xref: /freebsd/sys/security/mac/mac_cred.c (revision aa0a1e58f0189b0fde359a8bda032887e72057fa)
1 /*-
2  * Copyright (c) 1999-2002, 2008-2009 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  * Copyright (c) 2008 Apple Inc.
8  * All rights reserved.
9  *
10  * This software was developed by Robert Watson and Ilmar Habibulin for the
11  * TrustedBSD Project.
12  *
13  * This software was developed for the FreeBSD Project in part by Network
14  * Associates Laboratories, the Security Research Division of Network
15  * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
16  * as part of the DARPA CHATS research program.
17  *
18  * This software was enhanced by SPARTA ISSO under SPAWAR contract
19  * N66001-04-C-6019 ("SEFOS").
20  *
21  * This software was developed at the University of Cambridge Computer
22  * Laboratory with support from a grant from Google, Inc.
23  *
24  * Redistribution and use in source and binary forms, with or without
25  * modification, are permitted provided that the following conditions
26  * are met:
27  * 1. Redistributions of source code must retain the above copyright
28  *    notice, this list of conditions and the following disclaimer.
29  * 2. Redistributions in binary form must reproduce the above copyright
30  *    notice, this list of conditions and the following disclaimer in the
31  *    documentation and/or other materials provided with the distribution.
32  *
33  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
34  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
35  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
36  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
37  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
38  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
39  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
41  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
42  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
43  * SUCH DAMAGE.
44  */
45 
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48 
49 #include "opt_kdtrace.h"
50 #include "opt_mac.h"
51 
52 #include <sys/param.h>
53 #include <sys/condvar.h>
54 #include <sys/imgact.h>
55 #include <sys/kernel.h>
56 #include <sys/lock.h>
57 #include <sys/malloc.h>
58 #include <sys/mutex.h>
59 #include <sys/mac.h>
60 #include <sys/proc.h>
61 #include <sys/sbuf.h>
62 #include <sys/sdt.h>
63 #include <sys/systm.h>
64 #include <sys/vnode.h>
65 #include <sys/mount.h>
66 #include <sys/file.h>
67 #include <sys/namei.h>
68 #include <sys/sysctl.h>
69 
70 #include <vm/vm.h>
71 #include <vm/pmap.h>
72 #include <vm/vm_map.h>
73 #include <vm/vm_object.h>
74 
75 #include <security/mac/mac_framework.h>
76 #include <security/mac/mac_internal.h>
77 #include <security/mac/mac_policy.h>
78 
79 struct label *
80 mac_cred_label_alloc(void)
81 {
82 	struct label *label;
83 
84 	label = mac_labelzone_alloc(M_WAITOK);
85 	MAC_POLICY_PERFORM(cred_init_label, label);
86 	return (label);
87 }
88 
89 void
90 mac_cred_init(struct ucred *cred)
91 {
92 
93 	if (mac_labeled & MPC_OBJECT_CRED)
94 		cred->cr_label = mac_cred_label_alloc();
95 	else
96 		cred->cr_label = NULL;
97 }
98 
99 void
100 mac_cred_label_free(struct label *label)
101 {
102 
103 	MAC_POLICY_PERFORM_NOSLEEP(cred_destroy_label, label);
104 	mac_labelzone_free(label);
105 }
106 
107 void
108 mac_cred_destroy(struct ucred *cred)
109 {
110 
111 	if (cred->cr_label != NULL) {
112 		mac_cred_label_free(cred->cr_label);
113 		cred->cr_label = NULL;
114 	}
115 }
116 
117 /*
118  * When a thread becomes an NFS server daemon, its credential may need to be
119  * updated to reflect this so that policies can recognize when file system
120  * operations originate from the network.
121  *
122  * At some point, it would be desirable if the credential used for each NFS
123  * RPC could be set based on the RPC context (i.e., source system, etc) to
124  * provide more fine-grained access control.
125  */
126 void
127 mac_cred_associate_nfsd(struct ucred *cred)
128 {
129 
130 	MAC_POLICY_PERFORM_NOSLEEP(cred_associate_nfsd, cred);
131 }
132 
133 /*
134  * Initialize MAC label for the first kernel process, from which other kernel
135  * processes and threads are spawned.
136  */
137 void
138 mac_cred_create_swapper(struct ucred *cred)
139 {
140 
141 	MAC_POLICY_PERFORM_NOSLEEP(cred_create_swapper, cred);
142 }
143 
144 /*
145  * Initialize MAC label for the first userland process, from which other
146  * userland processes and threads are spawned.
147  */
148 void
149 mac_cred_create_init(struct ucred *cred)
150 {
151 
152 	MAC_POLICY_PERFORM_NOSLEEP(cred_create_init, cred);
153 }
154 
155 int
156 mac_cred_externalize_label(struct label *label, char *elements,
157     char *outbuf, size_t outbuflen)
158 {
159 	int error;
160 
161 	MAC_POLICY_EXTERNALIZE(cred, label, elements, outbuf, outbuflen);
162 
163 	return (error);
164 }
165 
166 int
167 mac_cred_internalize_label(struct label *label, char *string)
168 {
169 	int error;
170 
171 	MAC_POLICY_INTERNALIZE(cred, label, string);
172 
173 	return (error);
174 }
175 
176 /*
177  * When a new process is created, its label must be initialized.  Generally,
178  * this involves inheritence from the parent process, modulo possible deltas.
179  * This function allows that processing to take place.
180  */
181 void
182 mac_cred_copy(struct ucred *src, struct ucred *dest)
183 {
184 
185 	MAC_POLICY_PERFORM_NOSLEEP(cred_copy_label, src->cr_label,
186 	    dest->cr_label);
187 }
188 
189 /*
190  * When the subject's label changes, it may require revocation of privilege
191  * to mapped objects.  This can't be done on-the-fly later with a unified
192  * buffer cache.
193  */
194 void
195 mac_cred_relabel(struct ucred *cred, struct label *newlabel)
196 {
197 
198 	MAC_POLICY_PERFORM_NOSLEEP(cred_relabel, cred, newlabel);
199 }
200 
201 MAC_CHECK_PROBE_DEFINE2(cred_check_relabel, "struct ucred *",
202     "struct label *");
203 
204 int
205 mac_cred_check_relabel(struct ucred *cred, struct label *newlabel)
206 {
207 	int error;
208 
209 	MAC_POLICY_CHECK_NOSLEEP(cred_check_relabel, cred, newlabel);
210 	MAC_CHECK_PROBE2(cred_check_relabel, error, cred, newlabel);
211 
212 	return (error);
213 }
214 
215 MAC_CHECK_PROBE_DEFINE2(cred_check_setuid, "struct ucred *", "uid_t");
216 
217 int
218 mac_cred_check_setuid(struct ucred *cred, uid_t uid)
219 {
220 	int error;
221 
222 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setuid, cred, uid);
223 	MAC_CHECK_PROBE2(cred_check_setuid, error, cred, uid);
224 
225 	return (error);
226 }
227 
228 MAC_CHECK_PROBE_DEFINE2(cred_check_seteuid, "struct ucred *", "uid_t");
229 
230 int
231 mac_cred_check_seteuid(struct ucred *cred, uid_t euid)
232 {
233 	int error;
234 
235 	MAC_POLICY_CHECK_NOSLEEP(cred_check_seteuid, cred, euid);
236 	MAC_CHECK_PROBE2(cred_check_seteuid, error, cred, euid);
237 
238 	return (error);
239 }
240 
241 MAC_CHECK_PROBE_DEFINE2(cred_check_setgid, "struct ucred *", "gid_t");
242 
243 int
244 mac_cred_check_setgid(struct ucred *cred, gid_t gid)
245 {
246 	int error;
247 
248 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setgid, cred, gid);
249 	MAC_CHECK_PROBE2(cred_check_setgid, error, cred, gid);
250 
251 	return (error);
252 }
253 
254 MAC_CHECK_PROBE_DEFINE2(cred_check_setegid, "struct ucred *", "gid_t");
255 
256 int
257 mac_cred_check_setegid(struct ucred *cred, gid_t egid)
258 {
259 	int error;
260 
261 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setegid, cred, egid);
262 	MAC_CHECK_PROBE2(cred_check_setegid, error, cred, egid);
263 
264 	return (error);
265 }
266 
267 MAC_CHECK_PROBE_DEFINE3(cred_check_setgroups, "struct ucred *", "int",
268     "gid_t *");
269 
270 int
271 mac_cred_check_setgroups(struct ucred *cred, int ngroups, gid_t *gidset)
272 {
273 	int error;
274 
275 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setgroups, cred, ngroups, gidset);
276 	MAC_CHECK_PROBE3(cred_check_setgroups, error, cred, ngroups, gidset);
277 
278 	return (error);
279 }
280 
281 MAC_CHECK_PROBE_DEFINE3(cred_check_setreuid, "struct ucred *", "uid_t",
282     "uid_t");
283 
284 int
285 mac_cred_check_setreuid(struct ucred *cred, uid_t ruid, uid_t euid)
286 {
287 	int error;
288 
289 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setreuid, cred, ruid, euid);
290 	MAC_CHECK_PROBE3(cred_check_setreuid, error, cred, ruid, euid);
291 
292 	return (error);
293 }
294 
295 MAC_CHECK_PROBE_DEFINE3(cred_check_setregid, "struct ucred *", "gid_t",
296     "gid_t");
297 
298 int
299 mac_cred_check_setregid(struct ucred *cred, gid_t rgid, gid_t egid)
300 {
301 	int error;
302 
303 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setregid, cred, rgid, egid);
304 	MAC_CHECK_PROBE3(cred_check_setregid, error, cred, rgid, egid);
305 
306 	return (error);
307 }
308 
309 MAC_CHECK_PROBE_DEFINE4(cred_check_setresuid, "struct ucred *", "uid_t",
310     "uid_t", "uid_t");
311 
312 int
313 mac_cred_check_setresuid(struct ucred *cred, uid_t ruid, uid_t euid,
314     uid_t suid)
315 {
316 	int error;
317 
318 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setresuid, cred, ruid, euid, suid);
319 	MAC_CHECK_PROBE4(cred_check_setresuid, error, cred, ruid, euid,
320 	    suid);
321 
322 	return (error);
323 }
324 
325 MAC_CHECK_PROBE_DEFINE4(cred_check_setresgid, "struct ucred *", "gid_t",
326     "gid_t", "gid_t");
327 
328 int
329 mac_cred_check_setresgid(struct ucred *cred, gid_t rgid, gid_t egid,
330     gid_t sgid)
331 {
332 	int error;
333 
334 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setresgid, cred, rgid, egid, sgid);
335 	MAC_CHECK_PROBE4(cred_check_setresgid, error, cred, rgid, egid,
336 	    sgid);
337 
338 	return (error);
339 }
340 
341 MAC_CHECK_PROBE_DEFINE2(cred_check_visible, "struct ucred *",
342     "struct ucred *");
343 
344 int
345 mac_cred_check_visible(struct ucred *cr1, struct ucred *cr2)
346 {
347 	int error;
348 
349 	MAC_POLICY_CHECK_NOSLEEP(cred_check_visible, cr1, cr2);
350 	MAC_CHECK_PROBE2(cred_check_visible, error, cr1, cr2);
351 
352 	return (error);
353 }
354