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 * All rights reserved.
7 *
8 * This software was developed by Robert Watson and Ilmar Habibulin for the
9 * TrustedBSD Project.
10 *
11 * This software was developed for the FreeBSD Project in part by Network
12 * Associates Laboratories, the Security Research Division of Network
13 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
14 * as part of the DARPA CHATS research program.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 * 1. Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: head/sys/security/mac/mac_process.c 168955 2007-04-22 19:55:56Z rwatson $");
40
41#include "opt_mac.h"
42
43#include <sys/param.h>
44#include <sys/condvar.h>
45#include <sys/imgact.h>
46#include <sys/kernel.h>
47#include <sys/lock.h>
48#include <sys/malloc.h>
49#include <sys/mutex.h>
50#include <sys/mac.h>
51#include <sys/proc.h>
52#include <sys/sbuf.h>
53#include <sys/systm.h>
54#include <sys/vnode.h>
55#include <sys/mount.h>
56#include <sys/file.h>
57#include <sys/namei.h>
58#include <sys/sysctl.h>
59
60#include <vm/vm.h>
61#include <vm/pmap.h>
62#include <vm/vm_map.h>
63#include <vm/vm_object.h>
64
65#include <security/mac/mac_framework.h>
66#include <security/mac/mac_internal.h>
67#include <security/mac/mac_policy.h>
68
69static int mac_mmap_revocation = 1;
70SYSCTL_INT(_security_mac, OID_AUTO, mmap_revocation, CTLFLAG_RW,
71 &mac_mmap_revocation, 0, "Revoke mmap access to files on subject "
72 "relabel");
73
74static int mac_mmap_revocation_via_cow = 0;
75SYSCTL_INT(_security_mac, OID_AUTO, mmap_revocation_via_cow, CTLFLAG_RW,
76 &mac_mmap_revocation_via_cow, 0, "Revoke mmap access to files via "
77 "copy-on-write semantics, or by removing all write access");
78
79static void mac_cred_mmapped_drop_perms_recurse(struct thread *td,
80 struct ucred *cred, struct vm_map *map);
81
82struct label *
83mac_cred_label_alloc(void)
84{
85 struct label *label;
86
87 label = mac_labelzone_alloc(M_WAITOK);
88 MAC_PERFORM(init_cred_label, label);
89 return (label);
90}
91
92void
93mac_init_cred(struct ucred *cred)
94{
95
96 cred->cr_label = mac_cred_label_alloc();
97}
98
99static struct label *
100mac_proc_label_alloc(void)
101{
102 struct label *label;
103
104 label = mac_labelzone_alloc(M_WAITOK);
105 MAC_PERFORM(init_proc_label, label);
106 return (label);
107}
108
109void
110mac_init_proc(struct proc *p)
111{
112
113 p->p_label = mac_proc_label_alloc();
114}
115
116void
117mac_cred_label_free(struct label *label)
118{
119
120 MAC_PERFORM(destroy_cred_label, label);
121 mac_labelzone_free(label);
122}
123
124void
125mac_destroy_cred(struct ucred *cred)
126{
127
128 mac_cred_label_free(cred->cr_label);
129 cred->cr_label = NULL;
130}
131
132static void
133mac_proc_label_free(struct label *label)
134{
135
136 MAC_PERFORM(destroy_proc_label, label);
137 mac_labelzone_free(label);
138}
139
140void
141mac_destroy_proc(struct proc *p)
142{
143
144 mac_proc_label_free(p->p_label);
145 p->p_label = NULL;
146}
147
148int
149mac_externalize_cred_label(struct label *label, char *elements,
150 char *outbuf, size_t outbuflen)
151{
152 int error;
153
154 MAC_EXTERNALIZE(cred, label, elements, outbuf, outbuflen);
155
156 return (error);
157}
158
159int
160mac_internalize_cred_label(struct label *label, char *string)
161{
162 int error;
163
164 MAC_INTERNALIZE(cred, label, string);
165
166 return (error);
167}
168
169/*
170 * Initialize MAC label for the first kernel process, from which other kernel
171 * processes and threads are spawned.
172 */
173void
174mac_create_proc0(struct ucred *cred)
175{
176
177 MAC_PERFORM(create_proc0, cred);
178}
179
180/*
181 * Initialize MAC label for the first userland process, from which other
182 * userland processes and threads are spawned.
183 */
184void
185mac_create_proc1(struct ucred *cred)
186{
187
188 MAC_PERFORM(create_proc1, cred);
189}
190
191void
192mac_thread_userret(struct thread *td)
193{
194
195 MAC_PERFORM(thread_userret, td);
196}
197
198/*
199 * When a new process is created, its label must be initialized. Generally,
200 * this involves inheritence from the parent process, modulo possible deltas.
201 * This function allows that processing to take place.
202 */
203void
204mac_copy_cred(struct ucred *src, struct ucred *dest)
205{
206
207 MAC_PERFORM(copy_cred_label, src->cr_label, dest->cr_label);
208}
209
210int
211mac_execve_enter(struct image_params *imgp, struct mac *mac_p)
212{
213 struct label *label;
214 struct mac mac;
215 char *buffer;
216 int error;
217
218 if (mac_p == NULL)
219 return (0);
220
221 error = copyin(mac_p, &mac, sizeof(mac));
222 if (error)
223 return (error);
224
225 error = mac_check_structmac_consistent(&mac);
226 if (error)
227 return (error);
228
229 buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
230 error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
231 if (error) {
232 free(buffer, M_MACTEMP);
233 return (error);
234 }
235
236 label = mac_cred_label_alloc();
237 error = mac_internalize_cred_label(label, buffer);
238 free(buffer, M_MACTEMP);
239 if (error) {
240 mac_cred_label_free(label);
241 return (error);
242 }
243 imgp->execlabel = label;
244 return (0);
245}
246
247void
248mac_execve_exit(struct image_params *imgp)
249{
250 if (imgp->execlabel != NULL) {
251 mac_cred_label_free(imgp->execlabel);
252 imgp->execlabel = NULL;
253 }
254}
255
256/*
257 * When relabeling a process, call out to the policies for the maximum
258 * permission allowed for each object type we know about in its memory space,
259 * and revoke access (in the least surprising ways we know) when necessary.
260 * The process lock is not held here.
261 */
262void
263mac_cred_mmapped_drop_perms(struct thread *td, struct ucred *cred)
264{
265
266 /* XXX freeze all other threads */
267 mac_cred_mmapped_drop_perms_recurse(td, cred,
268 &td->td_proc->p_vmspace->vm_map);
269 /* XXX allow other threads to continue */
270}
271
272static __inline const char *
273prot2str(vm_prot_t prot)
274{
275
276 switch (prot & VM_PROT_ALL) {
277 case VM_PROT_READ:
278 return ("r--");
279 case VM_PROT_READ | VM_PROT_WRITE:
280 return ("rw-");
281 case VM_PROT_READ | VM_PROT_EXECUTE:
282 return ("r-x");
283 case VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE:
284 return ("rwx");
285 case VM_PROT_WRITE:
286 return ("-w-");
287 case VM_PROT_EXECUTE:
288 return ("--x");
289 case VM_PROT_WRITE | VM_PROT_EXECUTE:
290 return ("-wx");
291 default:
292 return ("---");
293 }
294}
295
296static void
297mac_cred_mmapped_drop_perms_recurse(struct thread *td, struct ucred *cred,
298 struct vm_map *map)
299{
300 struct vm_map_entry *vme;
301 int vfslocked, result;
302 vm_prot_t revokeperms;
303 vm_object_t backing_object, object;
304 vm_ooffset_t offset;
305 struct vnode *vp;
306 struct mount *mp;
307
308 if (!mac_mmap_revocation)
309 return;
310
311 vm_map_lock_read(map);
312 for (vme = map->header.next; vme != &map->header; vme = vme->next) {
313 if (vme->eflags & MAP_ENTRY_IS_SUB_MAP) {
314 mac_cred_mmapped_drop_perms_recurse(td, cred,
315 vme->object.sub_map);
316 continue;
317 }
318 /*
319 * Skip over entries that obviously are not shared.
320 */
321 if (vme->eflags & (MAP_ENTRY_COW | MAP_ENTRY_NOSYNC) ||
322 !vme->max_protection)
323 continue;
324 /*
325 * Drill down to the deepest backing object.
326 */
327 offset = vme->offset;
328 object = vme->object.vm_object;
329 if (object == NULL)
330 continue;
331 VM_OBJECT_LOCK(object);
332 while ((backing_object = object->backing_object) != NULL) {
333 VM_OBJECT_LOCK(backing_object);
334 offset += object->backing_object_offset;
335 VM_OBJECT_UNLOCK(object);
336 object = backing_object;
337 }
338 VM_OBJECT_UNLOCK(object);
339 /*
340 * At the moment, vm_maps and objects aren't considered by
341 * the MAC system, so only things with backing by a normal
342 * object (read: vnodes) are checked.
343 */
344 if (object->type != OBJT_VNODE)
345 continue;
346 vp = (struct vnode *)object->handle;
347 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
348 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
349 result = vme->max_protection;
350 mac_check_vnode_mmap_downgrade(cred, vp, &result);
351 VOP_UNLOCK(vp, 0, td);
352 /*
353 * Find out what maximum protection we may be allowing now
354 * but a policy needs to get removed.
355 */
356 revokeperms = vme->max_protection & ~result;
357 if (!revokeperms) {
358 VFS_UNLOCK_GIANT(vfslocked);
359 continue;
360 }
361 printf("pid %ld: revoking %s perms from %#lx:%ld "
362 "(max %s/cur %s)\n", (long)td->td_proc->p_pid,
363 prot2str(revokeperms), (u_long)vme->start,
364 (long)(vme->end - vme->start),
365 prot2str(vme->max_protection), prot2str(vme->protection));
366 vm_map_lock_upgrade(map);
367 /*
368 * This is the really simple case: if a map has more
369 * max_protection than is allowed, but it's not being
370 * actually used (that is, the current protection is still
371 * allowed), we can just wipe it out and do nothing more.
372 */
373 if ((vme->protection & revokeperms) == 0) {
374 vme->max_protection -= revokeperms;
375 } else {
376 if (revokeperms & VM_PROT_WRITE) {
377 /*
378 * In the more complicated case, flush out all
379 * pending changes to the object then turn it
380 * copy-on-write.
381 */
382 vm_object_reference(object);
383 (void) vn_start_write(vp, &mp, V_WAIT);
384 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
385 VM_OBJECT_LOCK(object);
386 vm_object_page_clean(object,
387 OFF_TO_IDX(offset),
388 OFF_TO_IDX(offset + vme->end - vme->start +
389 PAGE_MASK),
390 OBJPC_SYNC);
391 VM_OBJECT_UNLOCK(object);
392 VOP_UNLOCK(vp, 0, td);
393 vn_finished_write(mp);
394 vm_object_deallocate(object);
395 /*
396 * Why bother if there's no read permissions
397 * anymore? For the rest, we need to leave
398 * the write permissions on for COW, or
399 * remove them entirely if configured to.
400 */
401 if (!mac_mmap_revocation_via_cow) {
402 vme->max_protection &= ~VM_PROT_WRITE;
403 vme->protection &= ~VM_PROT_WRITE;
404 } if ((revokeperms & VM_PROT_READ) == 0)
405 vme->eflags |= MAP_ENTRY_COW |
406 MAP_ENTRY_NEEDS_COPY;
407 }
408 if (revokeperms & VM_PROT_EXECUTE) {
409 vme->max_protection &= ~VM_PROT_EXECUTE;
410 vme->protection &= ~VM_PROT_EXECUTE;
411 }
412 if (revokeperms & VM_PROT_READ) {
413 vme->max_protection = 0;
414 vme->protection = 0;
415 }
416 pmap_protect(map->pmap, vme->start, vme->end,
417 vme->protection & ~revokeperms);
418 vm_map_simplify_entry(map, vme);
419 }
420 vm_map_lock_downgrade(map);
421 VFS_UNLOCK_GIANT(vfslocked);
422 }
423 vm_map_unlock_read(map);
424}
425
426/*
427 * When the subject's label changes, it may require revocation of privilege
428 * to mapped objects. This can't be done on-the-fly later with a unified
429 * buffer cache.
430 */
431void
432mac_relabel_cred(struct ucred *cred, struct label *newlabel)
433{
434
435 MAC_PERFORM(relabel_cred, cred, newlabel);
436}
437
438int
439mac_check_cred_relabel(struct ucred *cred, struct label *newlabel)
440{
441 int error;
442
443 MAC_CHECK(check_cred_relabel, cred, newlabel);
444
445 return (error);
446}
447
448int
449mac_check_cred_visible(struct ucred *cr1, struct ucred *cr2)
450{
451 int error;
452
453 MAC_CHECK(check_cred_visible, cr1, cr2);
454
455 return (error);
456}
457
458int
459mac_check_proc_debug(struct ucred *cred, struct proc *p)
460{
461 int error;
462
463 PROC_LOCK_ASSERT(p, MA_OWNED);
464
465 MAC_CHECK(check_proc_debug, cred, p);
466
467 return (error);
468}
469
470int
471mac_check_proc_sched(struct ucred *cred, struct proc *p)
472{
473 int error;
474
475 PROC_LOCK_ASSERT(p, MA_OWNED);
476
477 MAC_CHECK(check_proc_sched, cred, p);
478
479 return (error);
480}
481
482int
483mac_check_proc_signal(struct ucred *cred, struct proc *p, int signum)
484{
485 int error;
486
487 PROC_LOCK_ASSERT(p, MA_OWNED);
488
489 MAC_CHECK(check_proc_signal, cred, p, signum);
490
491 return (error);
492}
493
494int
495mac_check_proc_setuid(struct proc *p, struct ucred *cred, uid_t uid)
496{
497 int error;
498
499 PROC_LOCK_ASSERT(p, MA_OWNED);
500
501 MAC_CHECK(check_proc_setuid, cred, uid);
502 return (error);
503}
504
505int
506mac_check_proc_seteuid(struct proc *p, struct ucred *cred, uid_t euid)
507{
508 int error;
509
510 PROC_LOCK_ASSERT(p, MA_OWNED);
511
512 MAC_CHECK(check_proc_seteuid, cred, euid);
513 return (error);
514}
515
516int
517mac_check_proc_setgid(struct proc *p, struct ucred *cred, gid_t gid)
518{
519 int error;
520
521 PROC_LOCK_ASSERT(p, MA_OWNED);
522
523 MAC_CHECK(check_proc_setgid, cred, gid);
524
525 return (error);
526}
527
528int
529mac_check_proc_setegid(struct proc *p, struct ucred *cred, gid_t egid)
530{
531 int error;
532
533 PROC_LOCK_ASSERT(p, MA_OWNED);
534
535 MAC_CHECK(check_proc_setegid, cred, egid);
536
537 return (error);
538}
539
540int
541mac_check_proc_setgroups(struct proc *p, struct ucred *cred, int ngroups,
542 gid_t *gidset)
543{
544 int error;
545
546 PROC_LOCK_ASSERT(p, MA_OWNED);
547
548 MAC_CHECK(check_proc_setgroups, cred, ngroups, gidset);
549 return (error);
550}
551
552int
553mac_check_proc_setreuid(struct proc *p, struct ucred *cred, uid_t ruid,
554 uid_t euid)
555{
556 int error;
557
558 PROC_LOCK_ASSERT(p, MA_OWNED);
559
560 MAC_CHECK(check_proc_setreuid, cred, ruid, euid);
561
562 return (error);
563}
564
565int
566mac_check_proc_setregid(struct proc *proc, struct ucred *cred, gid_t rgid,
567 gid_t egid)
568{
569 int error;
570
571 PROC_LOCK_ASSERT(proc, MA_OWNED);
572
573 MAC_CHECK(check_proc_setregid, cred, rgid, egid);
574
575 return (error);
576}
577
578int
579mac_check_proc_setresuid(struct proc *p, struct ucred *cred, uid_t ruid,
580 uid_t euid, uid_t suid)
581{
582 int error;
583
584 PROC_LOCK_ASSERT(p, MA_OWNED);
585
586 MAC_CHECK(check_proc_setresuid, cred, ruid, euid, suid);
587 return (error);
588}
589
590int
591mac_check_proc_setresgid(struct proc *p, struct ucred *cred, gid_t rgid,
592 gid_t egid, gid_t sgid)
593{
594 int error;
595
596 PROC_LOCK_ASSERT(p, MA_OWNED);
597
598 MAC_CHECK(check_proc_setresgid, cred, rgid, egid, sgid);
599
600 return (error);
601}
602
603int
604mac_check_proc_wait(struct ucred *cred, struct proc *p)
605{
606 int error;
607
608 PROC_LOCK_ASSERT(p, MA_OWNED);
609
610 MAC_CHECK(check_proc_wait, cred, p);
611
612 return (error);
613}
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 * All rights reserved.
7 *
8 * This software was developed by Robert Watson and Ilmar Habibulin for the
9 * TrustedBSD Project.
10 *
11 * This software was developed for the FreeBSD Project in part by Network
12 * Associates Laboratories, the Security Research Division of Network
13 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
14 * as part of the DARPA CHATS research program.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 * 1. Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: head/sys/security/mac/mac_process.c 168955 2007-04-22 19:55:56Z rwatson $");
40
41#include "opt_mac.h"
42
43#include <sys/param.h>
44#include <sys/condvar.h>
45#include <sys/imgact.h>
46#include <sys/kernel.h>
47#include <sys/lock.h>
48#include <sys/malloc.h>
49#include <sys/mutex.h>
50#include <sys/mac.h>
51#include <sys/proc.h>
52#include <sys/sbuf.h>
53#include <sys/systm.h>
54#include <sys/vnode.h>
55#include <sys/mount.h>
56#include <sys/file.h>
57#include <sys/namei.h>
58#include <sys/sysctl.h>
59
60#include <vm/vm.h>
61#include <vm/pmap.h>
62#include <vm/vm_map.h>
63#include <vm/vm_object.h>
64
65#include <security/mac/mac_framework.h>
66#include <security/mac/mac_internal.h>
67#include <security/mac/mac_policy.h>
68
69static int mac_mmap_revocation = 1;
70SYSCTL_INT(_security_mac, OID_AUTO, mmap_revocation, CTLFLAG_RW,
71 &mac_mmap_revocation, 0, "Revoke mmap access to files on subject "
72 "relabel");
73
74static int mac_mmap_revocation_via_cow = 0;
75SYSCTL_INT(_security_mac, OID_AUTO, mmap_revocation_via_cow, CTLFLAG_RW,
76 &mac_mmap_revocation_via_cow, 0, "Revoke mmap access to files via "
77 "copy-on-write semantics, or by removing all write access");
78
79static void mac_cred_mmapped_drop_perms_recurse(struct thread *td,
80 struct ucred *cred, struct vm_map *map);
81
82struct label *
83mac_cred_label_alloc(void)
84{
85 struct label *label;
86
87 label = mac_labelzone_alloc(M_WAITOK);
88 MAC_PERFORM(init_cred_label, label);
89 return (label);
90}
91
92void
93mac_init_cred(struct ucred *cred)
94{
95
96 cred->cr_label = mac_cred_label_alloc();
97}
98
99static struct label *
100mac_proc_label_alloc(void)
101{
102 struct label *label;
103
104 label = mac_labelzone_alloc(M_WAITOK);
105 MAC_PERFORM(init_proc_label, label);
106 return (label);
107}
108
109void
110mac_init_proc(struct proc *p)
111{
112
113 p->p_label = mac_proc_label_alloc();
114}
115
116void
117mac_cred_label_free(struct label *label)
118{
119
120 MAC_PERFORM(destroy_cred_label, label);
121 mac_labelzone_free(label);
122}
123
124void
125mac_destroy_cred(struct ucred *cred)
126{
127
128 mac_cred_label_free(cred->cr_label);
129 cred->cr_label = NULL;
130}
131
132static void
133mac_proc_label_free(struct label *label)
134{
135
136 MAC_PERFORM(destroy_proc_label, label);
137 mac_labelzone_free(label);
138}
139
140void
141mac_destroy_proc(struct proc *p)
142{
143
144 mac_proc_label_free(p->p_label);
145 p->p_label = NULL;
146}
147
148int
149mac_externalize_cred_label(struct label *label, char *elements,
150 char *outbuf, size_t outbuflen)
151{
152 int error;
153
154 MAC_EXTERNALIZE(cred, label, elements, outbuf, outbuflen);
155
156 return (error);
157}
158
159int
160mac_internalize_cred_label(struct label *label, char *string)
161{
162 int error;
163
164 MAC_INTERNALIZE(cred, label, string);
165
166 return (error);
167}
168
169/*
170 * Initialize MAC label for the first kernel process, from which other kernel
171 * processes and threads are spawned.
172 */
173void
174mac_create_proc0(struct ucred *cred)
175{
176
177 MAC_PERFORM(create_proc0, cred);
178}
179
180/*
181 * Initialize MAC label for the first userland process, from which other
182 * userland processes and threads are spawned.
183 */
184void
185mac_create_proc1(struct ucred *cred)
186{
187
188 MAC_PERFORM(create_proc1, cred);
189}
190
191void
192mac_thread_userret(struct thread *td)
193{
194
195 MAC_PERFORM(thread_userret, td);
196}
197
198/*
199 * When a new process is created, its label must be initialized. Generally,
200 * this involves inheritence from the parent process, modulo possible deltas.
201 * This function allows that processing to take place.
202 */
203void
204mac_copy_cred(struct ucred *src, struct ucred *dest)
205{
206
207 MAC_PERFORM(copy_cred_label, src->cr_label, dest->cr_label);
208}
209
210int
211mac_execve_enter(struct image_params *imgp, struct mac *mac_p)
212{
213 struct label *label;
214 struct mac mac;
215 char *buffer;
216 int error;
217
218 if (mac_p == NULL)
219 return (0);
220
221 error = copyin(mac_p, &mac, sizeof(mac));
222 if (error)
223 return (error);
224
225 error = mac_check_structmac_consistent(&mac);
226 if (error)
227 return (error);
228
229 buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK);
230 error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL);
231 if (error) {
232 free(buffer, M_MACTEMP);
233 return (error);
234 }
235
236 label = mac_cred_label_alloc();
237 error = mac_internalize_cred_label(label, buffer);
238 free(buffer, M_MACTEMP);
239 if (error) {
240 mac_cred_label_free(label);
241 return (error);
242 }
243 imgp->execlabel = label;
244 return (0);
245}
246
247void
248mac_execve_exit(struct image_params *imgp)
249{
250 if (imgp->execlabel != NULL) {
251 mac_cred_label_free(imgp->execlabel);
252 imgp->execlabel = NULL;
253 }
254}
255
256/*
257 * When relabeling a process, call out to the policies for the maximum
258 * permission allowed for each object type we know about in its memory space,
259 * and revoke access (in the least surprising ways we know) when necessary.
260 * The process lock is not held here.
261 */
262void
263mac_cred_mmapped_drop_perms(struct thread *td, struct ucred *cred)
264{
265
266 /* XXX freeze all other threads */
267 mac_cred_mmapped_drop_perms_recurse(td, cred,
268 &td->td_proc->p_vmspace->vm_map);
269 /* XXX allow other threads to continue */
270}
271
272static __inline const char *
273prot2str(vm_prot_t prot)
274{
275
276 switch (prot & VM_PROT_ALL) {
277 case VM_PROT_READ:
278 return ("r--");
279 case VM_PROT_READ | VM_PROT_WRITE:
280 return ("rw-");
281 case VM_PROT_READ | VM_PROT_EXECUTE:
282 return ("r-x");
283 case VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE:
284 return ("rwx");
285 case VM_PROT_WRITE:
286 return ("-w-");
287 case VM_PROT_EXECUTE:
288 return ("--x");
289 case VM_PROT_WRITE | VM_PROT_EXECUTE:
290 return ("-wx");
291 default:
292 return ("---");
293 }
294}
295
296static void
297mac_cred_mmapped_drop_perms_recurse(struct thread *td, struct ucred *cred,
298 struct vm_map *map)
299{
300 struct vm_map_entry *vme;
301 int vfslocked, result;
302 vm_prot_t revokeperms;
303 vm_object_t backing_object, object;
304 vm_ooffset_t offset;
305 struct vnode *vp;
306 struct mount *mp;
307
308 if (!mac_mmap_revocation)
309 return;
310
311 vm_map_lock_read(map);
312 for (vme = map->header.next; vme != &map->header; vme = vme->next) {
313 if (vme->eflags & MAP_ENTRY_IS_SUB_MAP) {
314 mac_cred_mmapped_drop_perms_recurse(td, cred,
315 vme->object.sub_map);
316 continue;
317 }
318 /*
319 * Skip over entries that obviously are not shared.
320 */
321 if (vme->eflags & (MAP_ENTRY_COW | MAP_ENTRY_NOSYNC) ||
322 !vme->max_protection)
323 continue;
324 /*
325 * Drill down to the deepest backing object.
326 */
327 offset = vme->offset;
328 object = vme->object.vm_object;
329 if (object == NULL)
330 continue;
331 VM_OBJECT_LOCK(object);
332 while ((backing_object = object->backing_object) != NULL) {
333 VM_OBJECT_LOCK(backing_object);
334 offset += object->backing_object_offset;
335 VM_OBJECT_UNLOCK(object);
336 object = backing_object;
337 }
338 VM_OBJECT_UNLOCK(object);
339 /*
340 * At the moment, vm_maps and objects aren't considered by
341 * the MAC system, so only things with backing by a normal
342 * object (read: vnodes) are checked.
343 */
344 if (object->type != OBJT_VNODE)
345 continue;
346 vp = (struct vnode *)object->handle;
347 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
348 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
349 result = vme->max_protection;
350 mac_check_vnode_mmap_downgrade(cred, vp, &result);
351 VOP_UNLOCK(vp, 0, td);
352 /*
353 * Find out what maximum protection we may be allowing now
354 * but a policy needs to get removed.
355 */
356 revokeperms = vme->max_protection & ~result;
357 if (!revokeperms) {
358 VFS_UNLOCK_GIANT(vfslocked);
359 continue;
360 }
361 printf("pid %ld: revoking %s perms from %#lx:%ld "
362 "(max %s/cur %s)\n", (long)td->td_proc->p_pid,
363 prot2str(revokeperms), (u_long)vme->start,
364 (long)(vme->end - vme->start),
365 prot2str(vme->max_protection), prot2str(vme->protection));
366 vm_map_lock_upgrade(map);
367 /*
368 * This is the really simple case: if a map has more
369 * max_protection than is allowed, but it's not being
370 * actually used (that is, the current protection is still
371 * allowed), we can just wipe it out and do nothing more.
372 */
373 if ((vme->protection & revokeperms) == 0) {
374 vme->max_protection -= revokeperms;
375 } else {
376 if (revokeperms & VM_PROT_WRITE) {
377 /*
378 * In the more complicated case, flush out all
379 * pending changes to the object then turn it
380 * copy-on-write.
381 */
382 vm_object_reference(object);
383 (void) vn_start_write(vp, &mp, V_WAIT);
384 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
385 VM_OBJECT_LOCK(object);
386 vm_object_page_clean(object,
387 OFF_TO_IDX(offset),
388 OFF_TO_IDX(offset + vme->end - vme->start +
389 PAGE_MASK),
390 OBJPC_SYNC);
391 VM_OBJECT_UNLOCK(object);
392 VOP_UNLOCK(vp, 0, td);
393 vn_finished_write(mp);
394 vm_object_deallocate(object);
395 /*
396 * Why bother if there's no read permissions
397 * anymore? For the rest, we need to leave
398 * the write permissions on for COW, or
399 * remove them entirely if configured to.
400 */
401 if (!mac_mmap_revocation_via_cow) {
402 vme->max_protection &= ~VM_PROT_WRITE;
403 vme->protection &= ~VM_PROT_WRITE;
404 } if ((revokeperms & VM_PROT_READ) == 0)
405 vme->eflags |= MAP_ENTRY_COW |
406 MAP_ENTRY_NEEDS_COPY;
407 }
408 if (revokeperms & VM_PROT_EXECUTE) {
409 vme->max_protection &= ~VM_PROT_EXECUTE;
410 vme->protection &= ~VM_PROT_EXECUTE;
411 }
412 if (revokeperms & VM_PROT_READ) {
413 vme->max_protection = 0;
414 vme->protection = 0;
415 }
416 pmap_protect(map->pmap, vme->start, vme->end,
417 vme->protection & ~revokeperms);
418 vm_map_simplify_entry(map, vme);
419 }
420 vm_map_lock_downgrade(map);
421 VFS_UNLOCK_GIANT(vfslocked);
422 }
423 vm_map_unlock_read(map);
424}
425
426/*
427 * When the subject's label changes, it may require revocation of privilege
428 * to mapped objects. This can't be done on-the-fly later with a unified
429 * buffer cache.
430 */
431void
432mac_relabel_cred(struct ucred *cred, struct label *newlabel)
433{
434
435 MAC_PERFORM(relabel_cred, cred, newlabel);
436}
437
438int
439mac_check_cred_relabel(struct ucred *cred, struct label *newlabel)
440{
441 int error;
442
443 MAC_CHECK(check_cred_relabel, cred, newlabel);
444
445 return (error);
446}
447
448int
449mac_check_cred_visible(struct ucred *cr1, struct ucred *cr2)
450{
451 int error;
452
453 MAC_CHECK(check_cred_visible, cr1, cr2);
454
455 return (error);
456}
457
458int
459mac_check_proc_debug(struct ucred *cred, struct proc *p)
460{
461 int error;
462
463 PROC_LOCK_ASSERT(p, MA_OWNED);
464
465 MAC_CHECK(check_proc_debug, cred, p);
466
467 return (error);
468}
469
470int
471mac_check_proc_sched(struct ucred *cred, struct proc *p)
472{
473 int error;
474
475 PROC_LOCK_ASSERT(p, MA_OWNED);
476
477 MAC_CHECK(check_proc_sched, cred, p);
478
479 return (error);
480}
481
482int
483mac_check_proc_signal(struct ucred *cred, struct proc *p, int signum)
484{
485 int error;
486
487 PROC_LOCK_ASSERT(p, MA_OWNED);
488
489 MAC_CHECK(check_proc_signal, cred, p, signum);
490
491 return (error);
492}
493
494int
495mac_check_proc_setuid(struct proc *p, struct ucred *cred, uid_t uid)
496{
497 int error;
498
499 PROC_LOCK_ASSERT(p, MA_OWNED);
500
501 MAC_CHECK(check_proc_setuid, cred, uid);
502 return (error);
503}
504
505int
506mac_check_proc_seteuid(struct proc *p, struct ucred *cred, uid_t euid)
507{
508 int error;
509
510 PROC_LOCK_ASSERT(p, MA_OWNED);
511
512 MAC_CHECK(check_proc_seteuid, cred, euid);
513 return (error);
514}
515
516int
517mac_check_proc_setgid(struct proc *p, struct ucred *cred, gid_t gid)
518{
519 int error;
520
521 PROC_LOCK_ASSERT(p, MA_OWNED);
522
523 MAC_CHECK(check_proc_setgid, cred, gid);
524
525 return (error);
526}
527
528int
529mac_check_proc_setegid(struct proc *p, struct ucred *cred, gid_t egid)
530{
531 int error;
532
533 PROC_LOCK_ASSERT(p, MA_OWNED);
534
535 MAC_CHECK(check_proc_setegid, cred, egid);
536
537 return (error);
538}
539
540int
541mac_check_proc_setgroups(struct proc *p, struct ucred *cred, int ngroups,
542 gid_t *gidset)
543{
544 int error;
545
546 PROC_LOCK_ASSERT(p, MA_OWNED);
547
548 MAC_CHECK(check_proc_setgroups, cred, ngroups, gidset);
549 return (error);
550}
551
552int
553mac_check_proc_setreuid(struct proc *p, struct ucred *cred, uid_t ruid,
554 uid_t euid)
555{
556 int error;
557
558 PROC_LOCK_ASSERT(p, MA_OWNED);
559
560 MAC_CHECK(check_proc_setreuid, cred, ruid, euid);
561
562 return (error);
563}
564
565int
566mac_check_proc_setregid(struct proc *proc, struct ucred *cred, gid_t rgid,
567 gid_t egid)
568{
569 int error;
570
571 PROC_LOCK_ASSERT(proc, MA_OWNED);
572
573 MAC_CHECK(check_proc_setregid, cred, rgid, egid);
574
575 return (error);
576}
577
578int
579mac_check_proc_setresuid(struct proc *p, struct ucred *cred, uid_t ruid,
580 uid_t euid, uid_t suid)
581{
582 int error;
583
584 PROC_LOCK_ASSERT(p, MA_OWNED);
585
586 MAC_CHECK(check_proc_setresuid, cred, ruid, euid, suid);
587 return (error);
588}
589
590int
591mac_check_proc_setresgid(struct proc *p, struct ucred *cred, gid_t rgid,
592 gid_t egid, gid_t sgid)
593{
594 int error;
595
596 PROC_LOCK_ASSERT(p, MA_OWNED);
597
598 MAC_CHECK(check_proc_setresgid, cred, rgid, egid, sgid);
599
600 return (error);
601}
602
603int
604mac_check_proc_wait(struct ucred *cred, struct proc *p)
605{
606 int error;
607
608 PROC_LOCK_ASSERT(p, MA_OWNED);
609
610 MAC_CHECK(check_proc_wait, cred, p);
611
612 return (error);
613}