xref: /freebsd/tests/sys/vfs/lookup_cap_dotdot.c (revision 5f4c09dd85bff675e0ca63c55ea3c517e0fddfcc)
1 /*-
2  * Copyright (c) 2016 Ed Maste <emaste@FreeBSD.org>
3  * Copyright (c) 2016 Conrad Meyer <cem@FreeBSD.org>
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 #include <sys/param.h>
29 #include <sys/capsicum.h>
30 #include <sys/sysctl.h>
31 #include <sys/stat.h>
32 
33 #include <atf-c.h>
34 #include <errno.h>
35 #include <stdlib.h>
36 #include <string.h>
37 
38 #include "freebsd_test_suite/macros.h"
39 
40 static int dirfd = -1;
41 static char *abspath;
42 
43 static void
44 touchat(int _dirfd, const char *name)
45 {
46 	int fd;
47 
48 	ATF_REQUIRE((fd = openat(_dirfd, name, O_CREAT | O_TRUNC | O_WRONLY,
49 	    0777)) >= 0);
50 	ATF_REQUIRE(close(fd) == 0);
51 }
52 
53 static void
54 prepare_dotdot_tests(void)
55 {
56 	char cwd[MAXPATHLEN];
57 
58 	ATF_REQUIRE(getcwd(cwd, sizeof(cwd)) != NULL);
59 	asprintf(&abspath, "%s/testdir/d1/f1", cwd);
60 
61 	ATF_REQUIRE(mkdir("testdir", 0777) == 0);
62 	ATF_REQUIRE((dirfd = open("testdir", O_RDONLY)) >= 0);
63 
64 	ATF_REQUIRE(mkdirat(dirfd, "d1", 0777) == 0);
65 	ATF_REQUIRE(mkdirat(dirfd, "d1/d2", 0777) == 0);
66 	ATF_REQUIRE(mkdirat(dirfd, "d1/d2/d3", 0777) == 0);
67 	touchat(dirfd, "d1/f1");
68 	touchat(dirfd, "d1/d2/f2");
69 	touchat(dirfd, "d1/d2/d3/f3");
70 	ATF_REQUIRE(symlinkat("d1/d2/d3", dirfd, "l3") == 0);
71 	ATF_REQUIRE(symlinkat("../testdir/d1", dirfd, "lup") == 0);
72 	ATF_REQUIRE(symlinkat("../..", dirfd, "d1/d2/d3/ld1") == 0);
73 	ATF_REQUIRE(symlinkat("../../f1", dirfd, "d1/d2/d3/lf1") == 0);
74 }
75 
76 static void
77 check_capsicum(void)
78 {
79 	ATF_REQUIRE_FEATURE("security_capabilities");
80 	ATF_REQUIRE_FEATURE("security_capability_mode");
81 	ATF_REQUIRE_SYSCTL_BOOL("kern.trap_enotcap", false);
82 }
83 
84 /*
85  * Positive tests
86  */
87 ATF_TC(openat__basic_positive);
88 ATF_TC_HEAD(openat__basic_positive, tc)
89 {
90 	atf_tc_set_md_var(tc, "descr", "Basic positive openat testcases");
91 }
92 
93 ATF_TC_BODY(openat__basic_positive, tc)
94 {
95 	prepare_dotdot_tests();
96 
97 	ATF_REQUIRE(openat(dirfd, "d1/d2/d3/f3", O_RDONLY) >= 0);
98 	ATF_REQUIRE(openat(dirfd, "d1/d2/d3/../../f1", O_RDONLY) >= 0);
99 	ATF_REQUIRE(openat(dirfd, "l3/f3", O_RDONLY) >= 0);
100 	ATF_REQUIRE(openat(dirfd, "l3/../../f1", O_RDONLY) >= 0);
101 	ATF_REQUIRE(openat(dirfd, "../testdir/d1/f1", O_RDONLY) >= 0);
102 	ATF_REQUIRE(openat(dirfd, "lup/f1", O_RDONLY) >= 0);
103 	ATF_REQUIRE(openat(dirfd, "l3/ld1", O_RDONLY) >= 0);
104 	ATF_REQUIRE(openat(dirfd, "l3/lf1", O_RDONLY) >= 0);
105 	ATF_REQUIRE(open(abspath, O_RDONLY) >= 0);
106 	ATF_REQUIRE(openat(dirfd, abspath, O_RDONLY) >= 0);
107 }
108 
109 ATF_TC(lookup_cap_dotdot__basic);
110 ATF_TC_HEAD(lookup_cap_dotdot__basic, tc)
111 {
112 	atf_tc_set_md_var(tc, "descr",
113 	    "Validate cap-mode (testdir)/d1/.. lookup");
114 }
115 
116 ATF_TC_BODY(lookup_cap_dotdot__basic, tc)
117 {
118 	cap_rights_t rights;
119 
120 	check_capsicum();
121 	prepare_dotdot_tests();
122 
123 	cap_rights_init(&rights, CAP_LOOKUP, CAP_READ);
124 	ATF_REQUIRE(cap_rights_limit(dirfd, &rights) >= 0);
125 
126 	ATF_REQUIRE(cap_enter() >= 0);
127 
128 	ATF_REQUIRE_MSG(openat(dirfd, "d1/..", O_RDONLY) >= 0, "%s",
129 	    strerror(errno));
130 }
131 
132 ATF_TC(lookup_cap_dotdot__advanced);
133 ATF_TC_HEAD(lookup_cap_dotdot__advanced, tc)
134 {
135 	atf_tc_set_md_var(tc, "descr",
136 	    "Validate cap-mode (testdir)/d1/.. lookup");
137 }
138 
139 ATF_TC_BODY(lookup_cap_dotdot__advanced, tc)
140 {
141 	cap_rights_t rights;
142 
143 	check_capsicum();
144 	prepare_dotdot_tests();
145 
146 	cap_rights_init(&rights, CAP_LOOKUP, CAP_READ);
147 	ATF_REQUIRE(cap_rights_limit(dirfd, &rights) >= 0);
148 
149 	ATF_REQUIRE(cap_enter() >= 0);
150 
151 	ATF_REQUIRE(openat(dirfd, "d1/d2/d3/../../f1", O_RDONLY) >= 0);
152 	ATF_REQUIRE(openat(dirfd, "l3/../../f1", O_RDONLY) >= 0);
153 	ATF_REQUIRE(openat(dirfd, "l3/ld1", O_RDONLY) >= 0);
154 	ATF_REQUIRE(openat(dirfd, "l3/lf1", O_RDONLY) >= 0);
155 }
156 
157 /*
158  * Negative tests
159  */
160 ATF_TC(openat__basic_negative);
161 ATF_TC_HEAD(openat__basic_negative, tc)
162 {
163 	atf_tc_set_md_var(tc, "descr", "Basic negative openat testcases");
164 }
165 
166 ATF_TC_BODY(openat__basic_negative, tc)
167 {
168 	prepare_dotdot_tests();
169 
170 	ATF_REQUIRE_ERRNO(ENOENT,
171 	    openat(dirfd, "does-not-exist", O_RDONLY) < 0);
172 	ATF_REQUIRE_ERRNO(ENOENT,
173 	    openat(dirfd, "l3/does-not-exist", O_RDONLY) < 0);
174 }
175 
176 ATF_TC(capmode__negative);
177 ATF_TC_HEAD(capmode__negative, tc)
178 {
179 	atf_tc_set_md_var(tc, "descr", "Negative Capability mode testcases");
180 }
181 
182 ATF_TC_BODY(capmode__negative, tc)
183 {
184 	int subdirfd;
185 
186 	check_capsicum();
187 	prepare_dotdot_tests();
188 
189 	ATF_REQUIRE(cap_enter() == 0);
190 
191 	/* open() not permitted in capability mode */
192 	ATF_REQUIRE_ERRNO(ECAPMODE, open("testdir", O_RDONLY) < 0);
193 
194 	/* AT_FDCWD not permitted in capability mode */
195 	ATF_REQUIRE_ERRNO(ECAPMODE, openat(AT_FDCWD, "d1/f1", O_RDONLY) < 0);
196 
197 	/* Relative path above dirfd not capable */
198 	ATF_REQUIRE_ERRNO(ENOTCAPABLE, openat(dirfd, "..", O_RDONLY) < 0);
199 	ATF_REQUIRE((subdirfd = openat(dirfd, "l3", O_RDONLY)) >= 0);
200 	ATF_REQUIRE_ERRNO(ENOTCAPABLE,
201 	    openat(subdirfd, "../../f1", O_RDONLY) < 0);
202 
203 	/* Absolute paths not capable */
204 	ATF_REQUIRE_ERRNO(ENOTCAPABLE, openat(dirfd, abspath, O_RDONLY) < 0);
205 
206 	/* Symlink above dirfd */
207 	ATF_REQUIRE_ERRNO(ENOTCAPABLE, openat(dirfd, "lup/f1", O_RDONLY) < 0);
208 }
209 
210 ATF_TC(lookup_cap_dotdot__negative);
211 ATF_TC_HEAD(lookup_cap_dotdot__negative, tc)
212 {
213 	atf_tc_set_md_var(tc, "descr",
214 	    "Validate cap-mode (testdir)/.. lookup fails");
215 }
216 
217 ATF_TC_BODY(lookup_cap_dotdot__negative, tc)
218 {
219 	cap_rights_t rights;
220 
221 	check_capsicum();
222 	prepare_dotdot_tests();
223 
224 	cap_rights_init(&rights, CAP_LOOKUP, CAP_READ);
225 	ATF_REQUIRE(cap_rights_limit(dirfd, &rights) >= 0);
226 
227 	ATF_REQUIRE(cap_enter() >= 0);
228 
229 	ATF_REQUIRE_ERRNO(ENOTCAPABLE, openat(dirfd, "..", O_RDONLY) < 0);
230 	ATF_REQUIRE_ERRNO(ENOTCAPABLE, openat(dirfd, "d1/../..", O_RDONLY) < 0);
231 	ATF_REQUIRE_ERRNO(ENOTCAPABLE, openat(dirfd, "../testdir/d1/f1", O_RDONLY) < 0);
232 }
233 
234 ATF_TC(lookup_cap_dotdot__root);
235 ATF_TC_HEAD(lookup_cap_dotdot__root, tc)
236 {
237 	atf_tc_set_md_var(tc, "descr", "Validate cap-mode /.. lookup fails");
238 }
239 
240 ATF_TC_BODY(lookup_cap_dotdot__root, tc)
241 {
242 	int dfd, dfd2;
243 
244 	check_capsicum();
245 
246 	dfd = open("/", O_DIRECTORY);
247 	ATF_REQUIRE(dfd >= 0);
248 
249 	dfd2 = openat(dfd, "..", O_DIRECTORY);
250 	ATF_REQUIRE(dfd2 >= 0);
251 	ATF_REQUIRE(close(dfd2) == 0);
252 
253 	ATF_REQUIRE(cap_enter() >= 0);
254 
255 	dfd2 = openat(dfd, "..", O_DIRECTORY);
256 	ATF_REQUIRE_ERRNO(ENOTCAPABLE, openat(dfd, "..", O_DIRECTORY));
257 }
258 
259 ATF_TP_ADD_TCS(tp)
260 {
261 
262 	ATF_TP_ADD_TC(tp, openat__basic_positive);
263 	ATF_TP_ADD_TC(tp, openat__basic_negative);
264 
265 	ATF_TP_ADD_TC(tp, capmode__negative);
266 
267 	ATF_TP_ADD_TC(tp, lookup_cap_dotdot__basic);
268 	ATF_TP_ADD_TC(tp, lookup_cap_dotdot__advanced);
269 	ATF_TP_ADD_TC(tp, lookup_cap_dotdot__negative);
270 	ATF_TP_ADD_TC(tp, lookup_cap_dotdot__root);
271 
272 	return (atf_no_error());
273 }
274