1/*-
2 * Copyright (c) 1999-2002 Robert N. M. Watson
3 * Copyright (c) 2001 Ilmar S. Habibulin
4 * Copyright (c) 2001-2003 Networks Associates Technology, Inc.
5 * Copyright (c) 2005 Samy Al Bahra
6 * Copyright (c) 2006 SPARTA, Inc.
7 * All rights reserved.
8 *
9 * This software was developed by Robert Watson and Ilmar Habibulin for the
10 * TrustedBSD Project.
11 *
12 * This software was developed for the FreeBSD Project in part by Network
13 * Associates Laboratories, the Security Research Division of Network
14 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
15 * as part of the DARPA CHATS research program.
16 *
17 * This software was enhanced by SPARTA ISSO under SPAWAR contract
18 * N66001-04-C-6019 ("SEFOS").
19 *
20 * Redistribution and use in source and binary forms, with or without
21 * modification, are permitted provided that the following conditions
22 * are met:
23 * 1. Redistributions of source code must retain the above copyright
24 * notice, this list of conditions and the following disclaimer.
25 * 2. Redistributions in binary form must reproduce the above copyright
26 * notice, this list of conditions and the following disclaimer in the
27 * documentation and/or other materials provided with the distribution.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * SUCH DAMAGE.
40 */
41
42#include <sys/cdefs.h>
43__FBSDID("$FreeBSD: head/sys/security/mac/mac_process.c 172930 2007-10-24 19:04:04Z rwatson $");
44
45#include "opt_mac.h"
46
47#include <sys/param.h>
48#include <sys/condvar.h>
49#include <sys/imgact.h>
50#include <sys/kernel.h>
51#include <sys/lock.h>
52#include <sys/malloc.h>
53#include <sys/mutex.h>
54#include <sys/mac.h>
55#include <sys/proc.h>
56#include <sys/sbuf.h>
57#include <sys/systm.h>
58#include <sys/vnode.h>
59#include <sys/mount.h>
60#include <sys/file.h>
61#include <sys/namei.h>
62#include <sys/sysctl.h>
63
64#include <vm/vm.h>
65#include <vm/pmap.h>
66#include <vm/vm_map.h>
67#include <vm/vm_object.h>
68
69#include <security/mac/mac_framework.h>
70#include <security/mac/mac_internal.h>
71#include <security/mac/mac_policy.h>
72
73static int mac_mmap_revocation = 1;
74SYSCTL_INT(_security_mac, OID_AUTO, mmap_revocation, CTLFLAG_RW,
75 &mac_mmap_revocation, 0, "Revoke mmap access to files on subject "
76 "relabel");
77
78static int mac_mmap_revocation_via_cow = 0;
79SYSCTL_INT(_security_mac, OID_AUTO, mmap_revocation_via_cow, CTLFLAG_RW,
80 &mac_mmap_revocation_via_cow, 0, "Revoke mmap access to files via "
81 "copy-on-write semantics, or by removing all write access");
82
83static void mac_cred_mmapped_drop_perms_recurse(struct thread *td,
84 struct ucred *cred, struct vm_map *map);
85
86struct label *
87mac_cred_label_alloc(void)
88{
89 struct label *label;
90
91 label = mac_labelzone_alloc(M_WAITOK);
92 MAC_PERFORM(cred_init_label, label);
93 return (label);
94}
95
96void
97mac_cred_init(struct ucred *cred)
98{
99
100 cred->cr_label = mac_cred_label_alloc();
101}
102
103static struct label *
104mac_proc_label_alloc(void)
105{
106 struct label *label;
107
108 label = mac_labelzone_alloc(M_WAITOK);
109 MAC_PERFORM(proc_init_label, label);
110 return (label);
111}
112
113void
114mac_proc_init(struct proc *p)
115{
116
117 p->p_label = mac_proc_label_alloc();
118}
119
120void
121mac_cred_label_free(struct label *label)
122{
123
124 MAC_PERFORM(cred_destroy_label, label);
125 mac_labelzone_free(label);
126}
127
128void
129mac_cred_destroy(struct ucred *cred)
130{
131
132 mac_cred_label_free(cred->cr_label);
133 cred->cr_label = NULL;
134}
135
136static void
137mac_proc_label_free(struct label *label)
138{
139
140 MAC_PERFORM(proc_destroy_label, label);
141 mac_labelzone_free(label);
142}
143
144void
145mac_proc_destroy(struct proc *p)
146{
147
148 mac_proc_label_free(p->p_label);
149 p->p_label = NULL;
150}
151
152int
153mac_cred_externalize_label(struct label *label, char *elements,
154 char *outbuf, size_t outbuflen)
155{
156 int error;
157
158 MAC_EXTERNALIZE(cred, label, elements, outbuf, outbuflen);
159
160 return (error);
161}
162
163int
164mac_cred_internalize_label(struct label *label, char *string)
165{
166 int error;
167
168 MAC_INTERNALIZE(cred, label, string);
169
170 return (error);
171}
172
173/*
174 * Initialize MAC label for the first kernel process, from which other kernel
175 * processes and threads are spawned.
176 */
177void
178mac_proc_create_swapper(struct ucred *cred)
179{
180
181 MAC_PERFORM(proc_create_swapper, cred);
182}
183
184/*
185 * Initialize MAC label for the first userland process, from which other
186 * userland processes and threads are spawned.
187 */
188void
189mac_proc_create_init(struct ucred *cred)
190{
191
192 MAC_PERFORM(proc_create_init, cred);
193}
194
195void
196mac_thread_userret(struct thread *td)
197{
198
199 MAC_PERFORM(thread_userret, td);
200}
201
202/*
203 * When a new process is created, its label must be initialized. Generally,
204 * this involves inheritence from the parent process, modulo possible deltas.
205 * This function allows that processing to take place.
206 */
207void
208mac_cred_copy(struct ucred *src, struct ucred *dest)
209{
210
211 MAC_PERFORM(cred_copy_label, src->cr_label, dest->cr_label);
212}
213
214int
215mac_execve_enter(struct image_params *imgp, struct mac *mac_p)
216{
217 struct label *label;
218 struct mac mac;
219 char *buffer;
220 int error;
221
222 if (mac_p == NULL)
223 return (0);
224
225 error = copyin(mac_p, &mac, sizeof(mac));
226 if (error)
227 return (error);
228
229 error = mac_check_structmac_consistent(&mac);
230 if (error)
231 return (error);
232
233 buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
234 error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
235 if (error) {
236 free(buffer, M_MACTEMP);
237 return (error);
238 }
239
240 label = mac_cred_label_alloc();
241 error = mac_cred_internalize_label(label, buffer);
242 free(buffer, M_MACTEMP);
243 if (error) {
244 mac_cred_label_free(label);
245 return (error);
246 }
247 imgp->execlabel = label;
248 return (0);
249}
250
251void
252mac_execve_exit(struct image_params *imgp)
253{
254 if (imgp->execlabel != NULL) {
255 mac_cred_label_free(imgp->execlabel);
256 imgp->execlabel = NULL;
257 }
258}
259
260/*
261 * When relabeling a process, call out to the policies for the maximum
262 * permission allowed for each object type we know about in its memory space,
263 * and revoke access (in the least surprising ways we know) when necessary.
264 * The process lock is not held here.
265 */
266void
267mac_cred_mmapped_drop_perms(struct thread *td, struct ucred *cred)
268{
269
270 /* XXX freeze all other threads */
271 mac_cred_mmapped_drop_perms_recurse(td, cred,
272 &td->td_proc->p_vmspace->vm_map);
273 /* XXX allow other threads to continue */
274}
275
276static __inline const char *
277prot2str(vm_prot_t prot)
278{
279
280 switch (prot & VM_PROT_ALL) {
281 case VM_PROT_READ:
282 return ("r--");
283 case VM_PROT_READ | VM_PROT_WRITE:
284 return ("rw-");
285 case VM_PROT_READ | VM_PROT_EXECUTE:
286 return ("r-x");
287 case VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE:
288 return ("rwx");
289 case VM_PROT_WRITE:
290 return ("-w-");
291 case VM_PROT_EXECUTE:
292 return ("--x");
293 case VM_PROT_WRITE | VM_PROT_EXECUTE:
294 return ("-wx");
295 default:
296 return ("---");
297 }
298}
299
300static void
301mac_cred_mmapped_drop_perms_recurse(struct thread *td, struct ucred *cred,
302 struct vm_map *map)
303{
304 struct vm_map_entry *vme;
305 int vfslocked, result;
306 vm_prot_t revokeperms;
307 vm_object_t backing_object, object;
308 vm_ooffset_t offset;
309 struct vnode *vp;
310 struct mount *mp;
311
312 if (!mac_mmap_revocation)
313 return;
314
315 vm_map_lock_read(map);
316 for (vme = map->header.next; vme != &map->header; vme = vme->next) {
317 if (vme->eflags & MAP_ENTRY_IS_SUB_MAP) {
318 mac_cred_mmapped_drop_perms_recurse(td, cred,
319 vme->object.sub_map);
320 continue;
321 }
322 /*
323 * Skip over entries that obviously are not shared.
324 */
325 if (vme->eflags & (MAP_ENTRY_COW | MAP_ENTRY_NOSYNC) ||
326 !vme->max_protection)
327 continue;
328 /*
329 * Drill down to the deepest backing object.
330 */
331 offset = vme->offset;
332 object = vme->object.vm_object;
333 if (object == NULL)
334 continue;
335 VM_OBJECT_LOCK(object);
336 while ((backing_object = object->backing_object) != NULL) {
337 VM_OBJECT_LOCK(backing_object);
338 offset += object->backing_object_offset;
339 VM_OBJECT_UNLOCK(object);
340 object = backing_object;
341 }
342 VM_OBJECT_UNLOCK(object);
343 /*
344 * At the moment, vm_maps and objects aren't considered by
345 * the MAC system, so only things with backing by a normal
346 * object (read: vnodes) are checked.
347 */
348 if (object->type != OBJT_VNODE)
349 continue;
350 vp = (struct vnode *)object->handle;
351 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
352 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
353 result = vme->max_protection;
354 mac_vnode_check_mmap_downgrade(cred, vp, &result);
355 VOP_UNLOCK(vp, 0, td);
356 /*
357 * Find out what maximum protection we may be allowing now
358 * but a policy needs to get removed.
359 */
360 revokeperms = vme->max_protection & ~result;
361 if (!revokeperms) {
362 VFS_UNLOCK_GIANT(vfslocked);
363 continue;
364 }
365 printf("pid %ld: revoking %s perms from %#lx:%ld "
366 "(max %s/cur %s)\n", (long)td->td_proc->p_pid,
367 prot2str(revokeperms), (u_long)vme->start,
368 (long)(vme->end - vme->start),
369 prot2str(vme->max_protection), prot2str(vme->protection));
370 vm_map_lock_upgrade(map);
371 /*
372 * This is the really simple case: if a map has more
373 * max_protection than is allowed, but it's not being
374 * actually used (that is, the current protection is still
375 * allowed), we can just wipe it out and do nothing more.
376 */
377 if ((vme->protection & revokeperms) == 0) {
378 vme->max_protection -= revokeperms;
379 } else {
380 if (revokeperms & VM_PROT_WRITE) {
381 /*
382 * In the more complicated case, flush out all
383 * pending changes to the object then turn it
384 * copy-on-write.
385 */
386 vm_object_reference(object);
387 (void) vn_start_write(vp, &mp, V_WAIT);
388 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
389 VM_OBJECT_LOCK(object);
390 vm_object_page_clean(object,
391 OFF_TO_IDX(offset),
392 OFF_TO_IDX(offset + vme->end - vme->start +
393 PAGE_MASK),
394 OBJPC_SYNC);
395 VM_OBJECT_UNLOCK(object);
396 VOP_UNLOCK(vp, 0, td);
397 vn_finished_write(mp);
398 vm_object_deallocate(object);
399 /*
400 * Why bother if there's no read permissions
401 * anymore? For the rest, we need to leave
402 * the write permissions on for COW, or
403 * remove them entirely if configured to.
404 */
405 if (!mac_mmap_revocation_via_cow) {
406 vme->max_protection &= ~VM_PROT_WRITE;
407 vme->protection &= ~VM_PROT_WRITE;
408 } if ((revokeperms & VM_PROT_READ) == 0)
409 vme->eflags |= MAP_ENTRY_COW |
410 MAP_ENTRY_NEEDS_COPY;
411 }
412 if (revokeperms & VM_PROT_EXECUTE) {
413 vme->max_protection &= ~VM_PROT_EXECUTE;
414 vme->protection &= ~VM_PROT_EXECUTE;
415 }
416 if (revokeperms & VM_PROT_READ) {
417 vme->max_protection = 0;
418 vme->protection = 0;
419 }
420 pmap_protect(map->pmap, vme->start, vme->end,
421 vme->protection & ~revokeperms);
422 vm_map_simplify_entry(map, vme);
423 }
424 vm_map_lock_downgrade(map);
425 VFS_UNLOCK_GIANT(vfslocked);
426 }
427 vm_map_unlock_read(map);
428}
429
430/*
431 * When the subject's label changes, it may require revocation of privilege
432 * to mapped objects. This can't be done on-the-fly later with a unified
433 * buffer cache.
434 */
435void
436mac_cred_relabel(struct ucred *cred, struct label *newlabel)
437{
438
439 MAC_PERFORM(cred_relabel, cred, newlabel);
440}
441
442int
443mac_cred_check_relabel(struct ucred *cred, struct label *newlabel)
444{
445 int error;
446
447 MAC_CHECK(cred_check_relabel, cred, newlabel);
448
449 return (error);
450}
451
452int
453mac_cred_check_visible(struct ucred *cr1, struct ucred *cr2)
454{
455 int error;
456
457 MAC_CHECK(cred_check_visible, cr1, cr2);
458
459 return (error);
460}
461
462int
463mac_proc_check_debug(struct ucred *cred, struct proc *p)
464{
465 int error;
466
467 PROC_LOCK_ASSERT(p, MA_OWNED);
468
469 MAC_CHECK(proc_check_debug, cred, p);
470
471 return (error);
472}
473
474int
475mac_proc_check_sched(struct ucred *cred, struct proc *p)
476{
477 int error;
478
479 PROC_LOCK_ASSERT(p, MA_OWNED);
480
481 MAC_CHECK(proc_check_sched, cred, p);
482
483 return (error);
484}
485
486int
487mac_proc_check_signal(struct ucred *cred, struct proc *p, int signum)
488{
489 int error;
490
491 PROC_LOCK_ASSERT(p, MA_OWNED);
492
493 MAC_CHECK(proc_check_signal, cred, p, signum);
494
495 return (error);
496}
497
498int
499mac_proc_check_setuid(struct proc *p, struct ucred *cred, uid_t uid)
500{
501 int error;
502
503 PROC_LOCK_ASSERT(p, MA_OWNED);
504
505 MAC_CHECK(proc_check_setuid, cred, uid);
506 return (error);
507}
508
509int
510mac_proc_check_seteuid(struct proc *p, struct ucred *cred, uid_t euid)
511{
512 int error;
513
514 PROC_LOCK_ASSERT(p, MA_OWNED);
515
516 MAC_CHECK(proc_check_seteuid, cred, euid);
517 return (error);
518}
519
520int
521mac_proc_check_setgid(struct proc *p, struct ucred *cred, gid_t gid)
522{
523 int error;
524
525 PROC_LOCK_ASSERT(p, MA_OWNED);
526
527 MAC_CHECK(proc_check_setgid, cred, gid);
528
529 return (error);
530}
531
532int
533mac_proc_check_setegid(struct proc *p, struct ucred *cred, gid_t egid)
534{
535 int error;
536
537 PROC_LOCK_ASSERT(p, MA_OWNED);
538
539 MAC_CHECK(proc_check_setegid, cred, egid);
540
541 return (error);
542}
543
544int
545mac_proc_check_setgroups(struct proc *p, struct ucred *cred, int ngroups,
546 gid_t *gidset)
547{
548 int error;
549
550 PROC_LOCK_ASSERT(p, MA_OWNED);
551
552 MAC_CHECK(proc_check_setgroups, cred, ngroups, gidset);
553 return (error);
554}
555
556int
557mac_proc_check_setreuid(struct proc *p, struct ucred *cred, uid_t ruid,
558 uid_t euid)
559{
560 int error;
561
562 PROC_LOCK_ASSERT(p, MA_OWNED);
563
564 MAC_CHECK(proc_check_setreuid, cred, ruid, euid);
565
566 return (error);
567}
568
569int
570mac_proc_check_setregid(struct proc *proc, struct ucred *cred, gid_t rgid,
571 gid_t egid)
572{
573 int error;
574
575 PROC_LOCK_ASSERT(proc, MA_OWNED);
576
577 MAC_CHECK(proc_check_setregid, cred, rgid, egid);
578
579 return (error);
580}
581
582int
583mac_proc_check_setresuid(struct proc *p, struct ucred *cred, uid_t ruid,
584 uid_t euid, uid_t suid)
585{
586 int error;
587
588 PROC_LOCK_ASSERT(p, MA_OWNED);
589
590 MAC_CHECK(proc_check_setresuid, cred, ruid, euid, suid);
591 return (error);
592}
593
594int
595mac_proc_check_setresgid(struct proc *p, struct ucred *cred, gid_t rgid,
596 gid_t egid, gid_t sgid)
597{
598 int error;
599
600 PROC_LOCK_ASSERT(p, MA_OWNED);
601
602 MAC_CHECK(proc_check_setresgid, cred, rgid, egid, sgid);
603
604 return (error);
605}
606
607int
608mac_proc_check_wait(struct ucred *cred, struct proc *p)
609{
610 int error;
611
612 PROC_LOCK_ASSERT(p, MA_OWNED);
613
614 MAC_CHECK(proc_check_wait, cred, p);
615
616 return (error);
617}
2 * Copyright (c) 1999-2002 Robert N. M. Watson
3 * Copyright (c) 2001 Ilmar S. Habibulin
4 * Copyright (c) 2001-2003 Networks Associates Technology, Inc.
5 * Copyright (c) 2005 Samy Al Bahra
6 * Copyright (c) 2006 SPARTA, Inc.
7 * All rights reserved.
8 *
9 * This software was developed by Robert Watson and Ilmar Habibulin for the
10 * TrustedBSD Project.
11 *
12 * This software was developed for the FreeBSD Project in part by Network
13 * Associates Laboratories, the Security Research Division of Network
14 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
15 * as part of the DARPA CHATS research program.
16 *
17 * This software was enhanced by SPARTA ISSO under SPAWAR contract
18 * N66001-04-C-6019 ("SEFOS").
19 *
20 * Redistribution and use in source and binary forms, with or without
21 * modification, are permitted provided that the following conditions
22 * are met:
23 * 1. Redistributions of source code must retain the above copyright
24 * notice, this list of conditions and the following disclaimer.
25 * 2. Redistributions in binary form must reproduce the above copyright
26 * notice, this list of conditions and the following disclaimer in the
27 * documentation and/or other materials provided with the distribution.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * SUCH DAMAGE.
40 */
41
42#include <sys/cdefs.h>
43__FBSDID("$FreeBSD: head/sys/security/mac/mac_process.c 172930 2007-10-24 19:04:04Z rwatson $");
44
45#include "opt_mac.h"
46
47#include <sys/param.h>
48#include <sys/condvar.h>
49#include <sys/imgact.h>
50#include <sys/kernel.h>
51#include <sys/lock.h>
52#include <sys/malloc.h>
53#include <sys/mutex.h>
54#include <sys/mac.h>
55#include <sys/proc.h>
56#include <sys/sbuf.h>
57#include <sys/systm.h>
58#include <sys/vnode.h>
59#include <sys/mount.h>
60#include <sys/file.h>
61#include <sys/namei.h>
62#include <sys/sysctl.h>
63
64#include <vm/vm.h>
65#include <vm/pmap.h>
66#include <vm/vm_map.h>
67#include <vm/vm_object.h>
68
69#include <security/mac/mac_framework.h>
70#include <security/mac/mac_internal.h>
71#include <security/mac/mac_policy.h>
72
73static int mac_mmap_revocation = 1;
74SYSCTL_INT(_security_mac, OID_AUTO, mmap_revocation, CTLFLAG_RW,
75 &mac_mmap_revocation, 0, "Revoke mmap access to files on subject "
76 "relabel");
77
78static int mac_mmap_revocation_via_cow = 0;
79SYSCTL_INT(_security_mac, OID_AUTO, mmap_revocation_via_cow, CTLFLAG_RW,
80 &mac_mmap_revocation_via_cow, 0, "Revoke mmap access to files via "
81 "copy-on-write semantics, or by removing all write access");
82
83static void mac_cred_mmapped_drop_perms_recurse(struct thread *td,
84 struct ucred *cred, struct vm_map *map);
85
86struct label *
87mac_cred_label_alloc(void)
88{
89 struct label *label;
90
91 label = mac_labelzone_alloc(M_WAITOK);
92 MAC_PERFORM(cred_init_label, label);
93 return (label);
94}
95
96void
97mac_cred_init(struct ucred *cred)
98{
99
100 cred->cr_label = mac_cred_label_alloc();
101}
102
103static struct label *
104mac_proc_label_alloc(void)
105{
106 struct label *label;
107
108 label = mac_labelzone_alloc(M_WAITOK);
109 MAC_PERFORM(proc_init_label, label);
110 return (label);
111}
112
113void
114mac_proc_init(struct proc *p)
115{
116
117 p->p_label = mac_proc_label_alloc();
118}
119
120void
121mac_cred_label_free(struct label *label)
122{
123
124 MAC_PERFORM(cred_destroy_label, label);
125 mac_labelzone_free(label);
126}
127
128void
129mac_cred_destroy(struct ucred *cred)
130{
131
132 mac_cred_label_free(cred->cr_label);
133 cred->cr_label = NULL;
134}
135
136static void
137mac_proc_label_free(struct label *label)
138{
139
140 MAC_PERFORM(proc_destroy_label, label);
141 mac_labelzone_free(label);
142}
143
144void
145mac_proc_destroy(struct proc *p)
146{
147
148 mac_proc_label_free(p->p_label);
149 p->p_label = NULL;
150}
151
152int
153mac_cred_externalize_label(struct label *label, char *elements,
154 char *outbuf, size_t outbuflen)
155{
156 int error;
157
158 MAC_EXTERNALIZE(cred, label, elements, outbuf, outbuflen);
159
160 return (error);
161}
162
163int
164mac_cred_internalize_label(struct label *label, char *string)
165{
166 int error;
167
168 MAC_INTERNALIZE(cred, label, string);
169
170 return (error);
171}
172
173/*
174 * Initialize MAC label for the first kernel process, from which other kernel
175 * processes and threads are spawned.
176 */
177void
178mac_proc_create_swapper(struct ucred *cred)
179{
180
181 MAC_PERFORM(proc_create_swapper, cred);
182}
183
184/*
185 * Initialize MAC label for the first userland process, from which other
186 * userland processes and threads are spawned.
187 */
188void
189mac_proc_create_init(struct ucred *cred)
190{
191
192 MAC_PERFORM(proc_create_init, cred);
193}
194
195void
196mac_thread_userret(struct thread *td)
197{
198
199 MAC_PERFORM(thread_userret, td);
200}
201
202/*
203 * When a new process is created, its label must be initialized. Generally,
204 * this involves inheritence from the parent process, modulo possible deltas.
205 * This function allows that processing to take place.
206 */
207void
208mac_cred_copy(struct ucred *src, struct ucred *dest)
209{
210
211 MAC_PERFORM(cred_copy_label, src->cr_label, dest->cr_label);
212}
213
214int
215mac_execve_enter(struct image_params *imgp, struct mac *mac_p)
216{
217 struct label *label;
218 struct mac mac;
219 char *buffer;
220 int error;
221
222 if (mac_p == NULL)
223 return (0);
224
225 error = copyin(mac_p, &mac, sizeof(mac));
226 if (error)
227 return (error);
228
229 error = mac_check_structmac_consistent(&mac);
230 if (error)
231 return (error);
232
233 buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
234 error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
235 if (error) {
236 free(buffer, M_MACTEMP);
237 return (error);
238 }
239
240 label = mac_cred_label_alloc();
241 error = mac_cred_internalize_label(label, buffer);
242 free(buffer, M_MACTEMP);
243 if (error) {
244 mac_cred_label_free(label);
245 return (error);
246 }
247 imgp->execlabel = label;
248 return (0);
249}
250
251void
252mac_execve_exit(struct image_params *imgp)
253{
254 if (imgp->execlabel != NULL) {
255 mac_cred_label_free(imgp->execlabel);
256 imgp->execlabel = NULL;
257 }
258}
259
260/*
261 * When relabeling a process, call out to the policies for the maximum
262 * permission allowed for each object type we know about in its memory space,
263 * and revoke access (in the least surprising ways we know) when necessary.
264 * The process lock is not held here.
265 */
266void
267mac_cred_mmapped_drop_perms(struct thread *td, struct ucred *cred)
268{
269
270 /* XXX freeze all other threads */
271 mac_cred_mmapped_drop_perms_recurse(td, cred,
272 &td->td_proc->p_vmspace->vm_map);
273 /* XXX allow other threads to continue */
274}
275
276static __inline const char *
277prot2str(vm_prot_t prot)
278{
279
280 switch (prot & VM_PROT_ALL) {
281 case VM_PROT_READ:
282 return ("r--");
283 case VM_PROT_READ | VM_PROT_WRITE:
284 return ("rw-");
285 case VM_PROT_READ | VM_PROT_EXECUTE:
286 return ("r-x");
287 case VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE:
288 return ("rwx");
289 case VM_PROT_WRITE:
290 return ("-w-");
291 case VM_PROT_EXECUTE:
292 return ("--x");
293 case VM_PROT_WRITE | VM_PROT_EXECUTE:
294 return ("-wx");
295 default:
296 return ("---");
297 }
298}
299
300static void
301mac_cred_mmapped_drop_perms_recurse(struct thread *td, struct ucred *cred,
302 struct vm_map *map)
303{
304 struct vm_map_entry *vme;
305 int vfslocked, result;
306 vm_prot_t revokeperms;
307 vm_object_t backing_object, object;
308 vm_ooffset_t offset;
309 struct vnode *vp;
310 struct mount *mp;
311
312 if (!mac_mmap_revocation)
313 return;
314
315 vm_map_lock_read(map);
316 for (vme = map->header.next; vme != &map->header; vme = vme->next) {
317 if (vme->eflags & MAP_ENTRY_IS_SUB_MAP) {
318 mac_cred_mmapped_drop_perms_recurse(td, cred,
319 vme->object.sub_map);
320 continue;
321 }
322 /*
323 * Skip over entries that obviously are not shared.
324 */
325 if (vme->eflags & (MAP_ENTRY_COW | MAP_ENTRY_NOSYNC) ||
326 !vme->max_protection)
327 continue;
328 /*
329 * Drill down to the deepest backing object.
330 */
331 offset = vme->offset;
332 object = vme->object.vm_object;
333 if (object == NULL)
334 continue;
335 VM_OBJECT_LOCK(object);
336 while ((backing_object = object->backing_object) != NULL) {
337 VM_OBJECT_LOCK(backing_object);
338 offset += object->backing_object_offset;
339 VM_OBJECT_UNLOCK(object);
340 object = backing_object;
341 }
342 VM_OBJECT_UNLOCK(object);
343 /*
344 * At the moment, vm_maps and objects aren't considered by
345 * the MAC system, so only things with backing by a normal
346 * object (read: vnodes) are checked.
347 */
348 if (object->type != OBJT_VNODE)
349 continue;
350 vp = (struct vnode *)object->handle;
351 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
352 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
353 result = vme->max_protection;
354 mac_vnode_check_mmap_downgrade(cred, vp, &result);
355 VOP_UNLOCK(vp, 0, td);
356 /*
357 * Find out what maximum protection we may be allowing now
358 * but a policy needs to get removed.
359 */
360 revokeperms = vme->max_protection & ~result;
361 if (!revokeperms) {
362 VFS_UNLOCK_GIANT(vfslocked);
363 continue;
364 }
365 printf("pid %ld: revoking %s perms from %#lx:%ld "
366 "(max %s/cur %s)\n", (long)td->td_proc->p_pid,
367 prot2str(revokeperms), (u_long)vme->start,
368 (long)(vme->end - vme->start),
369 prot2str(vme->max_protection), prot2str(vme->protection));
370 vm_map_lock_upgrade(map);
371 /*
372 * This is the really simple case: if a map has more
373 * max_protection than is allowed, but it's not being
374 * actually used (that is, the current protection is still
375 * allowed), we can just wipe it out and do nothing more.
376 */
377 if ((vme->protection & revokeperms) == 0) {
378 vme->max_protection -= revokeperms;
379 } else {
380 if (revokeperms & VM_PROT_WRITE) {
381 /*
382 * In the more complicated case, flush out all
383 * pending changes to the object then turn it
384 * copy-on-write.
385 */
386 vm_object_reference(object);
387 (void) vn_start_write(vp, &mp, V_WAIT);
388 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
389 VM_OBJECT_LOCK(object);
390 vm_object_page_clean(object,
391 OFF_TO_IDX(offset),
392 OFF_TO_IDX(offset + vme->end - vme->start +
393 PAGE_MASK),
394 OBJPC_SYNC);
395 VM_OBJECT_UNLOCK(object);
396 VOP_UNLOCK(vp, 0, td);
397 vn_finished_write(mp);
398 vm_object_deallocate(object);
399 /*
400 * Why bother if there's no read permissions
401 * anymore? For the rest, we need to leave
402 * the write permissions on for COW, or
403 * remove them entirely if configured to.
404 */
405 if (!mac_mmap_revocation_via_cow) {
406 vme->max_protection &= ~VM_PROT_WRITE;
407 vme->protection &= ~VM_PROT_WRITE;
408 } if ((revokeperms & VM_PROT_READ) == 0)
409 vme->eflags |= MAP_ENTRY_COW |
410 MAP_ENTRY_NEEDS_COPY;
411 }
412 if (revokeperms & VM_PROT_EXECUTE) {
413 vme->max_protection &= ~VM_PROT_EXECUTE;
414 vme->protection &= ~VM_PROT_EXECUTE;
415 }
416 if (revokeperms & VM_PROT_READ) {
417 vme->max_protection = 0;
418 vme->protection = 0;
419 }
420 pmap_protect(map->pmap, vme->start, vme->end,
421 vme->protection & ~revokeperms);
422 vm_map_simplify_entry(map, vme);
423 }
424 vm_map_lock_downgrade(map);
425 VFS_UNLOCK_GIANT(vfslocked);
426 }
427 vm_map_unlock_read(map);
428}
429
430/*
431 * When the subject's label changes, it may require revocation of privilege
432 * to mapped objects. This can't be done on-the-fly later with a unified
433 * buffer cache.
434 */
435void
436mac_cred_relabel(struct ucred *cred, struct label *newlabel)
437{
438
439 MAC_PERFORM(cred_relabel, cred, newlabel);
440}
441
442int
443mac_cred_check_relabel(struct ucred *cred, struct label *newlabel)
444{
445 int error;
446
447 MAC_CHECK(cred_check_relabel, cred, newlabel);
448
449 return (error);
450}
451
452int
453mac_cred_check_visible(struct ucred *cr1, struct ucred *cr2)
454{
455 int error;
456
457 MAC_CHECK(cred_check_visible, cr1, cr2);
458
459 return (error);
460}
461
462int
463mac_proc_check_debug(struct ucred *cred, struct proc *p)
464{
465 int error;
466
467 PROC_LOCK_ASSERT(p, MA_OWNED);
468
469 MAC_CHECK(proc_check_debug, cred, p);
470
471 return (error);
472}
473
474int
475mac_proc_check_sched(struct ucred *cred, struct proc *p)
476{
477 int error;
478
479 PROC_LOCK_ASSERT(p, MA_OWNED);
480
481 MAC_CHECK(proc_check_sched, cred, p);
482
483 return (error);
484}
485
486int
487mac_proc_check_signal(struct ucred *cred, struct proc *p, int signum)
488{
489 int error;
490
491 PROC_LOCK_ASSERT(p, MA_OWNED);
492
493 MAC_CHECK(proc_check_signal, cred, p, signum);
494
495 return (error);
496}
497
498int
499mac_proc_check_setuid(struct proc *p, struct ucred *cred, uid_t uid)
500{
501 int error;
502
503 PROC_LOCK_ASSERT(p, MA_OWNED);
504
505 MAC_CHECK(proc_check_setuid, cred, uid);
506 return (error);
507}
508
509int
510mac_proc_check_seteuid(struct proc *p, struct ucred *cred, uid_t euid)
511{
512 int error;
513
514 PROC_LOCK_ASSERT(p, MA_OWNED);
515
516 MAC_CHECK(proc_check_seteuid, cred, euid);
517 return (error);
518}
519
520int
521mac_proc_check_setgid(struct proc *p, struct ucred *cred, gid_t gid)
522{
523 int error;
524
525 PROC_LOCK_ASSERT(p, MA_OWNED);
526
527 MAC_CHECK(proc_check_setgid, cred, gid);
528
529 return (error);
530}
531
532int
533mac_proc_check_setegid(struct proc *p, struct ucred *cred, gid_t egid)
534{
535 int error;
536
537 PROC_LOCK_ASSERT(p, MA_OWNED);
538
539 MAC_CHECK(proc_check_setegid, cred, egid);
540
541 return (error);
542}
543
544int
545mac_proc_check_setgroups(struct proc *p, struct ucred *cred, int ngroups,
546 gid_t *gidset)
547{
548 int error;
549
550 PROC_LOCK_ASSERT(p, MA_OWNED);
551
552 MAC_CHECK(proc_check_setgroups, cred, ngroups, gidset);
553 return (error);
554}
555
556int
557mac_proc_check_setreuid(struct proc *p, struct ucred *cred, uid_t ruid,
558 uid_t euid)
559{
560 int error;
561
562 PROC_LOCK_ASSERT(p, MA_OWNED);
563
564 MAC_CHECK(proc_check_setreuid, cred, ruid, euid);
565
566 return (error);
567}
568
569int
570mac_proc_check_setregid(struct proc *proc, struct ucred *cred, gid_t rgid,
571 gid_t egid)
572{
573 int error;
574
575 PROC_LOCK_ASSERT(proc, MA_OWNED);
576
577 MAC_CHECK(proc_check_setregid, cred, rgid, egid);
578
579 return (error);
580}
581
582int
583mac_proc_check_setresuid(struct proc *p, struct ucred *cred, uid_t ruid,
584 uid_t euid, uid_t suid)
585{
586 int error;
587
588 PROC_LOCK_ASSERT(p, MA_OWNED);
589
590 MAC_CHECK(proc_check_setresuid, cred, ruid, euid, suid);
591 return (error);
592}
593
594int
595mac_proc_check_setresgid(struct proc *p, struct ucred *cred, gid_t rgid,
596 gid_t egid, gid_t sgid)
597{
598 int error;
599
600 PROC_LOCK_ASSERT(p, MA_OWNED);
601
602 MAC_CHECK(proc_check_setresgid, cred, rgid, egid, sgid);
603
604 return (error);
605}
606
607int
608mac_proc_check_wait(struct ucred *cred, struct proc *p)
609{
610 int error;
611
612 PROC_LOCK_ASSERT(p, MA_OWNED);
613
614 MAC_CHECK(proc_check_wait, cred, p);
615
616 return (error);
617}