xref: /freebsd/tests/sys/vfs/lookup_cap_dotdot.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
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 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/capsicum.h>
32 #include <sys/sysctl.h>
33 #include <sys/stat.h>
34 
35 #include <atf-c.h>
36 #include <errno.h>
37 #include <stdlib.h>
38 #include <string.h>
39 
40 #include "freebsd_test_suite/macros.h"
41 
42 static int dirfd = -1;
43 static char *abspath;
44 
45 static void
46 touchat(int _dirfd, const char *name)
47 {
48 	int fd;
49 
50 	ATF_REQUIRE((fd = openat(_dirfd, name, O_CREAT | O_TRUNC | O_WRONLY,
51 	    0777)) >= 0);
52 	ATF_REQUIRE(close(fd) == 0);
53 }
54 
55 static void
56 prepare_dotdot_tests(void)
57 {
58 	char cwd[MAXPATHLEN];
59 
60 	ATF_REQUIRE(getcwd(cwd, sizeof(cwd)) != NULL);
61 	asprintf(&abspath, "%s/testdir/d1/f1", cwd);
62 
63 	ATF_REQUIRE(mkdir("testdir", 0777) == 0);
64 	ATF_REQUIRE((dirfd = open("testdir", O_RDONLY)) >= 0);
65 
66 	ATF_REQUIRE(mkdirat(dirfd, "d1", 0777) == 0);
67 	ATF_REQUIRE(mkdirat(dirfd, "d1/d2", 0777) == 0);
68 	ATF_REQUIRE(mkdirat(dirfd, "d1/d2/d3", 0777) == 0);
69 	touchat(dirfd, "d1/f1");
70 	touchat(dirfd, "d1/d2/f2");
71 	touchat(dirfd, "d1/d2/d3/f3");
72 	ATF_REQUIRE(symlinkat("d1/d2/d3", dirfd, "l3") == 0);
73 	ATF_REQUIRE(symlinkat("../testdir/d1", dirfd, "lup") == 0);
74 	ATF_REQUIRE(symlinkat("../..", dirfd, "d1/d2/d3/ld1") == 0);
75 	ATF_REQUIRE(symlinkat("../../f1", dirfd, "d1/d2/d3/lf1") == 0);
76 }
77 
78 static void
79 check_capsicum(void)
80 {
81 	ATF_REQUIRE_FEATURE("security_capabilities");
82 	ATF_REQUIRE_FEATURE("security_capability_mode");
83 }
84 
85 /*
86  * Positive tests
87  */
88 ATF_TC(openat__basic_positive);
89 ATF_TC_HEAD(openat__basic_positive, tc)
90 {
91 	atf_tc_set_md_var(tc, "descr", "Basic positive openat testcases");
92 }
93 
94 ATF_TC_BODY(openat__basic_positive, tc)
95 {
96 	prepare_dotdot_tests();
97 
98 	ATF_REQUIRE(openat(dirfd, "d1/d2/d3/f3", O_RDONLY) >= 0);
99 	ATF_REQUIRE(openat(dirfd, "d1/d2/d3/../../f1", O_RDONLY) >= 0);
100 	ATF_REQUIRE(openat(dirfd, "l3/f3", O_RDONLY) >= 0);
101 	ATF_REQUIRE(openat(dirfd, "l3/../../f1", O_RDONLY) >= 0);
102 	ATF_REQUIRE(openat(dirfd, "../testdir/d1/f1", O_RDONLY) >= 0);
103 	ATF_REQUIRE(openat(dirfd, "lup/f1", O_RDONLY) >= 0);
104 	ATF_REQUIRE(openat(dirfd, "l3/ld1", O_RDONLY) >= 0);
105 	ATF_REQUIRE(openat(dirfd, "l3/lf1", O_RDONLY) >= 0);
106 	ATF_REQUIRE(open(abspath, O_RDONLY) >= 0);
107 	ATF_REQUIRE(openat(dirfd, abspath, O_RDONLY) >= 0);
108 }
109 
110 ATF_TC(lookup_cap_dotdot__basic);
111 ATF_TC_HEAD(lookup_cap_dotdot__basic, tc)
112 {
113 	atf_tc_set_md_var(tc, "descr",
114 	    "Validate cap-mode (testdir)/d1/.. lookup");
115 }
116 
117 ATF_TC_BODY(lookup_cap_dotdot__basic, tc)
118 {
119 	cap_rights_t rights;
120 
121 	check_capsicum();
122 	prepare_dotdot_tests();
123 
124 	cap_rights_init(&rights, CAP_LOOKUP, CAP_READ);
125 	ATF_REQUIRE(cap_rights_limit(dirfd, &rights) >= 0);
126 
127 	atf_tc_expect_signal(SIGABRT, "needs change done upstream in atf/kyua according to cem: bug 215690");
128 
129 	ATF_REQUIRE(cap_enter() >= 0);
130 
131 	ATF_REQUIRE_MSG(openat(dirfd, "d1/..", O_RDONLY) >= 0, "%s",
132 	    strerror(errno));
133 }
134 
135 ATF_TC(lookup_cap_dotdot__advanced);
136 ATF_TC_HEAD(lookup_cap_dotdot__advanced, tc)
137 {
138 	atf_tc_set_md_var(tc, "descr",
139 	    "Validate cap-mode (testdir)/d1/.. lookup");
140 }
141 
142 ATF_TC_BODY(lookup_cap_dotdot__advanced, tc)
143 {
144 	cap_rights_t rights;
145 
146 	check_capsicum();
147 	prepare_dotdot_tests();
148 
149 	atf_tc_expect_signal(SIGABRT, "needs change done upstream in atf/kyua according to cem: bug 215690");
150 
151 	cap_rights_init(&rights, CAP_LOOKUP, CAP_READ);
152 	ATF_REQUIRE(cap_rights_limit(dirfd, &rights) >= 0);
153 
154 	ATF_REQUIRE(cap_enter() >= 0);
155 
156 	ATF_REQUIRE(openat(dirfd, "d1/d2/d3/../../f1", O_RDONLY) >= 0);
157 	ATF_REQUIRE(openat(dirfd, "l3/../../f1", O_RDONLY) >= 0);
158 	ATF_REQUIRE(openat(dirfd, "l3/ld1", O_RDONLY) >= 0);
159 	ATF_REQUIRE(openat(dirfd, "l3/lf1", O_RDONLY) >= 0);
160 }
161 
162 /*
163  * Negative tests
164  */
165 ATF_TC(openat__basic_negative);
166 ATF_TC_HEAD(openat__basic_negative, tc)
167 {
168 	atf_tc_set_md_var(tc, "descr", "Basic negative openat testcases");
169 }
170 
171 ATF_TC_BODY(openat__basic_negative, tc)
172 {
173 	prepare_dotdot_tests();
174 
175 	ATF_REQUIRE_ERRNO(ENOENT,
176 	    openat(dirfd, "does-not-exist", O_RDONLY) < 0);
177 	ATF_REQUIRE_ERRNO(ENOENT,
178 	    openat(dirfd, "l3/does-not-exist", O_RDONLY) < 0);
179 }
180 
181 ATF_TC(capmode__negative);
182 ATF_TC_HEAD(capmode__negative, tc)
183 {
184 	atf_tc_set_md_var(tc, "descr", "Negative Capability mode testcases");
185 }
186 
187 ATF_TC_BODY(capmode__negative, tc)
188 {
189 	int subdirfd;
190 
191 	check_capsicum();
192 	prepare_dotdot_tests();
193 
194 	atf_tc_expect_signal(SIGABRT, "needs change done upstream in atf/kyua according to cem: bug 215690");
195 
196 	ATF_REQUIRE(cap_enter() == 0);
197 
198 	/* open() not permitted in capability mode */
199 	ATF_REQUIRE_ERRNO(ECAPMODE, open("testdir", O_RDONLY) < 0);
200 
201 	/* AT_FDCWD not permitted in capability mode */
202 	ATF_REQUIRE_ERRNO(ECAPMODE, openat(AT_FDCWD, "d1/f1", O_RDONLY) < 0);
203 
204 	/* Relative path above dirfd not capable */
205 	ATF_REQUIRE_ERRNO(ENOTCAPABLE, openat(dirfd, "..", O_RDONLY) < 0);
206 	ATF_REQUIRE((subdirfd = openat(dirfd, "l3", O_RDONLY)) >= 0);
207 	ATF_REQUIRE_ERRNO(ENOTCAPABLE,
208 	    openat(subdirfd, "../../f1", O_RDONLY) < 0);
209 
210 	/* Absolute paths not capable */
211 	ATF_REQUIRE_ERRNO(ENOTCAPABLE, openat(dirfd, abspath, O_RDONLY) < 0);
212 
213 	/* Symlink above dirfd */
214 	ATF_REQUIRE_ERRNO(ENOTCAPABLE, openat(dirfd, "lup/f1", O_RDONLY) < 0);
215 }
216 
217 ATF_TC(lookup_cap_dotdot__negative);
218 ATF_TC_HEAD(lookup_cap_dotdot__negative, tc)
219 {
220 	atf_tc_set_md_var(tc, "descr",
221 	    "Validate cap-mode (testdir)/.. lookup fails");
222 }
223 
224 ATF_TC_BODY(lookup_cap_dotdot__negative, tc)
225 {
226 	cap_rights_t rights;
227 
228 	check_capsicum();
229 	prepare_dotdot_tests();
230 
231 	cap_rights_init(&rights, CAP_LOOKUP, CAP_READ);
232 	ATF_REQUIRE(cap_rights_limit(dirfd, &rights) >= 0);
233 
234 	atf_tc_expect_signal(SIGABRT, "needs change done upstream in atf/kyua according to cem: bug 215690");
235 
236 	ATF_REQUIRE(cap_enter() >= 0);
237 
238 	ATF_REQUIRE_ERRNO(ENOTCAPABLE, openat(dirfd, "..", O_RDONLY) < 0);
239 	ATF_REQUIRE_ERRNO(ENOTCAPABLE, openat(dirfd, "d1/../..", O_RDONLY) < 0);
240 	ATF_REQUIRE_ERRNO(ENOTCAPABLE, openat(dirfd, "../testdir/d1/f1", O_RDONLY) < 0);
241 }
242 
243 ATF_TP_ADD_TCS(tp)
244 {
245 
246 	ATF_TP_ADD_TC(tp, openat__basic_positive);
247 	ATF_TP_ADD_TC(tp, openat__basic_negative);
248 
249 	ATF_TP_ADD_TC(tp, capmode__negative);
250 
251 	ATF_TP_ADD_TC(tp, lookup_cap_dotdot__basic);
252 	ATF_TP_ADD_TC(tp, lookup_cap_dotdot__advanced);
253 	ATF_TP_ADD_TC(tp, lookup_cap_dotdot__negative);
254 
255 	return (atf_no_error());
256 }
257