security/mac_process.c

   1 /*
   2  * Copyright (c) 2007 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                 error = copyin(mac_p, &mac, sizeof(mac));
 209         } else {
 210                 struct mac mac32;
 211                 error = copyin(mac_p, &mac32, sizeof(mac32));
 212                 mac.m_buflen = mac32.m_buflen;
 213                 mac.m_string = CAST_USER_ADDR_T(mac32.m_string);
 214         }
 215         if (error)
 216                 return (error);
 217
 218         error = mac_check_structmac_consistent(&mac);
 219         if (error)
 220                 return (error);
 221
 222         execlabel = mac_cred_label_alloc();
 223         MALLOC(buffer, char *, mac.m_buflen, M_MACTEMP, M_WAITOK);
 224         error = copyinstr(CAST_USER_ADDR_T(mac.m_string), buffer, mac.m_buflen, &ulen);
 225         if (error)
 226                 goto out;
 227         AUDIT_ARG(mac_string, buffer);
 228
 229         error = mac_cred_label_internalize(execlabel, buffer);
 230 out:
 231         if (error) {
 232                 mac_cred_label_free(execlabel);
 233                 execlabel = NULL;
 234         }
 235         imgp->ip_execlabelp = execlabel;
 236         FREE(buffer, M_MACTEMP);
 237         return (error);
 238 }
 239
 240 /*
 241  * When the subject's label changes, it may require revocation of privilege
 242  * to mapped objects.  This can't be done on-the-fly later with a unified
 243  * buffer cache.
 244  */
 245 void
 246 mac_cred_label_update(kauth_cred_t cred, struct label *newlabel)
 247 {
 248
 249         /* force label to be part of "matching" for credential */
 250         cred->cr_flags |= CRF_MAC_ENFORCE;
 251
 252         /* inform the policies of the update */
 253         MAC_PERFORM(cred_label_update, cred, newlabel);
 254 }
 255
 256 int
 257 mac_cred_check_label_update(kauth_cred_t cred, struct label *newlabel)
 258 {
 259         int error;
 260
 261         if (!mac_proc_enforce)
 262                 return (0);
 263
 264         MAC_CHECK(cred_check_label_update, cred, newlabel);
 265
 266         return (error);
 267 }
 268
 269 int
 270 mac_cred_check_visible(kauth_cred_t u1, kauth_cred_t u2)
 271 {
 272         int error;
 273
 274
 275
 276         if (!mac_proc_enforce)
 277                 return (0);
 278
 279
 280
 281         MAC_CHECK(cred_check_visible, u1, u2);
 282
 283
 284         return (error);
 285 }
 286
 287 /*
 288  * called with process locked.
 289  */
 290 void mac_proc_set_enforce(proc_t p, int enforce_flags)
 291 {
 292         p->p_mac_enforce |= enforce_flags;
 293 }
 294
 295 int
 296 mac_proc_check_debug(proc_t curp, struct proc *proc)
 297 {
 298         kauth_cred_t cred;
 299         int error;
 300
 301
 302
 303         if (!mac_proc_enforce ||
 304             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 305                 return (0);
 306
 307         cred = kauth_cred_proc_ref(curp);
 308         MAC_CHECK(proc_check_debug, cred, proc);
 309         kauth_cred_unref(&cred);
 310
 311         return (error);
 312 }
 313
 314 int
 315 mac_proc_check_fork(proc_t curp)
 316 {
 317         kauth_cred_t cred;
 318         int error;
 319
 320         if (!mac_proc_enforce ||
 321             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 322                 return (0);
 323
 324         cred = kauth_cred_proc_ref(curp);
 325         MAC_CHECK(proc_check_fork, cred, curp);
 326         kauth_cred_unref(&cred);
 327
 328         return (error);
 329 }
 330
 331 int
 332 mac_proc_check_get_task_name(struct ucred *cred, struct proc *p)
 333 {
 334         int error;
 335
 336         MAC_CHECK(proc_check_get_task_name, cred, p);
 337
 338         return (error);
 339 }
 340
 341 int
 342 mac_proc_check_get_task(struct ucred *cred, struct proc *p)
 343 {
 344         int error;
 345
 346         MAC_CHECK(proc_check_get_task, cred, p);
 347
 348         return (error);
 349 }
 350
 351 int
 352 mac_proc_check_mprotect(proc_t proc,
 353     user_addr_t addr, user_size_t size, int prot)
 354 {
 355         kauth_cred_t cred;
 356         int error;
 357
 358         if (!mac_vm_enforce ||
 359             !mac_proc_check_enforce(proc, MAC_VM_ENFORCE))
 360                 return (0);
 361
 362         cred = kauth_cred_proc_ref(proc);
 363         MAC_CHECK(proc_check_mprotect, cred, proc, addr, size, prot);
 364         kauth_cred_unref(&cred);
 365
 366         return (error);
 367 }
 368
 369 int
 370 mac_proc_check_run_cs_invalid(proc_t proc)
 371 {
 372         int error;
 373
 374         if (!mac_vm_enforce) return (0);
 375
 376         MAC_CHECK(proc_check_run_cs_invalid, proc);
 377
 378         return (error);
 379 }
 380
 381 int
 382 mac_proc_check_sched(proc_t curp, struct proc *proc)
 383 {
 384         kauth_cred_t cred;
 385         int error;
 386
 387
 388
 389         if (!mac_proc_enforce ||
 390             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 391                 return (0);
 392
 393         cred = kauth_cred_proc_ref(curp);
 394         MAC_CHECK(proc_check_sched, cred, proc);
 395         kauth_cred_unref(&cred);
 396
 397         return (error);
 398 }
 399
 400 int
 401 mac_proc_check_signal(proc_t curp, struct proc *proc, int signum)
 402 {
 403         kauth_cred_t cred;
 404         int error;
 405
 406
 407
 408         if (!mac_proc_enforce ||
 409             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 410                 return (0);
 411
 412         cred = kauth_cred_proc_ref(curp);
 413         MAC_CHECK(proc_check_signal, cred, proc, signum);
 414         kauth_cred_unref(&cred);
 415
 416         return (error);
 417 }
 418
 419 int
 420 mac_proc_check_wait(proc_t curp, struct proc *proc)
 421 {
 422         kauth_cred_t cred;
 423         int error;
 424
 425
 426
 427         if (!mac_proc_enforce ||
 428             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 429                 return (0);
 430
 431         cred = kauth_cred_proc_ref(curp);
 432         MAC_CHECK(proc_check_wait, cred, proc);
 433         kauth_cred_unref(&cred);
 434
 435         return (error);
 436 }
 437
 438 #if CONFIG_LCTX
 439 /*
 440  * Login Context
 441  */
 442
 443 int
 444 mac_proc_check_setlcid (struct proc *p0, struct proc *p,
 445                         pid_t pid, pid_t lcid)
 446 {
 447         int error;
 448
 449         if (!mac_proc_enforce ||
 450             !mac_proc_check_enforce(p0, MAC_PROC_ENFORCE))
 451                 return (0);
 452
 453         MAC_CHECK(proc_check_setlcid, p0, p, pid, lcid);
 454         return (error);
 455 }
 456
 457 int
 458 mac_proc_check_getlcid (struct proc *p0, struct proc *p, pid_t pid)
 459 {
 460         int error;
 461
 462         if (!mac_proc_enforce ||
 463             !mac_proc_check_enforce(p0, MAC_PROC_ENFORCE))
 464                 return (0);
 465
 466         MAC_CHECK(proc_check_getlcid, p0, p, pid);
 467         return (error);
 468 }
 469
 470 void
 471 mac_lctx_notify_create (struct proc *p, struct lctx *l)
 472 {
 473         MAC_PERFORM(lctx_notify_create, p, l);
 474 }
 475
 476 void
 477 mac_lctx_notify_join (struct proc *p, struct lctx *l)
 478 {
 479         MAC_PERFORM(lctx_notify_join, p, l);
 480 }
 481
 482 void
 483 mac_lctx_notify_leave (struct proc *p, struct lctx *l)
 484 {
 485         MAC_PERFORM(lctx_notify_leave, p, l);
 486 }
 487
 488 struct label *
 489 mac_lctx_label_alloc(void)
 490 {
 491         struct label *label;
 492
 493         label = mac_labelzone_alloc(MAC_WAITOK);
 494         if (label == NULL)
 495                 return (NULL);
 496         MAC_PERFORM(lctx_label_init, label);
 497         return (label);
 498 }
 499
 500 void
 501 mac_lctx_label_free(struct label *label)
 502 {
 503
 504         MAC_PERFORM(lctx_label_destroy, label);
 505         mac_labelzone_free(label);
 506 }
 507
 508 int
 509 mac_lctx_label_externalize(struct label *label, char *elements,
 510     char *outbuf, size_t outbuflen)
 511 {
 512         int error;
 513
 514         error = MAC_EXTERNALIZE(lctx, label, elements, outbuf, outbuflen);
 515
 516         return (error);
 517 }
 518
 519 int
 520 mac_lctx_label_internalize(struct label *label, char *string)
 521 {
 522         int error;
 523
 524         error = MAC_INTERNALIZE(lctx, label, string);
 525
 526         return (error);
 527 }
 528
 529 void
 530 mac_lctx_label_update(struct lctx *l, struct label *newlabel)
 531 {
 532
 533         MAC_PERFORM(lctx_label_update, l, newlabel);
 534 }
 535
 536 int
 537 mac_lctx_check_label_update(struct lctx *l, struct label *newlabel)
 538 {
 539         int error;
 540
 541         MAC_CHECK(lctx_check_label_update, l, newlabel);
 542
 543         return (error);
 544 }
 545 #endif  /* LCTX */
 546
 547
 548 void
 549 mac_thread_userret(int code, int error, struct thread *thread)
 550 {
 551
 552         if (mac_late)
 553                 MAC_PERFORM(thread_userret, code, error, thread);
 554 }