xref: /freebsd/sys/security/mac/mac_cred.c (revision 1d386b48a555f61cb7325543adbbb5c3f3407a66)
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 #include "opt_mac.h"
48 
49 #include <sys/param.h>
50 #include <sys/condvar.h>
51 #include <sys/imgact.h>
52 #include <sys/kernel.h>
53 #include <sys/lock.h>
54 #include <sys/malloc.h>
55 #include <sys/mutex.h>
56 #include <sys/mac.h>
57 #include <sys/proc.h>
58 #include <sys/sbuf.h>
59 #include <sys/sdt.h>
60 #include <sys/systm.h>
61 #include <sys/vnode.h>
62 #include <sys/mount.h>
63 #include <sys/file.h>
64 #include <sys/namei.h>
65 #include <sys/sysctl.h>
66 
67 #include <vm/vm.h>
68 #include <vm/pmap.h>
69 #include <vm/vm_map.h>
70 #include <vm/vm_object.h>
71 
72 #include <security/mac/mac_framework.h>
73 #include <security/mac/mac_internal.h>
74 #include <security/mac/mac_policy.h>
75 
76 struct label *
77 mac_cred_label_alloc(void)
78 {
79 	struct label *label;
80 
81 	label = mac_labelzone_alloc(M_WAITOK);
82 	MAC_POLICY_PERFORM(cred_init_label, label);
83 	return (label);
84 }
85 
86 void
87 mac_cred_init(struct ucred *cred)
88 {
89 
90 	if (mac_labeled & MPC_OBJECT_CRED)
91 		cred->cr_label = mac_cred_label_alloc();
92 	else
93 		cred->cr_label = NULL;
94 }
95 
96 void
97 mac_cred_label_free(struct label *label)
98 {
99 
100 	MAC_POLICY_PERFORM_NOSLEEP(cred_destroy_label, label);
101 	mac_labelzone_free(label);
102 }
103 
104 void
105 mac_cred_destroy(struct ucred *cred)
106 {
107 
108 	if (cred->cr_label != NULL) {
109 		mac_cred_label_free(cred->cr_label);
110 		cred->cr_label = NULL;
111 	}
112 }
113 
114 /*
115  * When a thread becomes an NFS server daemon, its credential may need to be
116  * updated to reflect this so that policies can recognize when file system
117  * operations originate from the network.
118  *
119  * At some point, it would be desirable if the credential used for each NFS
120  * RPC could be set based on the RPC context (i.e., source system, etc) to
121  * provide more fine-grained access control.
122  */
123 void
124 mac_cred_associate_nfsd(struct ucred *cred)
125 {
126 
127 	MAC_POLICY_PERFORM_NOSLEEP(cred_associate_nfsd, cred);
128 }
129 
130 /*
131  * Initialize MAC label for the first kernel process, from which other kernel
132  * processes and threads are spawned.
133  */
134 void
135 mac_cred_create_swapper(struct ucred *cred)
136 {
137 
138 	MAC_POLICY_PERFORM_NOSLEEP(cred_create_swapper, cred);
139 }
140 
141 /*
142  * Initialize MAC label for the first userland process, from which other
143  * userland processes and threads are spawned.
144  */
145 void
146 mac_cred_create_init(struct ucred *cred)
147 {
148 
149 	MAC_POLICY_PERFORM_NOSLEEP(cred_create_init, cred);
150 }
151 
152 int
153 mac_cred_externalize_label(struct label *label, char *elements,
154     char *outbuf, size_t outbuflen)
155 {
156 	int error;
157 
158 	MAC_POLICY_EXTERNALIZE(cred, label, elements, outbuf, outbuflen);
159 
160 	return (error);
161 }
162 
163 int
164 mac_cred_internalize_label(struct label *label, char *string)
165 {
166 	int error;
167 
168 	MAC_POLICY_INTERNALIZE(cred, label, string);
169 
170 	return (error);
171 }
172 
173 /*
174  * When a new process is created, its label must be initialized.  Generally,
175  * this involves inheritance from the parent process, modulo possible deltas.
176  * This function allows that processing to take place.
177  */
178 void
179 mac_cred_copy(struct ucred *src, struct ucred *dest)
180 {
181 
182 	MAC_POLICY_PERFORM_NOSLEEP(cred_copy_label, src->cr_label,
183 	    dest->cr_label);
184 }
185 
186 /*
187  * When the subject's label changes, it may require revocation of privilege
188  * to mapped objects.  This can't be done on-the-fly later with a unified
189  * buffer cache.
190  */
191 void
192 mac_cred_relabel(struct ucred *cred, struct label *newlabel)
193 {
194 
195 	MAC_POLICY_PERFORM_NOSLEEP(cred_relabel, cred, newlabel);
196 }
197 
198 MAC_CHECK_PROBE_DEFINE2(cred_check_relabel, "struct ucred *",
199     "struct label *");
200 
201 int
202 mac_cred_check_relabel(struct ucred *cred, struct label *newlabel)
203 {
204 	int error;
205 
206 	MAC_POLICY_CHECK_NOSLEEP(cred_check_relabel, cred, newlabel);
207 	MAC_CHECK_PROBE2(cred_check_relabel, error, cred, newlabel);
208 
209 	return (error);
210 }
211 
212 MAC_CHECK_PROBE_DEFINE2(cred_check_setuid, "struct ucred *", "uid_t");
213 
214 int
215 mac_cred_check_setuid(struct ucred *cred, uid_t uid)
216 {
217 	int error;
218 
219 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setuid, cred, uid);
220 	MAC_CHECK_PROBE2(cred_check_setuid, error, cred, uid);
221 
222 	return (error);
223 }
224 
225 MAC_CHECK_PROBE_DEFINE2(cred_check_seteuid, "struct ucred *", "uid_t");
226 
227 int
228 mac_cred_check_seteuid(struct ucred *cred, uid_t euid)
229 {
230 	int error;
231 
232 	MAC_POLICY_CHECK_NOSLEEP(cred_check_seteuid, cred, euid);
233 	MAC_CHECK_PROBE2(cred_check_seteuid, error, cred, euid);
234 
235 	return (error);
236 }
237 
238 MAC_CHECK_PROBE_DEFINE2(cred_check_setgid, "struct ucred *", "gid_t");
239 
240 int
241 mac_cred_check_setgid(struct ucred *cred, gid_t gid)
242 {
243 	int error;
244 
245 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setgid, cred, gid);
246 	MAC_CHECK_PROBE2(cred_check_setgid, error, cred, gid);
247 
248 	return (error);
249 }
250 
251 MAC_CHECK_PROBE_DEFINE2(cred_check_setegid, "struct ucred *", "gid_t");
252 
253 int
254 mac_cred_check_setegid(struct ucred *cred, gid_t egid)
255 {
256 	int error;
257 
258 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setegid, cred, egid);
259 	MAC_CHECK_PROBE2(cred_check_setegid, error, cred, egid);
260 
261 	return (error);
262 }
263 
264 MAC_CHECK_PROBE_DEFINE3(cred_check_setgroups, "struct ucred *", "int",
265     "gid_t *");
266 
267 int
268 mac_cred_check_setgroups(struct ucred *cred, int ngroups, gid_t *gidset)
269 {
270 	int error;
271 
272 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setgroups, cred, ngroups, gidset);
273 	MAC_CHECK_PROBE3(cred_check_setgroups, error, cred, ngroups, gidset);
274 
275 	return (error);
276 }
277 
278 MAC_CHECK_PROBE_DEFINE3(cred_check_setreuid, "struct ucred *", "uid_t",
279     "uid_t");
280 
281 int
282 mac_cred_check_setreuid(struct ucred *cred, uid_t ruid, uid_t euid)
283 {
284 	int error;
285 
286 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setreuid, cred, ruid, euid);
287 	MAC_CHECK_PROBE3(cred_check_setreuid, error, cred, ruid, euid);
288 
289 	return (error);
290 }
291 
292 MAC_CHECK_PROBE_DEFINE3(cred_check_setregid, "struct ucred *", "gid_t",
293     "gid_t");
294 
295 int
296 mac_cred_check_setregid(struct ucred *cred, gid_t rgid, gid_t egid)
297 {
298 	int error;
299 
300 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setregid, cred, rgid, egid);
301 	MAC_CHECK_PROBE3(cred_check_setregid, error, cred, rgid, egid);
302 
303 	return (error);
304 }
305 
306 MAC_CHECK_PROBE_DEFINE4(cred_check_setresuid, "struct ucred *", "uid_t",
307     "uid_t", "uid_t");
308 
309 int
310 mac_cred_check_setresuid(struct ucred *cred, uid_t ruid, uid_t euid,
311     uid_t suid)
312 {
313 	int error;
314 
315 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setresuid, cred, ruid, euid, suid);
316 	MAC_CHECK_PROBE4(cred_check_setresuid, error, cred, ruid, euid,
317 	    suid);
318 
319 	return (error);
320 }
321 
322 MAC_CHECK_PROBE_DEFINE4(cred_check_setresgid, "struct ucred *", "gid_t",
323     "gid_t", "gid_t");
324 
325 int
326 mac_cred_check_setresgid(struct ucred *cred, gid_t rgid, gid_t egid,
327     gid_t sgid)
328 {
329 	int error;
330 
331 	MAC_POLICY_CHECK_NOSLEEP(cred_check_setresgid, cred, rgid, egid, sgid);
332 	MAC_CHECK_PROBE4(cred_check_setresgid, error, cred, rgid, egid,
333 	    sgid);
334 
335 	return (error);
336 }
337 
338 MAC_CHECK_PROBE_DEFINE2(cred_check_visible, "struct ucred *",
339     "struct ucred *");
340 
341 int
342 mac_cred_check_visible(struct ucred *cr1, struct ucred *cr2)
343 {
344 	int error;
345 
346 	MAC_POLICY_CHECK_NOSLEEP(cred_check_visible, cr1, cr2);
347 	MAC_CHECK_PROBE2(cred_check_visible, error, cr1, cr2);
348 
349 	return (error);
350 }
351