p, MA_OWNED);
1996
1997 oldcred = p->p_ucred;
1998 while (cr->cr_agroups < oldcred->cr_agroups) {
1999 groups = oldcred->cr_agroups;
2000 PROC_UNLOCK(p);
2001 crextend(cr, groups);
2002 PROC_LOCK(p);
2003 oldcred = p->p_ucred;
2004 }
2005 crcopy(cr, oldcred);
2006
2007 return (oldcred);
2008 }
2009
2010 /*
2011 * Extend the passed in credential to hold n items.
2012 */
2013 void
2014 crextend(struct ucred *cr, int n)
2015 {
2016 int cnt;
2017
2018 /* Truncate? */
2019 if (n <= cr->cr_agroups)
2020 return;
2021
2022 /*
2023 * We extend by 2 each time since we're using a power of two
2024 * allocator until we need enough groups to fill a page.
2025 * Once we're allocating multiple pages, only allocate as many
2026 * as we actually need. The case of processes needing a
2027 * non-power of two number of pages seems more likely than
2028 * a real world process that adds thousands of groups one at a
2029 * time.
2030 */
2031 if ( n < PAGE_SIZE / sizeof(gid_t) ) {
2032 if (cr->cr_agroups == 0)
2033 cnt = MINALLOCSIZE / sizeof(gid_t);
2034 else
2035 cnt = cr->cr_agroups * 2;
2036
2037 while (cnt < n)
2038 cnt *= 2;
2039 } else
2040 cnt = roundup2(n, PAGE_SIZE / sizeof(gid_t));
2041
2042 /* Free the old array. */
2043 if (cr->cr_groups != cr->cr_smallgroups)
2044 free(cr->cr_groups, M_CRED);
2045
2046 cr->cr_groups = malloc(cnt * sizeof(gid_t), M_CRED, M_WAITOK | M_ZERO);
2047 cr->cr_agroups = cnt;
2048 }
2049
2050 /*
2051 * Copy groups in to a credential, preserving any necessary invariants.
2052 * Currently this includes the sorting of all supplemental gids.
2053 * crextend() must have been called before hand to ensure sufficient
2054 * space is available.
2055 */
2056 static void
2057 crsetgroups_locked(struct ucred *cr, int ngrp, gid_t *groups)
2058 {
2059 int i;
2060 int j;
2061 gid_t g;
2062
2063 KASSERT(cr->cr_agroups >= ngrp, ("cr_ngroups is too small"));
2064
2065 bcopy(groups, cr->cr_groups, ngrp * sizeof(gid_t));
2066 cr->cr_ngroups = ngrp;
2067
2068 /*
2069 * Sort all groups except cr_groups[0] to allow groupmember to
2070 * perform a binary search.
2071 *
2072 * XXX: If large numbers of groups become common this should
2073 * be replaced with shell sort like linux uses or possibly
2074 * heap sort.
2075 */
2076 for (i = 2; i < ngrp; i++) {
2077 g = cr->cr_groups[i];
2078 for (j = i-1; j >= 1 && g < cr->cr_groups[j]; j--)
2079 cr->cr_groups[j + 1] = cr->cr_groups[j];
2080 cr->cr_groups[j + 1] = g;
2081 }
2082 }
2083
2084 /*
2085 * Copy groups in to a credential after expanding it if required.
2086 * Truncate the list to (ngroups_max + 1) if it is too large.
2087 */
2088 void
2089 crsetgroups(struct ucred *cr, int ngrp, gid_t *groups)
2090 {
2091
2092 if (ngrp > ngroups_max + 1)
2093 ngrp = ngroups_max + 1;
2094
2095 crextend(cr, ngrp);
2096 crsetgroups_locked(cr, ngrp, groups);
2097 }
2098
2099 /*
2100 * Get login name, if available.
2101 */
2102 #ifndef _SYS_SYSPROTO_H_
2103 struct getlogin_args {
2104 char *namebuf;
2105 u_int namelen;
2106 };
2107 #endif
2108 /* ARGSUSED */
2109 int
2110 sys_getlogin(struct thread *td, struct getlogin_args *uap)
2111 {
2112 char login[MAXLOGNAME];
2113 struct proc *p = td->td_proc;
2114 size_t len;
2115
2116 if (uap->namelen > MAXLOGNAME)
2117 uap->namelen = MAXLOGNAME;
2118 PROC_LOCK(p);
2119 SESS_LOCK(p->p_session);
2120 len = strlcpy(login, p->p_session->s_login, uap->namelen) + 1;
2121 SESS_UNLOCK(p->p_session);
2122 PROC_UNLOCK(p);
2123 if (len > uap->namelen)
2124 return (ERANGE);
2125 return (copyout(login, uap->namebuf, len));
2126 }
2127
2128 /*
2129 * Set login name.
2130 */
2131 #ifndef _SYS_SYSPROTO_H_
2132 struct setlogin_args {
2133 char *namebuf;
2134 };
2135 #endif
2136 /* ARGSUSED */
2137 int
2138 sys_setlogin(struct thread *td, struct setlogin_args *uap)
2139 {
2140 struct proc *p = td->td_proc;
2141 int error;
2142 char logintmp[MAXLOGNAME];
2143
2144 CTASSERT(sizeof(p->p_session->s_login) >= sizeof(logintmp));
2145
2146 error = priv_check(td, PRIV_PROC_SETLOGIN);
2147 if (error)
2148 return (error);
2149 error = copyinstr(uap->namebuf, logintmp, sizeof(logintmp), NULL);
2150 if (error != 0) {
2151 if (error == ENAMETOOLONG)
2152 error = EINVAL;
2153 return (error);
2154 }
2155 PROC_LOCK(p);
2156 SESS_LOCK(p->p_session);
2157 strcpy(p->p_session->s_login, logintmp);
2158 SESS_UNLOCK(p->p_session);
2159 PROC_UNLOCK(p);
2160 return (0);
2161 }
2162
2163 void
2164 setsugid(struct proc *p)
2165 {
2166
2167 PROC_LOCK_ASSERT(p, MA_OWNED);
2168 p->p_flag |= P_SUGID;
2169 if (!(p->p_pfsflags & PF_ISUGID))
2170 p->p_stops = 0;
2171 }
2172
2173 /*-
2174 * Change a process's effective uid.
2175 * Side effects: newcred->cr_uid and newcred->cr_uidinfo will be modified.
2176 * References: newcred must be an exclusive credential reference for the
2177 * duration of the call.
2178 */
2179 void
2180 change_euid(struct ucred *newcred, struct uidinfo *euip)
2181 {
2182
2183 newcred->cr_uid = euip->ui_uid;
2184 uihold(euip);
2185 uifree(newcred->cr_uidinfo);
2186 newcred->cr_uidinfo = euip;
2187 }
2188
2189 /*-
2190 * Change a process's effective gid.
2191 * Side effects: newcred->cr_gid will be modified.
2192 * References: newcred must be an exclusive credential reference for the
2193 * duration of the call.
2194 */
2195 void
2196 change_egid(struct ucred *newcred, gid_t egid)
2197 {
2198
2199 newcred->cr_groups[0] = egid;
2200 }
2201
2202 /*-
2203 * Change a process's real uid.
2204 * Side effects: newcred->cr_ruid will be updated, newcred->cr_ruidinfo
2205 * will be updated, and the old and new cr_ruidinfo proc
2206 * counts will be updated.
2207 * References: newcred must be an exclusive credential reference for the
2208 * duration of the call.
2209 */
2210 void
2211 change_ruid(struct ucred *newcred, struct uidinfo *ruip)
2212 {
2213
2214 (void)chgproccnt(newcred->cr_ruidinfo, -1, 0);
2215 newcred->cr_ruid = ruip->ui_uid;
2216 uihold(ruip);
2217 uifree(newcred->cr_ruidinfo);
2218 newcred->cr_ruidinfo = ruip;
2219 (void)chgproccnt(newcred->cr_ruidinfo, 1, 0);
2220 }
2221
2222 /*-
2223 * Change a process's real gid.
2224 * Side effects: newcred->cr_rgid will be updated.
2225 * References: newcred must be an exclusive credential reference for the
2226 * duration of the call.
2227 */
2228 void
2229 change_rgid(struct ucred *newcred, gid_t rgid)
2230 {
2231
2232 newcred->cr_rgid = rgid;
2233 }
2234
2235 /*-
2236 * Change a process's saved uid.
2237 * Side effects: newcred->cr_svuid will be updated.
2238 * References: newcred must be an exclusive credential reference for the
2239 * duration of the call.
2240 */
2241 void
2242 change_svuid(struct ucred *newcred, uid_t svuid)
2243 {
2244
2245 newcred->cr_svuid = svuid;
2246 }
2247
2248 /*-
2249 * Change a process's saved gid.
2250 * Side effects: newcred->cr_svgid will be updated.
2251 * References: newcred must be an exclusive credential reference for the
2252 * duration of the call.
2253 */
2254 void
2255 change_svgid(struct ucred *newcred, gid_t svgid)
2256 {
2257
2258 newcred->cr_svgid = svgid;
2259 }
Cache object: 19fb5aa455cfc679fd347d7eaf54591e
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