kern_prot.c revision 277698
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: stable/10/sys/kern/kern_prot.c 277698 2015-01-25 13:15:12Z kib $"); 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/resourcevar.h> 69#include <sys/socket.h> 70#include <sys/socketvar.h> 71#include <sys/syscallsubr.h> 72#include <sys/sysctl.h> 73 74#ifdef REGRESSION 75FEATURE(regression, 76 "Kernel support for interfaces necessary for regression testing (SECURITY RISK!)"); 77#endif 78 79#if defined(INET) || defined(INET6) 80#include <netinet/in.h> 81#include <netinet/in_pcb.h> 82#endif 83 84#include <security/audit/audit.h> 85#include <security/mac/mac_framework.h> 86 87static MALLOC_DEFINE(M_CRED, "cred", "credentials"); 88 89SYSCTL_NODE(_security, OID_AUTO, bsd, CTLFLAG_RW, 0, "BSD security policy"); 90 91static void crextend(struct ucred *cr, int n); 92static void crsetgroups_locked(struct ucred *cr, int ngrp, 93 gid_t *groups); 94 95#ifndef _SYS_SYSPROTO_H_ 96struct getpid_args { 97 int dummy; 98}; 99#endif 100/* ARGSUSED */ 101int 102sys_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 PROC_LOCK(p); 109 td->td_retval[1] = p->p_pptr->p_pid; 110 PROC_UNLOCK(p); 111#endif 112 return (0); 113} 114 115#ifndef _SYS_SYSPROTO_H_ 116struct getppid_args { 117 int dummy; 118}; 119#endif 120/* ARGSUSED */ 121int 122sys_getppid(struct thread *td, struct getppid_args *uap) 123{ 124 struct proc *p = td->td_proc; 125 126 PROC_LOCK(p); 127 td->td_retval[0] = p->p_pptr->p_pid; 128 PROC_UNLOCK(p); 129 return (0); 130} 131 132/* 133 * Get process group ID; note that POSIX getpgrp takes no parameter. 134 */ 135#ifndef _SYS_SYSPROTO_H_ 136struct getpgrp_args { 137 int dummy; 138}; 139#endif 140int 141sys_getpgrp(struct thread *td, struct getpgrp_args *uap) 142{ 143 struct proc *p = td->td_proc; 144 145 PROC_LOCK(p); 146 td->td_retval[0] = p->p_pgrp->pg_id; 147 PROC_UNLOCK(p); 148 return (0); 149} 150 151/* Get an arbitary pid's process group id */ 152#ifndef _SYS_SYSPROTO_H_ 153struct getpgid_args { 154 pid_t pid; 155}; 156#endif 157int 158sys_getpgid(struct thread *td, struct getpgid_args *uap) 159{ 160 struct proc *p; 161 int error; 162 163 if (uap->pid == 0) { 164 p = td->td_proc; 165 PROC_LOCK(p); 166 } else { 167 p = pfind(uap->pid); 168 if (p == NULL) 169 return (ESRCH); 170 error = p_cansee(td, p); 171 if (error) { 172 PROC_UNLOCK(p); 173 return (error); 174 } 175 } 176 td->td_retval[0] = p->p_pgrp->pg_id; 177 PROC_UNLOCK(p); 178 return (0); 179} 180 181/* 182 * Get an arbitary pid's session id. 183 */ 184#ifndef _SYS_SYSPROTO_H_ 185struct getsid_args { 186 pid_t pid; 187}; 188#endif 189int 190sys_getsid(struct thread *td, struct getsid_args *uap) 191{ 192 struct proc *p; 193 int error; 194 195 if (uap->pid == 0) { 196 p = td->td_proc; 197 PROC_LOCK(p); 198 } else { 199 p = pfind(uap->pid); 200 if (p == NULL) 201 return (ESRCH); 202 error = p_cansee(td, p); 203 if (error) { 204 PROC_UNLOCK(p); 205 return (error); 206 } 207 } 208 td->td_retval[0] = p->p_session->s_sid; 209 PROC_UNLOCK(p); 210 return (0); 211} 212 213#ifndef _SYS_SYSPROTO_H_ 214struct getuid_args { 215 int dummy; 216}; 217#endif 218/* ARGSUSED */ 219int 220sys_getuid(struct thread *td, struct getuid_args *uap) 221{ 222 223 td->td_retval[0] = td->td_ucred->cr_ruid; 224#if defined(COMPAT_43) 225 td->td_retval[1] = td->td_ucred->cr_uid; 226#endif 227 return (0); 228} 229 230#ifndef _SYS_SYSPROTO_H_ 231struct geteuid_args { 232 int dummy; 233}; 234#endif 235/* ARGSUSED */ 236int 237sys_geteuid(struct thread *td, struct geteuid_args *uap) 238{ 239 240 td->td_retval[0] = td->td_ucred->cr_uid; 241 return (0); 242} 243 244#ifndef _SYS_SYSPROTO_H_ 245struct getgid_args { 246 int dummy; 247}; 248#endif 249/* ARGSUSED */ 250int 251sys_getgid(struct thread *td, struct getgid_args *uap) 252{ 253 254 td->td_retval[0] = td->td_ucred->cr_rgid; 255#if defined(COMPAT_43) 256 td->td_retval[1] = td->td_ucred->cr_groups[0]; 257#endif 258 return (0); 259} 260 261/* 262 * Get effective group ID. The "egid" is groups[0], and could be obtained 263 * via getgroups. This syscall exists because it is somewhat painful to do 264 * correctly in a library function. 265 */ 266#ifndef _SYS_SYSPROTO_H_ 267struct getegid_args { 268 int dummy; 269}; 270#endif 271/* ARGSUSED */ 272int 273sys_getegid(struct thread *td, struct getegid_args *uap) 274{ 275 276 td->td_retval[0] = td->td_ucred->cr_groups[0]; 277 return (0); 278} 279 280#ifndef _SYS_SYSPROTO_H_ 281struct getgroups_args { 282 u_int gidsetsize; 283 gid_t *gidset; 284}; 285#endif 286int 287sys_getgroups(struct thread *td, register struct getgroups_args *uap) 288{ 289 gid_t *groups; 290 u_int ngrp; 291 int error; 292 293 if (uap->gidsetsize < td->td_ucred->cr_ngroups) { 294 if (uap->gidsetsize == 0) 295 ngrp = 0; 296 else 297 return (EINVAL); 298 } else 299 ngrp = td->td_ucred->cr_ngroups; 300 groups = malloc(ngrp * sizeof(*groups), M_TEMP, M_WAITOK); 301 error = kern_getgroups(td, &ngrp, groups); 302 if (error) 303 goto out; 304 if (uap->gidsetsize > 0) 305 error = copyout(groups, uap->gidset, ngrp * sizeof(gid_t)); 306 if (error == 0) 307 td->td_retval[0] = ngrp; 308out: 309 free(groups, M_TEMP); 310 return (error); 311} 312 313int 314kern_getgroups(struct thread *td, u_int *ngrp, gid_t *groups) 315{ 316 struct ucred *cred; 317 318 cred = td->td_ucred; 319 if (*ngrp == 0) { 320 *ngrp = cred->cr_ngroups; 321 return (0); 322 } 323 if (*ngrp < cred->cr_ngroups) 324 return (EINVAL); 325 *ngrp = cred->cr_ngroups; 326 bcopy(cred->cr_groups, groups, *ngrp * sizeof(gid_t)); 327 return (0); 328} 329 330#ifndef _SYS_SYSPROTO_H_ 331struct setsid_args { 332 int dummy; 333}; 334#endif 335/* ARGSUSED */ 336int 337sys_setsid(register struct thread *td, struct setsid_args *uap) 338{ 339 struct pgrp *pgrp; 340 int error; 341 struct proc *p = td->td_proc; 342 struct pgrp *newpgrp; 343 struct session *newsess; 344 345 error = 0; 346 pgrp = NULL; 347 348 newpgrp = malloc(sizeof(struct pgrp), M_PGRP, M_WAITOK | M_ZERO); 349 newsess = malloc(sizeof(struct session), M_SESSION, M_WAITOK | M_ZERO); 350 351 sx_xlock(&proctree_lock); 352 353 if (p->p_pgid == p->p_pid || (pgrp = pgfind(p->p_pid)) != NULL) { 354 if (pgrp != NULL) 355 PGRP_UNLOCK(pgrp); 356 error = EPERM; 357 } else { 358 (void)enterpgrp(p, p->p_pid, newpgrp, newsess); 359 td->td_retval[0] = p->p_pid; 360 newpgrp = NULL; 361 newsess = NULL; 362 } 363 364 sx_xunlock(&proctree_lock); 365 366 if (newpgrp != NULL) 367 free(newpgrp, M_PGRP); 368 if (newsess != NULL) 369 free(newsess, M_SESSION); 370 371 return (error); 372} 373 374/* 375 * set process group (setpgid/old setpgrp) 376 * 377 * caller does setpgid(targpid, targpgid) 378 * 379 * pid must be caller or child of caller (ESRCH) 380 * if a child 381 * pid must be in same session (EPERM) 382 * pid can't have done an exec (EACCES) 383 * if pgid != pid 384 * there must exist some pid in same session having pgid (EPERM) 385 * pid must not be session leader (EPERM) 386 */ 387#ifndef _SYS_SYSPROTO_H_ 388struct setpgid_args { 389 int pid; /* target process id */ 390 int pgid; /* target pgrp id */ 391}; 392#endif 393/* ARGSUSED */ 394int 395sys_setpgid(struct thread *td, register struct setpgid_args *uap) 396{ 397 struct proc *curp = td->td_proc; 398 register struct proc *targp; /* target process */ 399 register struct pgrp *pgrp; /* target pgrp */ 400 int error; 401 struct pgrp *newpgrp; 402 403 if (uap->pgid < 0) 404 return (EINVAL); 405 406 error = 0; 407 408 newpgrp = malloc(sizeof(struct pgrp), M_PGRP, M_WAITOK | M_ZERO); 409 410 sx_xlock(&proctree_lock); 411 if (uap->pid != 0 && uap->pid != curp->p_pid) { 412 if ((targp = pfind(uap->pid)) == NULL) { 413 error = ESRCH; 414 goto done; 415 } 416 if (!inferior(targp)) { 417 PROC_UNLOCK(targp); 418 error = ESRCH; 419 goto done; 420 } 421 if ((error = p_cansee(td, targp))) { 422 PROC_UNLOCK(targp); 423 goto done; 424 } 425 if (targp->p_pgrp == NULL || 426 targp->p_session != curp->p_session) { 427 PROC_UNLOCK(targp); 428 error = EPERM; 429 goto done; 430 } 431 if (targp->p_flag & P_EXEC) { 432 PROC_UNLOCK(targp); 433 error = EACCES; 434 goto done; 435 } 436 PROC_UNLOCK(targp); 437 } else 438 targp = curp; 439 if (SESS_LEADER(targp)) { 440 error = EPERM; 441 goto done; 442 } 443 if (uap->pgid == 0) 444 uap->pgid = targp->p_pid; 445 if ((pgrp = pgfind(uap->pgid)) == NULL) { 446 if (uap->pgid == targp->p_pid) { 447 error = enterpgrp(targp, uap->pgid, newpgrp, 448 NULL); 449 if (error == 0) 450 newpgrp = NULL; 451 } else 452 error = EPERM; 453 } else { 454 if (pgrp == targp->p_pgrp) { 455 PGRP_UNLOCK(pgrp); 456 goto done; 457 } 458 if (pgrp->pg_id != targp->p_pid && 459 pgrp->pg_session != curp->p_session) { 460 PGRP_UNLOCK(pgrp); 461 error = EPERM; 462 goto done; 463 } 464 PGRP_UNLOCK(pgrp); 465 error = enterthispgrp(targp, pgrp); 466 } 467done: 468 sx_xunlock(&proctree_lock); 469 KASSERT((error == 0) || (newpgrp != NULL), 470 ("setpgid failed and newpgrp is NULL")); 471 if (newpgrp != NULL) 472 free(newpgrp, M_PGRP); 473 return (error); 474} 475 476/* 477 * Use the clause in B.4.2.2 that allows setuid/setgid to be 4.2/4.3BSD 478 * compatible. It says that setting the uid/gid to euid/egid is a special 479 * case of "appropriate privilege". Once the rules are expanded out, this 480 * basically means that setuid(nnn) sets all three id's, in all permitted 481 * cases unless _POSIX_SAVED_IDS is enabled. In that case, setuid(getuid()) 482 * does not set the saved id - this is dangerous for traditional BSD 483 * programs. For this reason, we *really* do not want to set 484 * _POSIX_SAVED_IDS and do not want to clear POSIX_APPENDIX_B_4_2_2. 485 */ 486#define POSIX_APPENDIX_B_4_2_2 487 488#ifndef _SYS_SYSPROTO_H_ 489struct setuid_args { 490 uid_t uid; 491}; 492#endif 493/* ARGSUSED */ 494int 495sys_setuid(struct thread *td, struct setuid_args *uap) 496{ 497 struct proc *p = td->td_proc; 498 struct ucred *newcred, *oldcred; 499 uid_t uid; 500 struct uidinfo *uip; 501 int error; 502 503 uid = uap->uid; 504 AUDIT_ARG_UID(uid); 505 newcred = crget(); 506 uip = uifind(uid); 507 PROC_LOCK(p); 508 /* 509 * Copy credentials so other references do not see our changes. 510 */ 511 oldcred = crcopysafe(p, newcred); 512 513#ifdef MAC 514 error = mac_cred_check_setuid(oldcred, uid); 515 if (error) 516 goto fail; 517#endif 518 519 /* 520 * See if we have "permission" by POSIX 1003.1 rules. 521 * 522 * Note that setuid(geteuid()) is a special case of 523 * "appropriate privileges" in appendix B.4.2.2. We need 524 * to use this clause to be compatible with traditional BSD 525 * semantics. Basically, it means that "setuid(xx)" sets all 526 * three id's (assuming you have privs). 527 * 528 * Notes on the logic. We do things in three steps. 529 * 1: We determine if the euid is going to change, and do EPERM 530 * right away. We unconditionally change the euid later if this 531 * test is satisfied, simplifying that part of the logic. 532 * 2: We determine if the real and/or saved uids are going to 533 * change. Determined by compile options. 534 * 3: Change euid last. (after tests in #2 for "appropriate privs") 535 */ 536 if (uid != oldcred->cr_ruid && /* allow setuid(getuid()) */ 537#ifdef _POSIX_SAVED_IDS 538 uid != oldcred->cr_svuid && /* allow setuid(saved gid) */ 539#endif 540#ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */ 541 uid != oldcred->cr_uid && /* allow setuid(geteuid()) */ 542#endif 543 (error = priv_check_cred(oldcred, PRIV_CRED_SETUID, 0)) != 0) 544 goto fail; 545 546#ifdef _POSIX_SAVED_IDS 547 /* 548 * Do we have "appropriate privileges" (are we root or uid == euid) 549 * If so, we are changing the real uid and/or saved uid. 550 */ 551 if ( 552#ifdef POSIX_APPENDIX_B_4_2_2 /* Use the clause from B.4.2.2 */ 553 uid == oldcred->cr_uid || 554#endif 555 /* We are using privs. */ 556 priv_check_cred(oldcred, PRIV_CRED_SETUID, 0) == 0) 557#endif 558 { 559 /* 560 * Set the real uid and transfer proc count to new user. 561 */ 562 if (uid != oldcred->cr_ruid) { 563 change_ruid(newcred, uip); 564 setsugid(p); 565 } 566 /* 567 * Set saved uid 568 * 569 * XXX always set saved uid even if not _POSIX_SAVED_IDS, as 570 * the security of seteuid() depends on it. B.4.2.2 says it 571 * is important that we should do this. 572 */ 573 if (uid != oldcred->cr_svuid) { 574 change_svuid(newcred, uid); 575 setsugid(p); 576 } 577 } 578 579 /* 580 * In all permitted cases, we are changing the euid. 581 */ 582 if (uid != oldcred->cr_uid) { 583 change_euid(newcred, uip); 584 setsugid(p); 585 } 586 p->p_ucred = newcred; 587 PROC_UNLOCK(p); 588#ifdef RACCT 589 racct_proc_ucred_changed(p, oldcred, newcred); 590#endif 591 uifree(uip); 592 crfree(oldcred); 593 return (0); 594 595fail: 596 PROC_UNLOCK(p); 597 uifree(uip); 598 crfree(newcred); 599 return (error); 600} 601 602#ifndef _SYS_SYSPROTO_H_ 603struct seteuid_args { 604 uid_t euid; 605}; 606#endif 607/* ARGSUSED */ 608int 609sys_seteuid(struct thread *td, struct seteuid_args *uap) 610{ 611 struct proc *p = td->td_proc; 612 struct ucred *newcred, *oldcred; 613 uid_t euid; 614 struct uidinfo *euip; 615 int error; 616 617 euid = uap->euid; 618 AUDIT_ARG_EUID(euid); 619 newcred = crget(); 620 euip = uifind(euid); 621 PROC_LOCK(p); 622 /* 623 * Copy credentials so other references do not see our changes. 624 */ 625 oldcred = crcopysafe(p, newcred); 626 627#ifdef MAC 628 error = mac_cred_check_seteuid(oldcred, euid); 629 if (error) 630 goto fail; 631#endif 632 633 if (euid != oldcred->cr_ruid && /* allow seteuid(getuid()) */ 634 euid != oldcred->cr_svuid && /* allow seteuid(saved uid) */ 635 (error = priv_check_cred(oldcred, PRIV_CRED_SETEUID, 0)) != 0) 636 goto fail; 637 638 /* 639 * Everything's okay, do it. 640 */ 641 if (oldcred->cr_uid != euid) { 642 change_euid(newcred, euip); 643 setsugid(p); 644 } 645 p->p_ucred = newcred; 646 PROC_UNLOCK(p); 647 uifree(euip); 648 crfree(oldcred); 649 return (0); 650 651fail: 652 PROC_UNLOCK(p); 653 uifree(euip); 654 crfree(newcred); 655 return (error); 656} 657 658#ifndef _SYS_SYSPROTO_H_ 659struct setgid_args { 660 gid_t gid; 661}; 662#endif 663/* ARGSUSED */ 664int 665sys_setgid(struct thread *td, struct setgid_args *uap) 666{ 667 struct proc *p = td->td_proc; 668 struct ucred *newcred, *oldcred; 669 gid_t gid; 670 int error; 671 672 gid = uap->gid; 673 AUDIT_ARG_GID(gid); 674 newcred = crget(); 675 PROC_LOCK(p); 676 oldcred = crcopysafe(p, newcred); 677 678#ifdef MAC 679 error = mac_cred_check_setgid(oldcred, gid); 680 if (error) 681 goto fail; 682#endif 683 684 /* 685 * See if we have "permission" by POSIX 1003.1 rules. 686 * 687 * Note that setgid(getegid()) is a special case of 688 * "appropriate privileges" in appendix B.4.2.2. We need 689 * to use this clause to be compatible with traditional BSD 690 * semantics. Basically, it means that "setgid(xx)" sets all 691 * three id's (assuming you have privs). 692 * 693 * For notes on the logic here, see setuid() above. 694 */ 695 if (gid != oldcred->cr_rgid && /* allow setgid(getgid()) */ 696#ifdef _POSIX_SAVED_IDS 697 gid != oldcred->cr_svgid && /* allow setgid(saved gid) */ 698#endif 699#ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */ 700 gid != oldcred->cr_groups[0] && /* allow setgid(getegid()) */ 701#endif 702 (error = priv_check_cred(oldcred, PRIV_CRED_SETGID, 0)) != 0) 703 goto fail; 704 705#ifdef _POSIX_SAVED_IDS 706 /* 707 * Do we have "appropriate privileges" (are we root or gid == egid) 708 * If so, we are changing the real uid and saved gid. 709 */ 710 if ( 711#ifdef POSIX_APPENDIX_B_4_2_2 /* use the clause from B.4.2.2 */ 712 gid == oldcred->cr_groups[0] || 713#endif 714 /* We are using privs. */ 715 priv_check_cred(oldcred, PRIV_CRED_SETGID, 0) == 0) 716#endif 717 { 718 /* 719 * Set real gid 720 */ 721 if (oldcred->cr_rgid != gid) { 722 change_rgid(newcred, gid); 723 setsugid(p); 724 } 725 /* 726 * Set saved gid 727 * 728 * XXX always set saved gid even if not _POSIX_SAVED_IDS, as 729 * the security of setegid() depends on it. B.4.2.2 says it 730 * is important that we should do this. 731 */ 732 if (oldcred->cr_svgid != gid) { 733 change_svgid(newcred, gid); 734 setsugid(p); 735 } 736 } 737 /* 738 * In all cases permitted cases, we are changing the egid. 739 * Copy credentials so other references do not see our changes. 740 */ 741 if (oldcred->cr_groups[0] != gid) { 742 change_egid(newcred, gid); 743 setsugid(p); 744 } 745 p->p_ucred = newcred; 746 PROC_UNLOCK(p); 747 crfree(oldcred); 748 return (0); 749 750fail: 751 PROC_UNLOCK(p); 752 crfree(newcred); 753 return (error); 754} 755 756#ifndef _SYS_SYSPROTO_H_ 757struct setegid_args { 758 gid_t egid; 759}; 760#endif 761/* ARGSUSED */ 762int 763sys_setegid(struct thread *td, struct setegid_args *uap) 764{ 765 struct proc *p = td->td_proc; 766 struct ucred *newcred, *oldcred; 767 gid_t egid; 768 int error; 769 770 egid = uap->egid; 771 AUDIT_ARG_EGID(egid); 772 newcred = crget(); 773 PROC_LOCK(p); 774 oldcred = crcopysafe(p, newcred); 775 776#ifdef MAC 777 error = mac_cred_check_setegid(oldcred, egid); 778 if (error) 779 goto fail; 780#endif 781 782 if (egid != oldcred->cr_rgid && /* allow setegid(getgid()) */ 783 egid != oldcred->cr_svgid && /* allow setegid(saved gid) */ 784 (error = priv_check_cred(oldcred, PRIV_CRED_SETEGID, 0)) != 0) 785 goto fail; 786 787 if (oldcred->cr_groups[0] != egid) { 788 change_egid(newcred, egid); 789 setsugid(p); 790 } 791 p->p_ucred = newcred; 792 PROC_UNLOCK(p); 793 crfree(oldcred); 794 return (0); 795 796fail: 797 PROC_UNLOCK(p); 798 crfree(newcred); 799 return (error); 800} 801 802#ifndef _SYS_SYSPROTO_H_ 803struct setgroups_args { 804 u_int gidsetsize; 805 gid_t *gidset; 806}; 807#endif 808/* ARGSUSED */ 809int 810sys_setgroups(struct thread *td, struct setgroups_args *uap) 811{ 812 gid_t *groups = NULL; 813 int error; 814 815 if (uap->gidsetsize > ngroups_max + 1) 816 return (EINVAL); 817 groups = malloc(uap->gidsetsize * sizeof(gid_t), M_TEMP, M_WAITOK); 818 error = copyin(uap->gidset, groups, uap->gidsetsize * sizeof(gid_t)); 819 if (error) 820 goto out; 821 error = kern_setgroups(td, uap->gidsetsize, groups); 822out: 823 free(groups, M_TEMP); 824 return (error); 825} 826 827int 828kern_setgroups(struct thread *td, u_int ngrp, gid_t *groups) 829{ 830 struct proc *p = td->td_proc; 831 struct ucred *newcred, *oldcred; 832 int error; 833 834 if (ngrp > ngroups_max + 1) 835 return (EINVAL); 836 AUDIT_ARG_GROUPSET(groups, ngrp); 837 newcred = crget(); 838 crextend(newcred, ngrp); 839 PROC_LOCK(p); 840 oldcred = crcopysafe(p, newcred); 841 842#ifdef MAC 843 error = mac_cred_check_setgroups(oldcred, ngrp, groups); 844 if (error) 845 goto fail; 846#endif 847 848 error = priv_check_cred(oldcred, PRIV_CRED_SETGROUPS, 0); 849 if (error) 850 goto fail; 851 852 if (ngrp < 1) { 853 /* 854 * setgroups(0, NULL) is a legitimate way of clearing the 855 * groups vector on non-BSD systems (which generally do not 856 * have the egid in the groups[0]). We risk security holes 857 * when running non-BSD software if we do not do the same. 858 */ 859 newcred->cr_ngroups = 1; 860 } else { 861 crsetgroups_locked(newcred, ngrp, groups); 862 } 863 setsugid(p); 864 p->p_ucred = newcred; 865 PROC_UNLOCK(p); 866 crfree(oldcred); 867 return (0); 868 869fail: 870 PROC_UNLOCK(p); 871 crfree(newcred); 872 return (error); 873} 874 875#ifndef _SYS_SYSPROTO_H_ 876struct setreuid_args { 877 uid_t ruid; 878 uid_t euid; 879}; 880#endif 881/* ARGSUSED */ 882int 883sys_setreuid(register struct thread *td, struct setreuid_args *uap) 884{ 885 struct proc *p = td->td_proc; 886 struct ucred *newcred, *oldcred; 887 uid_t euid, ruid; 888 struct uidinfo *euip, *ruip; 889 int error; 890 891 euid = uap->euid; 892 ruid = uap->ruid; 893 AUDIT_ARG_EUID(euid); 894 AUDIT_ARG_RUID(ruid); 895 newcred = crget(); 896 euip = uifind(euid); 897 ruip = uifind(ruid); 898 PROC_LOCK(p); 899 oldcred = crcopysafe(p, newcred); 900 901#ifdef MAC 902 error = mac_cred_check_setreuid(oldcred, ruid, euid); 903 if (error) 904 goto fail; 905#endif 906 907 if (((ruid != (uid_t)-1 && ruid != oldcred->cr_ruid && 908 ruid != oldcred->cr_svuid) || 909 (euid != (uid_t)-1 && euid != oldcred->cr_uid && 910 euid != oldcred->cr_ruid && euid != oldcred->cr_svuid)) && 911 (error = priv_check_cred(oldcred, PRIV_CRED_SETREUID, 0)) != 0) 912 goto fail; 913 914 if (euid != (uid_t)-1 && oldcred->cr_uid != euid) { 915 change_euid(newcred, euip); 916 setsugid(p); 917 } 918 if (ruid != (uid_t)-1 && oldcred->cr_ruid != ruid) { 919 change_ruid(newcred, ruip); 920 setsugid(p); 921 } 922 if ((ruid != (uid_t)-1 || newcred->cr_uid != newcred->cr_ruid) && 923 newcred->cr_svuid != newcred->cr_uid) { 924 change_svuid(newcred, newcred->cr_uid); 925 setsugid(p); 926 } 927 p->p_ucred = newcred; 928 PROC_UNLOCK(p); 929#ifdef RACCT 930 racct_proc_ucred_changed(p, oldcred, newcred); 931#endif 932 uifree(ruip); 933 uifree(euip); 934 crfree(oldcred); 935 return (0); 936 937fail: 938 PROC_UNLOCK(p); 939 uifree(ruip); 940 uifree(euip); 941 crfree(newcred); 942 return (error); 943} 944 945#ifndef _SYS_SYSPROTO_H_ 946struct setregid_args { 947 gid_t rgid; 948 gid_t egid; 949}; 950#endif 951/* ARGSUSED */ 952int 953sys_setregid(register struct thread *td, struct setregid_args *uap) 954{ 955 struct proc *p = td->td_proc; 956 struct ucred *newcred, *oldcred; 957 gid_t egid, rgid; 958 int error; 959 960 egid = uap->egid; 961 rgid = uap->rgid; 962 AUDIT_ARG_EGID(egid); 963 AUDIT_ARG_RGID(rgid); 964 newcred = crget(); 965 PROC_LOCK(p); 966 oldcred = crcopysafe(p, newcred); 967 968#ifdef MAC 969 error = mac_cred_check_setregid(oldcred, rgid, egid); 970 if (error) 971 goto fail; 972#endif 973 974 if (((rgid != (gid_t)-1 && rgid != oldcred->cr_rgid && 975 rgid != oldcred->cr_svgid) || 976 (egid != (gid_t)-1 && egid != oldcred->cr_groups[0] && 977 egid != oldcred->cr_rgid && egid != oldcred->cr_svgid)) && 978 (error = priv_check_cred(oldcred, PRIV_CRED_SETREGID, 0)) != 0) 979 goto fail; 980 981 if (egid != (gid_t)-1 && oldcred->cr_groups[0] != egid) { 982 change_egid(newcred, egid); 983 setsugid(p); 984 } 985 if (rgid != (gid_t)-1 && oldcred->cr_rgid != rgid) { 986 change_rgid(newcred, rgid); 987 setsugid(p); 988 } 989 if ((rgid != (gid_t)-1 || newcred->cr_groups[0] != newcred->cr_rgid) && 990 newcred->cr_svgid != newcred->cr_groups[0]) { 991 change_svgid(newcred, newcred->cr_groups[0]); 992 setsugid(p); 993 } 994 p->p_ucred = newcred; 995 PROC_UNLOCK(p); 996 crfree(oldcred); 997 return (0); 998 999fail: 1000 PROC_UNLOCK(p); 1001 crfree(newcred); 1002 return (error); 1003} 1004 1005/* 1006 * setresuid(ruid, euid, suid) is like setreuid except control over the saved 1007 * uid is explicit. 1008 */ 1009#ifndef _SYS_SYSPROTO_H_ 1010struct setresuid_args { 1011 uid_t ruid; 1012 uid_t euid; 1013 uid_t suid; 1014}; 1015#endif 1016/* ARGSUSED */ 1017int 1018sys_setresuid(register struct thread *td, struct setresuid_args *uap) 1019{ 1020 struct proc *p = td->td_proc; 1021 struct ucred *newcred, *oldcred; 1022 uid_t euid, ruid, suid; 1023 struct uidinfo *euip, *ruip; 1024 int error; 1025 1026 euid = uap->euid; 1027 ruid = uap->ruid; 1028 suid = uap->suid; 1029 AUDIT_ARG_EUID(euid); 1030 AUDIT_ARG_RUID(ruid); 1031 AUDIT_ARG_SUID(suid); 1032 newcred = crget(); 1033 euip = uifind(euid); 1034 ruip = uifind(ruid); 1035 PROC_LOCK(p); 1036 oldcred = crcopysafe(p, newcred); 1037 1038#ifdef MAC 1039 error = mac_cred_check_setresuid(oldcred, ruid, euid, suid); 1040 if (error) 1041 goto fail; 1042#endif 1043 1044 if (((ruid != (uid_t)-1 && ruid != oldcred->cr_ruid && 1045 ruid != oldcred->cr_svuid && 1046 ruid != oldcred->cr_uid) || 1047 (euid != (uid_t)-1 && euid != oldcred->cr_ruid && 1048 euid != oldcred->cr_svuid && 1049 euid != oldcred->cr_uid) || 1050 (suid != (uid_t)-1 && suid != oldcred->cr_ruid && 1051 suid != oldcred->cr_svuid && 1052 suid != oldcred->cr_uid)) && 1053 (error = priv_check_cred(oldcred, PRIV_CRED_SETRESUID, 0)) != 0) 1054 goto fail; 1055 1056 if (euid != (uid_t)-1 && oldcred->cr_uid != euid) { 1057 change_euid(newcred, euip); 1058 setsugid(p); 1059 } 1060 if (ruid != (uid_t)-1 && oldcred->cr_ruid != ruid) { 1061 change_ruid(newcred, ruip); 1062 setsugid(p); 1063 } 1064 if (suid != (uid_t)-1 && oldcred->cr_svuid != suid) { 1065 change_svuid(newcred, suid); 1066 setsugid(p); 1067 } 1068 p->p_ucred = newcred; 1069 PROC_UNLOCK(p); 1070#ifdef RACCT 1071 racct_proc_ucred_changed(p, oldcred, newcred); 1072#endif 1073 uifree(ruip); 1074 uifree(euip); 1075 crfree(oldcred); 1076 return (0); 1077 1078fail: 1079 PROC_UNLOCK(p); 1080 uifree(ruip); 1081 uifree(euip); 1082 crfree(newcred); 1083 return (error); 1084 1085} 1086 1087/* 1088 * setresgid(rgid, egid, sgid) is like setregid except control over the saved 1089 * gid is explicit. 1090 */ 1091#ifndef _SYS_SYSPROTO_H_ 1092struct setresgid_args { 1093 gid_t rgid; 1094 gid_t egid; 1095 gid_t sgid; 1096}; 1097#endif 1098/* ARGSUSED */ 1099int 1100sys_setresgid(register struct thread *td, struct setresgid_args *uap) 1101{ 1102 struct proc *p = td->td_proc; 1103 struct ucred *newcred, *oldcred; 1104 gid_t egid, rgid, sgid; 1105 int error; 1106 1107 egid = uap->egid; 1108 rgid = uap->rgid; 1109 sgid = uap->sgid; 1110 AUDIT_ARG_EGID(egid); 1111 AUDIT_ARG_RGID(rgid); 1112 AUDIT_ARG_SGID(sgid); 1113 newcred = crget(); 1114 PROC_LOCK(p); 1115 oldcred = crcopysafe(p, newcred); 1116 1117#ifdef MAC 1118 error = mac_cred_check_setresgid(oldcred, rgid, egid, sgid); 1119 if (error) 1120 goto fail; 1121#endif 1122 1123 if (((rgid != (gid_t)-1 && rgid != oldcred->cr_rgid && 1124 rgid != oldcred->cr_svgid && 1125 rgid != oldcred->cr_groups[0]) || 1126 (egid != (gid_t)-1 && egid != oldcred->cr_rgid && 1127 egid != oldcred->cr_svgid && 1128 egid != oldcred->cr_groups[0]) || 1129 (sgid != (gid_t)-1 && sgid != oldcred->cr_rgid && 1130 sgid != oldcred->cr_svgid && 1131 sgid != oldcred->cr_groups[0])) && 1132 (error = priv_check_cred(oldcred, PRIV_CRED_SETRESGID, 0)) != 0) 1133 goto fail; 1134 1135 if (egid != (gid_t)-1 && oldcred->cr_groups[0] != egid) { 1136 change_egid(newcred, egid); 1137 setsugid(p); 1138 } 1139 if (rgid != (gid_t)-1 && oldcred->cr_rgid != rgid) { 1140 change_rgid(newcred, rgid); 1141 setsugid(p); 1142 } 1143 if (sgid != (gid_t)-1 && oldcred->cr_svgid != sgid) { 1144 change_svgid(newcred, sgid); 1145 setsugid(p); 1146 } 1147 p->p_ucred = newcred; 1148 PROC_UNLOCK(p); 1149 crfree(oldcred); 1150 return (0); 1151 1152fail: 1153 PROC_UNLOCK(p); 1154 crfree(newcred); 1155 return (error); 1156} 1157 1158#ifndef _SYS_SYSPROTO_H_ 1159struct getresuid_args { 1160 uid_t *ruid; 1161 uid_t *euid; 1162 uid_t *suid; 1163}; 1164#endif 1165/* ARGSUSED */ 1166int 1167sys_getresuid(register struct thread *td, struct getresuid_args *uap) 1168{ 1169 struct ucred *cred; 1170 int error1 = 0, error2 = 0, error3 = 0; 1171 1172 cred = td->td_ucred; 1173 if (uap->ruid) 1174 error1 = copyout(&cred->cr_ruid, 1175 uap->ruid, sizeof(cred->cr_ruid)); 1176 if (uap->euid) 1177 error2 = copyout(&cred->cr_uid, 1178 uap->euid, sizeof(cred->cr_uid)); 1179 if (uap->suid) 1180 error3 = copyout(&cred->cr_svuid, 1181 uap->suid, sizeof(cred->cr_svuid)); 1182 return (error1 ? error1 : error2 ? error2 : error3); 1183} 1184 1185#ifndef _SYS_SYSPROTO_H_ 1186struct getresgid_args { 1187 gid_t *rgid; 1188 gid_t *egid; 1189 gid_t *sgid; 1190}; 1191#endif 1192/* ARGSUSED */ 1193int 1194sys_getresgid(register struct thread *td, struct getresgid_args *uap) 1195{ 1196 struct ucred *cred; 1197 int error1 = 0, error2 = 0, error3 = 0; 1198 1199 cred = td->td_ucred; 1200 if (uap->rgid) 1201 error1 = copyout(&cred->cr_rgid, 1202 uap->rgid, sizeof(cred->cr_rgid)); 1203 if (uap->egid) 1204 error2 = copyout(&cred->cr_groups[0], 1205 uap->egid, sizeof(cred->cr_groups[0])); 1206 if (uap->sgid) 1207 error3 = copyout(&cred->cr_svgid, 1208 uap->sgid, sizeof(cred->cr_svgid)); 1209 return (error1 ? error1 : error2 ? error2 : error3); 1210} 1211 1212#ifndef _SYS_SYSPROTO_H_ 1213struct issetugid_args { 1214 int dummy; 1215}; 1216#endif 1217/* ARGSUSED */ 1218int 1219sys_issetugid(register struct thread *td, struct issetugid_args *uap) 1220{ 1221 struct proc *p = td->td_proc; 1222 1223 /* 1224 * Note: OpenBSD sets a P_SUGIDEXEC flag set at execve() time, 1225 * we use P_SUGID because we consider changing the owners as 1226 * "tainting" as well. 1227 * This is significant for procs that start as root and "become" 1228 * a user without an exec - programs cannot know *everything* 1229 * that libc *might* have put in their data segment. 1230 */ 1231 PROC_LOCK(p); 1232 td->td_retval[0] = (p->p_flag & P_SUGID) ? 1 : 0; 1233 PROC_UNLOCK(p); 1234 return (0); 1235} 1236 1237int 1238sys___setugid(struct thread *td, struct __setugid_args *uap) 1239{ 1240#ifdef REGRESSION 1241 struct proc *p; 1242 1243 p = td->td_proc; 1244 switch (uap->flag) { 1245 case 0: 1246 PROC_LOCK(p); 1247 p->p_flag &= ~P_SUGID; 1248 PROC_UNLOCK(p); 1249 return (0); 1250 case 1: 1251 PROC_LOCK(p); 1252 p->p_flag |= P_SUGID; 1253 PROC_UNLOCK(p); 1254 return (0); 1255 default: 1256 return (EINVAL); 1257 } 1258#else /* !REGRESSION */ 1259 1260 return (ENOSYS); 1261#endif /* REGRESSION */ 1262} 1263 1264/* 1265 * Check if gid is a member of the group set. 1266 */ 1267int 1268groupmember(gid_t gid, struct ucred *cred) 1269{ 1270 int l; 1271 int h; 1272 int m; 1273 1274 if (cred->cr_groups[0] == gid) 1275 return(1); 1276 1277 /* 1278 * If gid was not our primary group, perform a binary search 1279 * of the supplemental groups. This is possible because we 1280 * sort the groups in crsetgroups(). 1281 */ 1282 l = 1; 1283 h = cred->cr_ngroups; 1284 while (l < h) { 1285 m = l + ((h - l) / 2); 1286 if (cred->cr_groups[m] < gid) 1287 l = m + 1; 1288 else 1289 h = m; 1290 } 1291 if ((l < cred->cr_ngroups) && (cred->cr_groups[l] == gid)) 1292 return (1); 1293 1294 return (0); 1295} 1296 1297/* 1298 * Test the active securelevel against a given level. securelevel_gt() 1299 * implements (securelevel > level). securelevel_ge() implements 1300 * (securelevel >= level). Note that the logic is inverted -- these 1301 * functions return EPERM on "success" and 0 on "failure". 1302 * 1303 * Due to care taken when setting the securelevel, we know that no jail will 1304 * be less secure that its parent (or the physical system), so it is sufficient 1305 * to test the current jail only. 1306 * 1307 * XXXRW: Possibly since this has to do with privilege, it should move to 1308 * kern_priv.c. 1309 */ 1310int 1311securelevel_gt(struct ucred *cr, int level) 1312{ 1313 1314 return (cr->cr_prison->pr_securelevel > level ? EPERM : 0); 1315} 1316 1317int 1318securelevel_ge(struct ucred *cr, int level) 1319{ 1320 1321 return (cr->cr_prison->pr_securelevel >= level ? EPERM : 0); 1322} 1323 1324/* 1325 * 'see_other_uids' determines whether or not visibility of processes 1326 * and sockets with credentials holding different real uids is possible 1327 * using a variety of system MIBs. 1328 * XXX: data declarations should be together near the beginning of the file. 1329 */ 1330static int see_other_uids = 1; 1331SYSCTL_INT(_security_bsd, OID_AUTO, see_other_uids, CTLFLAG_RW, 1332 &see_other_uids, 0, 1333 "Unprivileged processes may see subjects/objects with different real uid"); 1334 1335/*- 1336 * Determine if u1 "can see" the subject specified by u2, according to the 1337 * 'see_other_uids' policy. 1338 * Returns: 0 for permitted, ESRCH otherwise 1339 * Locks: none 1340 * References: *u1 and *u2 must not change during the call 1341 * u1 may equal u2, in which case only one reference is required 1342 */ 1343static int 1344cr_seeotheruids(struct ucred *u1, struct ucred *u2) 1345{ 1346 1347 if (!see_other_uids && u1->cr_ruid != u2->cr_ruid) { 1348 if (priv_check_cred(u1, PRIV_SEEOTHERUIDS, 0) != 0) 1349 return (ESRCH); 1350 } 1351 return (0); 1352} 1353 1354/* 1355 * 'see_other_gids' determines whether or not visibility of processes 1356 * and sockets with credentials holding different real gids is possible 1357 * using a variety of system MIBs. 1358 * XXX: data declarations should be together near the beginning of the file. 1359 */ 1360static int see_other_gids = 1; 1361SYSCTL_INT(_security_bsd, OID_AUTO, see_other_gids, CTLFLAG_RW, 1362 &see_other_gids, 0, 1363 "Unprivileged processes may see subjects/objects with different real gid"); 1364 1365/* 1366 * Determine if u1 can "see" the subject specified by u2, according to the 1367 * 'see_other_gids' policy. 1368 * Returns: 0 for permitted, ESRCH otherwise 1369 * Locks: none 1370 * References: *u1 and *u2 must not change during the call 1371 * u1 may equal u2, in which case only one reference is required 1372 */ 1373static int 1374cr_seeothergids(struct ucred *u1, struct ucred *u2) 1375{ 1376 int i, match; 1377 1378 if (!see_other_gids) { 1379 match = 0; 1380 for (i = 0; i < u1->cr_ngroups; i++) { 1381 if (groupmember(u1->cr_groups[i], u2)) 1382 match = 1; 1383 if (match) 1384 break; 1385 } 1386 if (!match) { 1387 if (priv_check_cred(u1, PRIV_SEEOTHERGIDS, 0) != 0) 1388 return (ESRCH); 1389 } 1390 } 1391 return (0); 1392} 1393 1394/*- 1395 * Determine if u1 "can see" the subject specified by u2. 1396 * Returns: 0 for permitted, an errno value otherwise 1397 * Locks: none 1398 * References: *u1 and *u2 must not change during the call 1399 * u1 may equal u2, in which case only one reference is required 1400 */ 1401int 1402cr_cansee(struct ucred *u1, struct ucred *u2) 1403{ 1404 int error; 1405 1406 if ((error = prison_check(u1, u2))) 1407 return (error); 1408#ifdef MAC 1409 if ((error = mac_cred_check_visible(u1, u2))) 1410 return (error); 1411#endif 1412 if ((error = cr_seeotheruids(u1, u2))) 1413 return (error); 1414 if ((error = cr_seeothergids(u1, u2))) 1415 return (error); 1416 return (0); 1417} 1418 1419/*- 1420 * Determine if td "can see" the subject specified by p. 1421 * Returns: 0 for permitted, an errno value otherwise 1422 * Locks: Sufficient locks to protect p->p_ucred must be held. td really 1423 * should be curthread. 1424 * References: td and p must be valid for the lifetime of the call 1425 */ 1426int 1427p_cansee(struct thread *td, struct proc *p) 1428{ 1429 1430 /* Wrap cr_cansee() for all functionality. */ 1431 KASSERT(td == curthread, ("%s: td not curthread", __func__)); 1432 PROC_LOCK_ASSERT(p, MA_OWNED); 1433 return (cr_cansee(td->td_ucred, p->p_ucred)); 1434} 1435 1436/* 1437 * 'conservative_signals' prevents the delivery of a broad class of 1438 * signals by unprivileged processes to processes that have changed their 1439 * credentials since the last invocation of execve(). This can prevent 1440 * the leakage of cached information or retained privileges as a result 1441 * of a common class of signal-related vulnerabilities. However, this 1442 * may interfere with some applications that expect to be able to 1443 * deliver these signals to peer processes after having given up 1444 * privilege. 1445 */ 1446static int conservative_signals = 1; 1447SYSCTL_INT(_security_bsd, OID_AUTO, conservative_signals, CTLFLAG_RW, 1448 &conservative_signals, 0, "Unprivileged processes prevented from " 1449 "sending certain signals to processes whose credentials have changed"); 1450/*- 1451 * Determine whether cred may deliver the specified signal to proc. 1452 * Returns: 0 for permitted, an errno value otherwise. 1453 * Locks: A lock must be held for proc. 1454 * References: cred and proc must be valid for the lifetime of the call. 1455 */ 1456int 1457cr_cansignal(struct ucred *cred, struct proc *proc, int signum) 1458{ 1459 int error; 1460 1461 PROC_LOCK_ASSERT(proc, MA_OWNED); 1462 /* 1463 * Jail semantics limit the scope of signalling to proc in the 1464 * same jail as cred, if cred is in jail. 1465 */ 1466 error = prison_check(cred, proc->p_ucred); 1467 if (error) 1468 return (error); 1469#ifdef MAC 1470 if ((error = mac_proc_check_signal(cred, proc, signum))) 1471 return (error); 1472#endif 1473 if ((error = cr_seeotheruids(cred, proc->p_ucred))) 1474 return (error); 1475 if ((error = cr_seeothergids(cred, proc->p_ucred))) 1476 return (error); 1477 1478 /* 1479 * UNIX signal semantics depend on the status of the P_SUGID 1480 * bit on the target process. If the bit is set, then additional 1481 * restrictions are placed on the set of available signals. 1482 */ 1483 if (conservative_signals && (proc->p_flag & P_SUGID)) { 1484 switch (signum) { 1485 case 0: 1486 case SIGKILL: 1487 case SIGINT: 1488 case SIGTERM: 1489 case SIGALRM: 1490 case SIGSTOP: 1491 case SIGTTIN: 1492 case SIGTTOU: 1493 case SIGTSTP: 1494 case SIGHUP: 1495 case SIGUSR1: 1496 case SIGUSR2: 1497 /* 1498 * Generally, permit job and terminal control 1499 * signals. 1500 */ 1501 break; 1502 default: 1503 /* Not permitted without privilege. */ 1504 error = priv_check_cred(cred, PRIV_SIGNAL_SUGID, 0); 1505 if (error) 1506 return (error); 1507 } 1508 } 1509 1510 /* 1511 * Generally, the target credential's ruid or svuid must match the 1512 * subject credential's ruid or euid. 1513 */ 1514 if (cred->cr_ruid != proc->p_ucred->cr_ruid && 1515 cred->cr_ruid != proc->p_ucred->cr_svuid && 1516 cred->cr_uid != proc->p_ucred->cr_ruid && 1517 cred->cr_uid != proc->p_ucred->cr_svuid) { 1518 error = priv_check_cred(cred, PRIV_SIGNAL_DIFFCRED, 0); 1519 if (error) 1520 return (error); 1521 } 1522 1523 return (0); 1524} 1525 1526/*- 1527 * Determine whether td may deliver the specified signal to p. 1528 * Returns: 0 for permitted, an errno value otherwise 1529 * Locks: Sufficient locks to protect various components of td and p 1530 * must be held. td must be curthread, and a lock must be 1531 * held for p. 1532 * References: td and p must be valid for the lifetime of the call 1533 */ 1534int 1535p_cansignal(struct thread *td, struct proc *p, int signum) 1536{ 1537 1538 KASSERT(td == curthread, ("%s: td not curthread", __func__)); 1539 PROC_LOCK_ASSERT(p, MA_OWNED); 1540 if (td->td_proc == p) 1541 return (0); 1542 1543 /* 1544 * UNIX signalling semantics require that processes in the same 1545 * session always be able to deliver SIGCONT to one another, 1546 * overriding the remaining protections. 1547 */ 1548 /* XXX: This will require an additional lock of some sort. */ 1549 if (signum == SIGCONT && td->td_proc->p_session == p->p_session) 1550 return (0); 1551 /* 1552 * Some compat layers use SIGTHR and higher signals for 1553 * communication between different kernel threads of the same 1554 * process, so that they expect that it's always possible to 1555 * deliver them, even for suid applications where cr_cansignal() can 1556 * deny such ability for security consideration. It should be 1557 * pretty safe to do since the only way to create two processes 1558 * with the same p_leader is via rfork(2). 1559 */ 1560 if (td->td_proc->p_leader != NULL && signum >= SIGTHR && 1561 signum < SIGTHR + 4 && td->td_proc->p_leader == p->p_leader) 1562 return (0); 1563 1564 return (cr_cansignal(td->td_ucred, p, signum)); 1565} 1566 1567/*- 1568 * Determine whether td may reschedule p. 1569 * Returns: 0 for permitted, an errno value otherwise 1570 * Locks: Sufficient locks to protect various components of td and p 1571 * must be held. td must be curthread, and a lock must 1572 * be held for p. 1573 * References: td and p must be valid for the lifetime of the call 1574 */ 1575int 1576p_cansched(struct thread *td, struct proc *p) 1577{ 1578 int error; 1579 1580 KASSERT(td == curthread, ("%s: td not curthread", __func__)); 1581 PROC_LOCK_ASSERT(p, MA_OWNED); 1582 if (td->td_proc == p) 1583 return (0); 1584 if ((error = prison_check(td->td_ucred, p->p_ucred))) 1585 return (error); 1586#ifdef MAC 1587 if ((error = mac_proc_check_sched(td->td_ucred, p))) 1588 return (error); 1589#endif 1590 if ((error = cr_seeotheruids(td->td_ucred, p->p_ucred))) 1591 return (error); 1592 if ((error = cr_seeothergids(td->td_ucred, p->p_ucred))) 1593 return (error); 1594 if (td->td_ucred->cr_ruid != p->p_ucred->cr_ruid && 1595 td->td_ucred->cr_uid != p->p_ucred->cr_ruid) { 1596 error = priv_check(td, PRIV_SCHED_DIFFCRED); 1597 if (error) 1598 return (error); 1599 } 1600 return (0); 1601} 1602 1603/* 1604 * The 'unprivileged_proc_debug' flag may be used to disable a variety of 1605 * unprivileged inter-process debugging services, including some procfs 1606 * functionality, ptrace(), and ktrace(). In the past, inter-process 1607 * debugging has been involved in a variety of security problems, and sites 1608 * not requiring the service might choose to disable it when hardening 1609 * systems. 1610 * 1611 * XXX: Should modifying and reading this variable require locking? 1612 * XXX: data declarations should be together near the beginning of the file. 1613 */ 1614static int unprivileged_proc_debug = 1; 1615SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_proc_debug, CTLFLAG_RW, 1616 &unprivileged_proc_debug, 0, 1617 "Unprivileged processes may use process debugging facilities"); 1618 1619/*- 1620 * Determine whether td may debug p. 1621 * Returns: 0 for permitted, an errno value otherwise 1622 * Locks: Sufficient locks to protect various components of td and p 1623 * must be held. td must be curthread, and a lock must 1624 * be held for p. 1625 * References: td and p must be valid for the lifetime of the call 1626 */ 1627int 1628p_candebug(struct thread *td, struct proc *p) 1629{ 1630 int credentialchanged, error, grpsubset, i, uidsubset; 1631 1632 KASSERT(td == curthread, ("%s: td not curthread", __func__)); 1633 PROC_LOCK_ASSERT(p, MA_OWNED); 1634 if (!unprivileged_proc_debug) { 1635 error = priv_check(td, PRIV_DEBUG_UNPRIV); 1636 if (error) 1637 return (error); 1638 } 1639 if (td->td_proc == p) 1640 return (0); 1641 if ((error = prison_check(td->td_ucred, p->p_ucred))) 1642 return (error); 1643#ifdef MAC 1644 if ((error = mac_proc_check_debug(td->td_ucred, p))) 1645 return (error); 1646#endif 1647 if ((error = cr_seeotheruids(td->td_ucred, p->p_ucred))) 1648 return (error); 1649 if ((error = cr_seeothergids(td->td_ucred, p->p_ucred))) 1650 return (error); 1651 1652 /* 1653 * Is p's group set a subset of td's effective group set? This 1654 * includes p's egid, group access list, rgid, and svgid. 1655 */ 1656 grpsubset = 1; 1657 for (i = 0; i < p->p_ucred->cr_ngroups; i++) { 1658 if (!groupmember(p->p_ucred->cr_groups[i], td->td_ucred)) { 1659 grpsubset = 0; 1660 break; 1661 } 1662 } 1663 grpsubset = grpsubset && 1664 groupmember(p->p_ucred->cr_rgid, td->td_ucred) && 1665 groupmember(p->p_ucred->cr_svgid, td->td_ucred); 1666 1667 /* 1668 * Are the uids present in p's credential equal to td's 1669 * effective uid? This includes p's euid, svuid, and ruid. 1670 */ 1671 uidsubset = (td->td_ucred->cr_uid == p->p_ucred->cr_uid && 1672 td->td_ucred->cr_uid == p->p_ucred->cr_svuid && 1673 td->td_ucred->cr_uid == p->p_ucred->cr_ruid); 1674 1675 /* 1676 * Has the credential of the process changed since the last exec()? 1677 */ 1678 credentialchanged = (p->p_flag & P_SUGID); 1679 1680 /* 1681 * If p's gids aren't a subset, or the uids aren't a subset, 1682 * or the credential has changed, require appropriate privilege 1683 * for td to debug p. 1684 */ 1685 if (!grpsubset || !uidsubset) { 1686 error = priv_check(td, PRIV_DEBUG_DIFFCRED); 1687 if (error) 1688 return (error); 1689 } 1690 1691 if (credentialchanged) { 1692 error = priv_check(td, PRIV_DEBUG_SUGID); 1693 if (error) 1694 return (error); 1695 } 1696 1697 /* Can't trace init when securelevel > 0. */ 1698 if (p == initproc) { 1699 error = securelevel_gt(td->td_ucred, 0); 1700 if (error) 1701 return (error); 1702 } 1703 1704 /* 1705 * Can't trace a process that's currently exec'ing. 1706 * 1707 * XXX: Note, this is not a security policy decision, it's a 1708 * basic correctness/functionality decision. Therefore, this check 1709 * should be moved to the caller's of p_candebug(). 1710 */ 1711 if ((p->p_flag & P_INEXEC) != 0) 1712 return (EBUSY); 1713 1714 /* Denied explicitely */ 1715 if ((p->p_flag2 & P2_NOTRACE) != 0) { 1716 error = priv_check(td, PRIV_DEBUG_DENIED); 1717 if (error != 0) 1718 return (error); 1719 } 1720 1721 return (0); 1722} 1723 1724/*- 1725 * Determine whether the subject represented by cred can "see" a socket. 1726 * Returns: 0 for permitted, ENOENT otherwise. 1727 */ 1728int 1729cr_canseesocket(struct ucred *cred, struct socket *so) 1730{ 1731 int error; 1732 1733 error = prison_check(cred, so->so_cred); 1734 if (error) 1735 return (ENOENT); 1736#ifdef MAC 1737 error = mac_socket_check_visible(cred, so); 1738 if (error) 1739 return (error); 1740#endif 1741 if (cr_seeotheruids(cred, so->so_cred)) 1742 return (ENOENT); 1743 if (cr_seeothergids(cred, so->so_cred)) 1744 return (ENOENT); 1745 1746 return (0); 1747} 1748 1749#if defined(INET) || defined(INET6) 1750/*- 1751 * Determine whether the subject represented by cred can "see" a socket. 1752 * Returns: 0 for permitted, ENOENT otherwise. 1753 */ 1754int 1755cr_canseeinpcb(struct ucred *cred, struct inpcb *inp) 1756{ 1757 int error; 1758 1759 error = prison_check(cred, inp->inp_cred); 1760 if (error) 1761 return (ENOENT); 1762#ifdef MAC 1763 INP_LOCK_ASSERT(inp); 1764 error = mac_inpcb_check_visible(cred, inp); 1765 if (error) 1766 return (error); 1767#endif 1768 if (cr_seeotheruids(cred, inp->inp_cred)) 1769 return (ENOENT); 1770 if (cr_seeothergids(cred, inp->inp_cred)) 1771 return (ENOENT); 1772 1773 return (0); 1774} 1775#endif 1776 1777/*- 1778 * Determine whether td can wait for the exit of p. 1779 * Returns: 0 for permitted, an errno value otherwise 1780 * Locks: Sufficient locks to protect various components of td and p 1781 * must be held. td must be curthread, and a lock must 1782 * be held for p. 1783 * References: td and p must be valid for the lifetime of the call 1784 1785 */ 1786int 1787p_canwait(struct thread *td, struct proc *p) 1788{ 1789 int error; 1790 1791 KASSERT(td == curthread, ("%s: td not curthread", __func__)); 1792 PROC_LOCK_ASSERT(p, MA_OWNED); 1793 if ((error = prison_check(td->td_ucred, p->p_ucred))) 1794 return (error); 1795#ifdef MAC 1796 if ((error = mac_proc_check_wait(td->td_ucred, p))) 1797 return (error); 1798#endif 1799#if 0 1800 /* XXXMAC: This could have odd effects on some shells. */ 1801 if ((error = cr_seeotheruids(td->td_ucred, p->p_ucred))) 1802 return (error); 1803#endif 1804 1805 return (0); 1806} 1807 1808/* 1809 * Allocate a zeroed cred structure. 1810 */ 1811struct ucred * 1812crget(void) 1813{ 1814 register struct ucred *cr; 1815 1816 cr = malloc(sizeof(*cr), M_CRED, M_WAITOK | M_ZERO); 1817 refcount_init(&cr->cr_ref, 1); 1818#ifdef AUDIT 1819 audit_cred_init(cr); 1820#endif 1821#ifdef MAC 1822 mac_cred_init(cr); 1823#endif 1824 crextend(cr, XU_NGROUPS); 1825 return (cr); 1826} 1827 1828/* 1829 * Claim another reference to a ucred structure. 1830 */ 1831struct ucred * 1832crhold(struct ucred *cr) 1833{ 1834 1835 refcount_acquire(&cr->cr_ref); 1836 return (cr); 1837} 1838 1839/* 1840 * Free a cred structure. Throws away space when ref count gets to 0. 1841 */ 1842void 1843crfree(struct ucred *cr) 1844{ 1845 1846 KASSERT(cr->cr_ref > 0, ("bad ucred refcount: %d", cr->cr_ref)); 1847 KASSERT(cr->cr_ref != 0xdeadc0de, ("dangling reference to ucred")); 1848 if (refcount_release(&cr->cr_ref)) { 1849 /* 1850 * Some callers of crget(), such as nfs_statfs(), 1851 * allocate a temporary credential, but don't 1852 * allocate a uidinfo structure. 1853 */ 1854 if (cr->cr_uidinfo != NULL) 1855 uifree(cr->cr_uidinfo); 1856 if (cr->cr_ruidinfo != NULL) 1857 uifree(cr->cr_ruidinfo); 1858 /* 1859 * Free a prison, if any. 1860 */ 1861 if (cr->cr_prison != NULL) 1862 prison_free(cr->cr_prison); 1863 if (cr->cr_loginclass != NULL) 1864 loginclass_free(cr->cr_loginclass); 1865#ifdef AUDIT 1866 audit_cred_destroy(cr); 1867#endif 1868#ifdef MAC 1869 mac_cred_destroy(cr); 1870#endif 1871 free(cr->cr_groups, M_CRED); 1872 free(cr, M_CRED); 1873 } 1874} 1875 1876/* 1877 * Check to see if this ucred is shared. 1878 */ 1879int 1880crshared(struct ucred *cr) 1881{ 1882 1883 return (cr->cr_ref > 1); 1884} 1885 1886/* 1887 * Copy a ucred's contents from a template. Does not block. 1888 */ 1889void 1890crcopy(struct ucred *dest, struct ucred *src) 1891{ 1892 1893 KASSERT(crshared(dest) == 0, ("crcopy of shared ucred")); 1894 bcopy(&src->cr_startcopy, &dest->cr_startcopy, 1895 (unsigned)((caddr_t)&src->cr_endcopy - 1896 (caddr_t)&src->cr_startcopy)); 1897 crsetgroups(dest, src->cr_ngroups, src->cr_groups); 1898 uihold(dest->cr_uidinfo); 1899 uihold(dest->cr_ruidinfo); 1900 prison_hold(dest->cr_prison); 1901 loginclass_hold(dest->cr_loginclass); 1902#ifdef AUDIT 1903 audit_cred_copy(src, dest); 1904#endif 1905#ifdef MAC 1906 mac_cred_copy(src, dest); 1907#endif 1908} 1909 1910/* 1911 * Dup cred struct to a new held one. 1912 */ 1913struct ucred * 1914crdup(struct ucred *cr) 1915{ 1916 struct ucred *newcr; 1917 1918 newcr = crget(); 1919 crcopy(newcr, cr); 1920 return (newcr); 1921} 1922 1923/* 1924 * Fill in a struct xucred based on a struct ucred. 1925 */ 1926void 1927cru2x(struct ucred *cr, struct xucred *xcr) 1928{ 1929 int ngroups; 1930 1931 bzero(xcr, sizeof(*xcr)); 1932 xcr->cr_version = XUCRED_VERSION; 1933 xcr->cr_uid = cr->cr_uid; 1934 1935 ngroups = MIN(cr->cr_ngroups, XU_NGROUPS); 1936 xcr->cr_ngroups = ngroups; 1937 bcopy(cr->cr_groups, xcr->cr_groups, 1938 ngroups * sizeof(*cr->cr_groups)); 1939} 1940 1941/* 1942 * small routine to swap a thread's current ucred for the correct one taken 1943 * from the process. 1944 */ 1945void 1946cred_update_thread(struct thread *td) 1947{ 1948 struct proc *p; 1949 struct ucred *cred; 1950 1951 p = td->td_proc; 1952 cred = td->td_ucred; 1953 PROC_LOCK(p); 1954 td->td_ucred = crhold(p->p_ucred); 1955 PROC_UNLOCK(p); 1956 if (cred != NULL) 1957 crfree(cred); 1958} 1959 1960struct ucred * 1961crcopysafe(struct proc *p, struct ucred *cr) 1962{ 1963 struct ucred *oldcred; 1964 int groups; 1965 1966 PROC_LOCK_ASSERT(p, MA_OWNED); 1967 1968 oldcred = p->p_ucred; 1969 while (cr->cr_agroups < oldcred->cr_agroups) { 1970 groups = oldcred->cr_agroups; 1971 PROC_UNLOCK(p); 1972 crextend(cr, groups); 1973 PROC_LOCK(p); 1974 oldcred = p->p_ucred; 1975 } 1976 crcopy(cr, oldcred); 1977 1978 return (oldcred); 1979} 1980 1981/* 1982 * Extend the passed in credential to hold n items. 1983 */ 1984static void 1985crextend(struct ucred *cr, int n) 1986{ 1987 int cnt; 1988 1989 /* Truncate? */ 1990 if (n <= cr->cr_agroups) 1991 return; 1992 1993 /* 1994 * We extend by 2 each time since we're using a power of two 1995 * allocator until we need enough groups to fill a page. 1996 * Once we're allocating multiple pages, only allocate as many 1997 * as we actually need. The case of processes needing a 1998 * non-power of two number of pages seems more likely than 1999 * a real world process that adds thousands of groups one at a 2000 * time. 2001 */ 2002 if ( n < PAGE_SIZE / sizeof(gid_t) ) { 2003 if (cr->cr_agroups == 0) 2004 cnt = MINALLOCSIZE / sizeof(gid_t); 2005 else 2006 cnt = cr->cr_agroups * 2; 2007 2008 while (cnt < n) 2009 cnt *= 2; 2010 } else 2011 cnt = roundup2(n, PAGE_SIZE / sizeof(gid_t)); 2012 2013 /* Free the old array. */ 2014 if (cr->cr_groups) 2015 free(cr->cr_groups, M_CRED); 2016 2017 cr->cr_groups = malloc(cnt * sizeof(gid_t), M_CRED, M_WAITOK | M_ZERO); 2018 cr->cr_agroups = cnt; 2019} 2020 2021/* 2022 * Copy groups in to a credential, preserving any necessary invariants. 2023 * Currently this includes the sorting of all supplemental gids. 2024 * crextend() must have been called before hand to ensure sufficient 2025 * space is available. 2026 */ 2027static void 2028crsetgroups_locked(struct ucred *cr, int ngrp, gid_t *groups) 2029{ 2030 int i; 2031 int j; 2032 gid_t g; 2033 2034 KASSERT(cr->cr_agroups >= ngrp, ("cr_ngroups is too small")); 2035 2036 bcopy(groups, cr->cr_groups, ngrp * sizeof(gid_t)); 2037 cr->cr_ngroups = ngrp; 2038 2039 /* 2040 * Sort all groups except cr_groups[0] to allow groupmember to 2041 * perform a binary search. 2042 * 2043 * XXX: If large numbers of groups become common this should 2044 * be replaced with shell sort like linux uses or possibly 2045 * heap sort. 2046 */ 2047 for (i = 2; i < ngrp; i++) { 2048 g = cr->cr_groups[i]; 2049 for (j = i-1; j >= 1 && g < cr->cr_groups[j]; j--) 2050 cr->cr_groups[j + 1] = cr->cr_groups[j]; 2051 cr->cr_groups[j + 1] = g; 2052 } 2053} 2054 2055/* 2056 * Copy groups in to a credential after expanding it if required. 2057 * Truncate the list to (ngroups_max + 1) if it is too large. 2058 */ 2059void 2060crsetgroups(struct ucred *cr, int ngrp, gid_t *groups) 2061{ 2062 2063 if (ngrp > ngroups_max + 1) 2064 ngrp = ngroups_max + 1; 2065 2066 crextend(cr, ngrp); 2067 crsetgroups_locked(cr, ngrp, groups); 2068} 2069 2070/* 2071 * Get login name, if available. 2072 */ 2073#ifndef _SYS_SYSPROTO_H_ 2074struct getlogin_args { 2075 char *namebuf; 2076 u_int namelen; 2077}; 2078#endif 2079/* ARGSUSED */ 2080int 2081sys_getlogin(struct thread *td, struct getlogin_args *uap) 2082{ 2083 char login[MAXLOGNAME]; 2084 struct proc *p = td->td_proc; 2085 size_t len; 2086 2087 if (uap->namelen > MAXLOGNAME) 2088 uap->namelen = MAXLOGNAME; 2089 PROC_LOCK(p); 2090 SESS_LOCK(p->p_session); 2091 len = strlcpy(login, p->p_session->s_login, uap->namelen) + 1; 2092 SESS_UNLOCK(p->p_session); 2093 PROC_UNLOCK(p); 2094 if (len > uap->namelen) 2095 return (ERANGE); 2096 return (copyout(login, uap->namebuf, len)); 2097} 2098 2099/* 2100 * Set login name. 2101 */ 2102#ifndef _SYS_SYSPROTO_H_ 2103struct setlogin_args { 2104 char *namebuf; 2105}; 2106#endif 2107/* ARGSUSED */ 2108int 2109sys_setlogin(struct thread *td, struct setlogin_args *uap) 2110{ 2111 struct proc *p = td->td_proc; 2112 int error; 2113 char logintmp[MAXLOGNAME]; 2114 2115 CTASSERT(sizeof(p->p_session->s_login) >= sizeof(logintmp)); 2116 2117 error = priv_check(td, PRIV_PROC_SETLOGIN); 2118 if (error) 2119 return (error); 2120 error = copyinstr(uap->namebuf, logintmp, sizeof(logintmp), NULL); 2121 if (error != 0) { 2122 if (error == ENAMETOOLONG) 2123 error = EINVAL; 2124 return (error); 2125 } 2126 PROC_LOCK(p); 2127 SESS_LOCK(p->p_session); 2128 strcpy(p->p_session->s_login, logintmp); 2129 SESS_UNLOCK(p->p_session); 2130 PROC_UNLOCK(p); 2131 return (0); 2132} 2133 2134void 2135setsugid(struct proc *p) 2136{ 2137 2138 PROC_LOCK_ASSERT(p, MA_OWNED); 2139 p->p_flag |= P_SUGID; 2140 if (!(p->p_pfsflags & PF_ISUGID)) 2141 p->p_stops = 0; 2142} 2143 2144/*- 2145 * Change a process's effective uid. 2146 * Side effects: newcred->cr_uid and newcred->cr_uidinfo will be modified. 2147 * References: newcred must be an exclusive credential reference for the 2148 * duration of the call. 2149 */ 2150void 2151change_euid(struct ucred *newcred, struct uidinfo *euip) 2152{ 2153 2154 newcred->cr_uid = euip->ui_uid; 2155 uihold(euip); 2156 uifree(newcred->cr_uidinfo); 2157 newcred->cr_uidinfo = euip; 2158} 2159 2160/*- 2161 * Change a process's effective gid. 2162 * Side effects: newcred->cr_gid will be modified. 2163 * References: newcred must be an exclusive credential reference for the 2164 * duration of the call. 2165 */ 2166void 2167change_egid(struct ucred *newcred, gid_t egid) 2168{ 2169 2170 newcred->cr_groups[0] = egid; 2171} 2172 2173/*- 2174 * Change a process's real uid. 2175 * Side effects: newcred->cr_ruid will be updated, newcred->cr_ruidinfo 2176 * will be updated, and the old and new cr_ruidinfo proc 2177 * counts will be updated. 2178 * References: newcred must be an exclusive credential reference for the 2179 * duration of the call. 2180 */ 2181void 2182change_ruid(struct ucred *newcred, struct uidinfo *ruip) 2183{ 2184 2185 (void)chgproccnt(newcred->cr_ruidinfo, -1, 0); 2186 newcred->cr_ruid = ruip->ui_uid; 2187 uihold(ruip); 2188 uifree(newcred->cr_ruidinfo); 2189 newcred->cr_ruidinfo = ruip; 2190 (void)chgproccnt(newcred->cr_ruidinfo, 1, 0); 2191} 2192 2193/*- 2194 * Change a process's real gid. 2195 * Side effects: newcred->cr_rgid will be updated. 2196 * References: newcred must be an exclusive credential reference for the 2197 * duration of the call. 2198 */ 2199void 2200change_rgid(struct ucred *newcred, gid_t rgid) 2201{ 2202 2203 newcred->cr_rgid = rgid; 2204} 2205 2206/*- 2207 * Change a process's saved uid. 2208 * Side effects: newcred->cr_svuid will be updated. 2209 * References: newcred must be an exclusive credential reference for the 2210 * duration of the call. 2211 */ 2212void 2213change_svuid(struct ucred *newcred, uid_t svuid) 2214{ 2215 2216 newcred->cr_svuid = svuid; 2217} 2218 2219/*- 2220 * Change a process's saved gid. 2221 * Side effects: newcred->cr_svgid will be updated. 2222 * References: newcred must be an exclusive credential reference for the 2223 * duration of the call. 2224 */ 2225void 2226change_svgid(struct ucred *newcred, gid_t svgid) 2227{ 2228 2229 newcred->cr_svgid = svgid; 2230} 2231