security/mac_process.c

   1 /*
   2  * Copyright (c) 2007-2010 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /*-
  30  * Copyright (c) 1999, 2000, 2001, 2002 Robert N. M. Watson
  31  * Copyright (c) 2001 Ilmar S. Habibulin
  32  * Copyright (c) 2001, 2002, 2003, 2004 Networks Associates Technology, Inc.
  33  *
  34  * This software was developed by Robert Watson and Ilmar Habibulin for the
  35  * TrustedBSD Project.
  36  *
  37  * This software was developed for the FreeBSD Project in part by Network
  38  * Associates Laboratories, the Security Research Division of Network
  39  * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
  40  * as part of the DARPA CHATS research program.
  41  *
  42  * Redistribution and use in source and binary forms, with or without
  43  * modification, are permitted provided that the following conditions
  44  * are met:
  45  * 1. Redistributions of source code must retain the above copyright
  46  *    notice, this list of conditions and the following disclaimer.
  47  * 2. Redistributions in binary form must reproduce the above copyright
  48  *    notice, this list of conditions and the following disclaimer in the
  49  *    documentation and/or other materials provided with the distribution.
  50  *
  51  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  61  * SUCH DAMAGE.
  62  *
  63  */
  64
  65 #include <string.h>
  66 #include <sys/param.h>
  67 #include <sys/ucred.h>
  68 #include <sys/malloc.h>
  69 #include <sys/sbuf.h>
  70 #include <sys/vnode.h>
  71 #include <sys/proc.h>
  72 #include <sys/proc_internal.h>
  73 #include <sys/kauth.h>
  74 #include <sys/imgact.h>
  75
  76 #include <security/mac_internal.h>
  77
  78 #include <bsd/security/audit/audit.h>
  79
  80 struct label *
  81 mac_cred_label_alloc(void)
  82 {
  83         struct label *label;
  84
  85         label = mac_labelzone_alloc(MAC_WAITOK);
  86         if (label == NULL)
  87                 return (NULL);
  88         MAC_PERFORM(cred_label_init, label);
  89         return (label);
  90 }
  91
  92 void
  93 mac_cred_label_init(struct ucred *cred)
  94 {
  95         cred->cr_label = mac_cred_label_alloc();
  96 }
  97
  98 void
  99 mac_cred_label_free(struct label *label)
 100 {
 101         MAC_PERFORM(cred_label_destroy, label);
 102         mac_labelzone_free(label);
 103 }
 104
 105 int
 106 mac_cred_label_externalize_audit(struct proc *p, struct mac *mac)
 107 {
 108         kauth_cred_t cr;
 109         int error;
 110
 111         cr = kauth_cred_proc_ref(p);
 112
 113         error = MAC_EXTERNALIZE_AUDIT(cred, cr->cr_label,
 114             mac->m_string, mac->m_buflen);
 115
 116         kauth_cred_unref(&cr);
 117         return (error);
 118 }
 119
 120 void
 121 mac_cred_label_destroy(kauth_cred_t cred)
 122 {
 123
 124         mac_cred_label_free(cred->cr_label);
 125         cred->cr_label = NULL;
 126 }
 127
 128 int
 129 mac_cred_label_externalize(struct label *label, char *elements,
 130     char *outbuf, size_t outbuflen, int flags __unused)
 131 {
 132         int error = 0;
 133
 134         error = MAC_EXTERNALIZE(cred, label, elements, outbuf, outbuflen);
 135
 136         return (error);
 137 }
 138
 139 int
 140 mac_cred_label_internalize(struct label *label, char *string)
 141 {
 142         int error;
 143
 144         error = MAC_INTERNALIZE(cred, label, string);
 145
 146         return (error);
 147 }
 148
 149 /*
 150  * By default, fork just adds a reference to the parent
 151  * credential.  Policies may need to know about this reference
 152  * if they are tracking exit calls to know when to free the
 153  * label.
 154  */
 155 void
 156 mac_cred_label_associate_fork(kauth_cred_t cred, proc_t proc)
 157 {
 158         MAC_PERFORM(cred_label_associate_fork, cred, proc);
 159 }
 160
 161 /*
 162  * Initialize MAC label for the first kernel process, from which other
 163  * kernel processes and threads are spawned.
 164  */
 165 void
 166 mac_cred_label_associate_kernel(kauth_cred_t cred)
 167 {
 168
 169         MAC_PERFORM(cred_label_associate_kernel, cred);
 170 }
 171
 172 /*
 173  * Initialize MAC label for the first userland process, from which other
 174  * userland processes and threads are spawned.
 175  */
 176 void
 177 mac_cred_label_associate_user(kauth_cred_t cred)
 178 {
 179
 180         MAC_PERFORM(cred_label_associate_user, cred);
 181 }
 182
 183 /*
 184  * When a new process is created, its label must be initialized.  Generally,
 185  * this involves inheritence from the parent process, modulo possible
 186  * deltas.  This function allows that processing to take place.
 187  */
 188 void
 189 mac_cred_label_associate(struct ucred *parent_cred, struct ucred *child_cred)
 190 {
 191
 192         MAC_PERFORM(cred_label_associate, parent_cred, child_cred);
 193 }
 194
 195 int
 196 mac_execve_enter(user_addr_t mac_p, struct image_params *imgp)
 197 {
 198         struct user_mac mac;
 199         struct label *execlabel;
 200         char *buffer;
 201         int error;
 202         size_t ulen;
 203
 204         if (mac_p == USER_ADDR_NULL)
 205                 return (0);
 206
 207         if (IS_64BIT_PROCESS(current_proc())) {
 208                 struct user64_mac mac64;
 209                 error = copyin(mac_p, &mac64, sizeof(mac64));
 210                 mac.m_buflen = mac64.m_buflen;
 211                 mac.m_string = mac64.m_string;
 212         } else {
 213                 struct user32_mac mac32;
 214                 error = copyin(mac_p, &mac32, sizeof(mac32));
 215                 mac.m_buflen = mac32.m_buflen;
 216                 mac.m_string = mac32.m_string;
 217         }
 218         if (error)
 219                 return (error);
 220
 221         error = mac_check_structmac_consistent(&mac);
 222         if (error)
 223                 return (error);
 224
 225         execlabel = mac_cred_label_alloc();
 226         MALLOC(buffer, char *, mac.m_buflen, M_MACTEMP, M_WAITOK);
 227         error = copyinstr(CAST_USER_ADDR_T(mac.m_string), buffer, mac.m_buflen, &ulen);
 228         if (error)
 229                 goto out;
 230         AUDIT_ARG(mac_string, buffer);
 231
 232         error = mac_cred_label_internalize(execlabel, buffer);
 233 out:
 234         if (error) {
 235                 mac_cred_label_free(execlabel);
 236                 execlabel = NULL;
 237         }
 238         imgp->ip_execlabelp = execlabel;
 239         FREE(buffer, M_MACTEMP);
 240         return (error);
 241 }
 242
 243 /*
 244  * When the subject's label changes, it may require revocation of privilege
 245  * to mapped objects.  This can't be done on-the-fly later with a unified
 246  * buffer cache.
 247  *
 248  * XXX:         CRF_MAC_ENFORCE should be in a kauth_cred_t field, rather
 249  * XXX:         than a posix_cred_t field.
 250  */
 251 void
 252 mac_cred_label_update(kauth_cred_t cred, struct label *newlabel)
 253 {
 254         posix_cred_t pcred = posix_cred_get(cred);
 255
 256         /* force label to be part of "matching" for credential */
 257         pcred->cr_flags |= CRF_MAC_ENFORCE;
 258
 259         /* inform the policies of the update */
 260         MAC_PERFORM(cred_label_update, cred, newlabel);
 261 }
 262
 263 int
 264 mac_cred_check_label_update(kauth_cred_t cred, struct label *newlabel)
 265 {
 266         int error;
 267
 268         if (!mac_proc_enforce)
 269                 return (0);
 270
 271         MAC_CHECK(cred_check_label_update, cred, newlabel);
 272
 273         return (error);
 274 }
 275
 276 int
 277 mac_cred_check_visible(kauth_cred_t u1, kauth_cred_t u2)
 278 {
 279         int error;
 280
 281
 282
 283         if (!mac_proc_enforce)
 284                 return (0);
 285
 286
 287
 288         MAC_CHECK(cred_check_visible, u1, u2);
 289
 290
 291         return (error);
 292 }
 293
 294 /*
 295  * called with process locked.
 296  */
 297 void mac_proc_set_enforce(proc_t p, int enforce_flags)
 298 {
 299         p->p_mac_enforce |= enforce_flags;
 300 }
 301
 302 int
 303 mac_proc_check_debug(proc_t curp, struct proc *proc)
 304 {
 305         kauth_cred_t cred;
 306         int error;
 307
 308
 309
 310         if (!mac_proc_enforce ||
 311             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 312                 return (0);
 313
 314         cred = kauth_cred_proc_ref(curp);
 315         MAC_CHECK(proc_check_debug, cred, proc);
 316         kauth_cred_unref(&cred);
 317
 318         return (error);
 319 }
 320
 321 int
 322 mac_proc_check_fork(proc_t curp)
 323 {
 324         kauth_cred_t cred;
 325         int error;
 326
 327         if (!mac_proc_enforce ||
 328             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 329                 return (0);
 330
 331         cred = kauth_cred_proc_ref(curp);
 332         MAC_CHECK(proc_check_fork, cred, curp);
 333         kauth_cred_unref(&cred);
 334
 335         return (error);
 336 }
 337
 338 int
 339 mac_proc_check_get_task_name(struct ucred *cred, struct proc *p)
 340 {
 341         int error;
 342
 343         MAC_CHECK(proc_check_get_task_name, cred, p);
 344
 345         return (error);
 346 }
 347
 348 int
 349 mac_proc_check_get_task(struct ucred *cred, struct proc *p)
 350 {
 351         int error;
 352
 353         MAC_CHECK(proc_check_get_task, cred, p);
 354
 355         return (error);
 356 }
 357
 358 /*
 359  * The type of maxprot in proc_check_map_anon must be equivalent to vm_prot_t
 360  * (defined in <mach/vm_prot.h>). mac_policy.h does not include any header
 361  * files, so cannot use the typedef itself.
 362  */
 363 int
 364 mac_proc_check_map_anon(proc_t proc, user_addr_t u_addr,
 365     user_size_t u_size, int prot, int flags, int *maxprot)
 366 {
 367         kauth_cred_t cred;
 368         int error;
 369
 370         if (!mac_vm_enforce ||
 371             !mac_proc_check_enforce(proc, MAC_VM_ENFORCE))
 372                 return (0);
 373
 374         cred = kauth_cred_proc_ref(proc);
 375         MAC_CHECK(proc_check_map_anon, proc, cred, u_addr, u_size, prot, flags, maxprot);
 376         kauth_cred_unref(&cred);
 377
 378         return (error);
 379 }
 380
 381 int
 382 mac_proc_check_mprotect(proc_t proc,
 383     user_addr_t addr, user_size_t size, int prot)
 384 {
 385         kauth_cred_t cred;
 386         int error;
 387
 388         if (!mac_vm_enforce ||
 389             !mac_proc_check_enforce(proc, MAC_VM_ENFORCE))
 390                 return (0);
 391
 392         cred = kauth_cred_proc_ref(proc);
 393         MAC_CHECK(proc_check_mprotect, cred, proc, addr, size, prot);
 394         kauth_cred_unref(&cred);
 395
 396         return (error);
 397 }
 398
 399 int
 400 mac_proc_check_run_cs_invalid(proc_t proc)
 401 {
 402         int error;
 403
 404         if (!mac_vm_enforce) return (0);
 405
 406         MAC_CHECK(proc_check_run_cs_invalid, proc);
 407
 408         return (error);
 409 }
 410
 411 int
 412 mac_proc_check_sched(proc_t curp, struct proc *proc)
 413 {
 414         kauth_cred_t cred;
 415         int error;
 416
 417
 418
 419         if (!mac_proc_enforce ||
 420             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 421                 return (0);
 422
 423         cred = kauth_cred_proc_ref(curp);
 424         MAC_CHECK(proc_check_sched, cred, proc);
 425         kauth_cred_unref(&cred);
 426
 427         return (error);
 428 }
 429
 430 int
 431 mac_proc_check_signal(proc_t curp, struct proc *proc, int signum)
 432 {
 433         kauth_cred_t cred;
 434         int error;
 435
 436
 437
 438         if (!mac_proc_enforce ||
 439             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 440                 return (0);
 441
 442         cred = kauth_cred_proc_ref(curp);
 443         MAC_CHECK(proc_check_signal, cred, proc, signum);
 444         kauth_cred_unref(&cred);
 445
 446         return (error);
 447 }
 448
 449 int
 450 mac_proc_check_wait(proc_t curp, struct proc *proc)
 451 {
 452         kauth_cred_t cred;
 453         int error;
 454
 455
 456
 457         if (!mac_proc_enforce ||
 458             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 459                 return (0);
 460
 461         cred = kauth_cred_proc_ref(curp);
 462         MAC_CHECK(proc_check_wait, cred, proc);
 463         kauth_cred_unref(&cred);
 464
 465         return (error);
 466 }
 467
 468 #if CONFIG_LCTX
 469 /*
 470  * Login Context
 471  */
 472
 473 int
 474 mac_proc_check_setlcid (struct proc *p0, struct proc *p,
 475                         pid_t pid, pid_t lcid)
 476 {
 477         int error;
 478
 479         if (!mac_proc_enforce ||
 480             !mac_proc_check_enforce(p0, MAC_PROC_ENFORCE))
 481                 return (0);
 482
 483         MAC_CHECK(proc_check_setlcid, p0, p, pid, lcid);
 484         return (error);
 485 }
 486
 487 int
 488 mac_proc_check_getlcid (struct proc *p0, struct proc *p, pid_t pid)
 489 {
 490         int error;
 491
 492         if (!mac_proc_enforce ||
 493             !mac_proc_check_enforce(p0, MAC_PROC_ENFORCE))
 494                 return (0);
 495
 496         MAC_CHECK(proc_check_getlcid, p0, p, pid);
 497         return (error);
 498 }
 499
 500 void
 501 mac_lctx_notify_create (struct proc *p, struct lctx *l)
 502 {
 503         MAC_PERFORM(lctx_notify_create, p, l);
 504 }
 505
 506 void
 507 mac_lctx_notify_join (struct proc *p, struct lctx *l)
 508 {
 509         MAC_PERFORM(lctx_notify_join, p, l);
 510 }
 511
 512 void
 513 mac_lctx_notify_leave (struct proc *p, struct lctx *l)
 514 {
 515         MAC_PERFORM(lctx_notify_leave, p, l);
 516 }
 517
 518 struct label *
 519 mac_lctx_label_alloc(void)
 520 {
 521         struct label *label;
 522
 523         label = mac_labelzone_alloc(MAC_WAITOK);
 524         if (label == NULL)
 525                 return (NULL);
 526         MAC_PERFORM(lctx_label_init, label);
 527         return (label);
 528 }
 529
 530 void
 531 mac_lctx_label_free(struct label *label)
 532 {
 533
 534         MAC_PERFORM(lctx_label_destroy, label);
 535         mac_labelzone_free(label);
 536 }
 537
 538 int
 539 mac_lctx_label_externalize(struct label *label, char *elements,
 540     char *outbuf, size_t outbuflen)
 541 {
 542         int error;
 543
 544         error = MAC_EXTERNALIZE(lctx, label, elements, outbuf, outbuflen);
 545
 546         return (error);
 547 }
 548
 549 int
 550 mac_lctx_label_internalize(struct label *label, char *string)
 551 {
 552         int error;
 553
 554         error = MAC_INTERNALIZE(lctx, label, string);
 555
 556         return (error);
 557 }
 558
 559 void
 560 mac_lctx_label_update(struct lctx *l, struct label *newlabel)
 561 {
 562
 563         MAC_PERFORM(lctx_label_update, l, newlabel);
 564 }
 565
 566 int
 567 mac_lctx_check_label_update(struct lctx *l, struct label *newlabel)
 568 {
 569         int error;
 570
 571         MAC_CHECK(lctx_check_label_update, l, newlabel);
 572
 573         return (error);
 574 }
 575 #endif  /* LCTX */
 576
 577 int
 578 mac_proc_check_suspend_resume(proc_t curp, int sr)
 579 {
 580         kauth_cred_t cred;
 581         int error;
 582
 583         if (!mac_proc_enforce ||
 584             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 585                 return (0);
 586
 587         cred = kauth_cred_proc_ref(curp);
 588         MAC_CHECK(proc_check_suspend_resume, cred, curp, sr);
 589         kauth_cred_unref(&cred);
 590
 591         return (error);
 592 }