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