xref: /freebsd/sys/compat/linux/linux_uid16.c (revision 2b833162) 
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2001  The FreeBSD Project
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/fcntl.h>
34 #include <sys/lock.h>
35 #include <sys/malloc.h>
36 #include <sys/mutex.h>
37 #include <sys/priv.h>
38 #include <sys/proc.h>
39 #include <sys/syscallsubr.h>
40 #include <sys/sysproto.h>
41 
42 #ifdef COMPAT_LINUX32
43 #include <machine/../linux32/linux.h>
44 #include <machine/../linux32/linux32_proto.h>
45 #else
46 #include <machine/../linux/linux.h>
47 #include <machine/../linux/linux_proto.h>
48 #endif
49 
50 #include <compat/linux/linux_dtrace.h>
51 #include <compat/linux/linux_util.h>
52 
53 /* DTrace init */
54 LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE);
55 
56 /**
57  * DTrace probes in this module.
58  */
59 LIN_SDT_PROBE_DEFINE1(uid16, linux_chown16, conv_path, "char *");
60 LIN_SDT_PROBE_DEFINE1(uid16, linux_lchown16, conv_path, "char *");
61 LIN_SDT_PROBE_DEFINE1(uid16, linux_setgroups16, copyin_error, "int");
62 LIN_SDT_PROBE_DEFINE1(uid16, linux_setgroups16, priv_check_cred_error, "int");
63 LIN_SDT_PROBE_DEFINE1(uid16, linux_getgroups16, copyout_error, "int");
64 
65 DUMMY(setfsuid16);
66 DUMMY(setfsgid16);
67 DUMMY(getresuid16);
68 DUMMY(getresgid16);
69 
70 #define	CAST_NOCHG(x)	((x == 0xFFFF) ? -1 : x)
71 
72 int
73 linux_chown16(struct thread *td, struct linux_chown16_args *args)
74 {
75 	char *path;
76 	int error;
77 
78 	if (!LUSECONVPATH(td) && !SDT_PROBES_ENABLED()) {
79 		error = kern_fchownat(td, AT_FDCWD, args->path, UIO_USERSPACE,
80 		    CAST_NOCHG(args->uid), CAST_NOCHG(args->gid), 0);
81 	} else {
82 		LCONVPATHEXIST(args->path, &path);
83 		/*
84 		 * The DTrace probes have to be after the LCONVPATHEXIST, as
85 		 * LCONVPATHEXIST may return on its own and we do not want to
86 		 * have a stray entry without the corresponding return.
87 		 */
88 		LIN_SDT_PROBE1(uid16, linux_chown16, conv_path, path);
89 
90 		error = kern_fchownat(td, AT_FDCWD, path, UIO_SYSSPACE,
91 		    CAST_NOCHG(args->uid), CAST_NOCHG(args->gid), 0);
92 		LFREEPATH(path);
93 	}
94 	return (error);
95 }
96 
97 int
98 linux_lchown16(struct thread *td, struct linux_lchown16_args *args)
99 {
100 	char *path;
101 	int error;
102 
103 	if (!LUSECONVPATH(td) && !SDT_PROBES_ENABLED()) {
104 		error = kern_fchownat(td, AT_FDCWD, args->path, UIO_USERSPACE,
105 		    CAST_NOCHG(args->uid), CAST_NOCHG(args->gid), AT_SYMLINK_NOFOLLOW);
106 	} else {
107 		LCONVPATHEXIST(args->path, &path);
108 
109 		/*
110 		 * The DTrace probes have to be after the LCONVPATHEXIST, as
111 		 * LCONVPATHEXIST may return on its own and we do not want to
112 		 * have a stray entry without the corresponding return.
113 		 */
114 		LIN_SDT_PROBE1(uid16, linux_lchown16, conv_path, path);
115 
116 		error = kern_fchownat(td, AT_FDCWD, path, UIO_SYSSPACE,
117 		    CAST_NOCHG(args->uid), CAST_NOCHG(args->gid), AT_SYMLINK_NOFOLLOW);
118 		LFREEPATH(path);
119 	}
120 	return (error);
121 }
122 
123 int
124 linux_setgroups16(struct thread *td, struct linux_setgroups16_args *args)
125 {
126 	struct ucred *newcred, *oldcred;
127 	l_gid16_t *linux_gidset;
128 	gid_t *bsd_gidset;
129 	int ngrp, error;
130 	struct proc *p;
131 
132 	ngrp = args->gidsetsize;
133 	if (ngrp < 0 || ngrp >= ngroups_max + 1)
134 		return (EINVAL);
135 	linux_gidset = malloc(ngrp * sizeof(*linux_gidset), M_LINUX, M_WAITOK);
136 	error = copyin(args->gidset, linux_gidset, ngrp * sizeof(l_gid16_t));
137 	if (error) {
138 		LIN_SDT_PROBE1(uid16, linux_setgroups16, copyin_error, error);
139 		free(linux_gidset, M_LINUX);
140 		return (error);
141 	}
142 	newcred = crget();
143 	p = td->td_proc;
144 	PROC_LOCK(p);
145 	oldcred = crcopysafe(p, newcred);
146 
147 	/*
148 	 * cr_groups[0] holds egid. Setting the whole set from
149 	 * the supplied set will cause egid to be changed too.
150 	 * Keep cr_groups[0] unchanged to prevent that.
151 	 */
152 
153 	if ((error = priv_check_cred(oldcred, PRIV_CRED_SETGROUPS)) != 0) {
154 		PROC_UNLOCK(p);
155 		crfree(newcred);
156 
157 		LIN_SDT_PROBE1(uid16, linux_setgroups16, priv_check_cred_error,
158 		    error);
159 		goto out;
160 	}
161 
162 	if (ngrp > 0) {
163 		newcred->cr_ngroups = ngrp + 1;
164 
165 		bsd_gidset = newcred->cr_groups;
166 		ngrp--;
167 		while (ngrp >= 0) {
168 			bsd_gidset[ngrp + 1] = linux_gidset[ngrp];
169 			ngrp--;
170 		}
171 	}
172 	else
173 		newcred->cr_ngroups = 1;
174 
175 	setsugid(td->td_proc);
176 	proc_set_cred(p, newcred);
177 	PROC_UNLOCK(p);
178 	crfree(oldcred);
179 	error = 0;
180 out:
181 	free(linux_gidset, M_LINUX);
182 
183 	return (error);
184 }
185 
186 int
187 linux_getgroups16(struct thread *td, struct linux_getgroups16_args *args)
188 {
189 	struct ucred *cred;
190 	l_gid16_t *linux_gidset;
191 	gid_t *bsd_gidset;
192 	int bsd_gidsetsz, ngrp, error;
193 
194 	cred = td->td_ucred;
195 	bsd_gidset = cred->cr_groups;
196 	bsd_gidsetsz = cred->cr_ngroups - 1;
197 
198 	/*
199 	 * cr_groups[0] holds egid. Returning the whole set
200 	 * here will cause a duplicate. Exclude cr_groups[0]
201 	 * to prevent that.
202 	 */
203 
204 	if ((ngrp = args->gidsetsize) == 0) {
205 		td->td_retval[0] = bsd_gidsetsz;
206 		return (0);
207 	}
208 
209 	if (ngrp < bsd_gidsetsz)
210 		return (EINVAL);
211 
212 	ngrp = 0;
213 	linux_gidset = malloc(bsd_gidsetsz * sizeof(*linux_gidset),
214 	    M_LINUX, M_WAITOK);
215 	while (ngrp < bsd_gidsetsz) {
216 		linux_gidset[ngrp] = bsd_gidset[ngrp + 1];
217 		ngrp++;
218 	}
219 
220 	error = copyout(linux_gidset, args->gidset, ngrp * sizeof(l_gid16_t));
221 	free(linux_gidset, M_LINUX);
222 	if (error) {
223 		LIN_SDT_PROBE1(uid16, linux_getgroups16, copyout_error, error);
224 		return (error);
225 	}
226 
227 	td->td_retval[0] = ngrp;
228 
229 	return (0);
230 }
231 
232 int
233 linux_getgid16(struct thread *td, struct linux_getgid16_args *args)
234 {
235 
236 	td->td_retval[0] = td->td_ucred->cr_rgid;
237 
238 	return (0);
239 }
240 
241 int
242 linux_getuid16(struct thread *td, struct linux_getuid16_args *args)
243 {
244 
245 	td->td_retval[0] = td->td_ucred->cr_ruid;
246 
247 	return (0);
248 }
249 
250 int
251 linux_getegid16(struct thread *td, struct linux_getegid16_args *args)
252 {
253 	struct getegid_args bsd;
254 	int error;
255 
256 	error = sys_getegid(td, &bsd);
257 
258 	return (error);
259 }
260 
261 int
262 linux_geteuid16(struct thread *td, struct linux_geteuid16_args *args)
263 {
264 	struct geteuid_args bsd;
265 	int error;
266 
267 	error = sys_geteuid(td, &bsd);
268 
269 	return (error);
270 }
271 
272 int
273 linux_setgid16(struct thread *td, struct linux_setgid16_args *args)
274 {
275 	struct setgid_args bsd;
276 	int error;
277 
278 	bsd.gid = args->gid;
279 	error = sys_setgid(td, &bsd);
280 
281 	return (error);
282 }
283 
284 int
285 linux_setuid16(struct thread *td, struct linux_setuid16_args *args)
286 {
287 	struct setuid_args bsd;
288 	int error;
289 
290 	bsd.uid = args->uid;
291 	error = sys_setuid(td, &bsd);
292 
293 	return (error);
294 }
295 
296 int
297 linux_setregid16(struct thread *td, struct linux_setregid16_args *args)
298 {
299 	struct setregid_args bsd;
300 	int error;
301 
302 	bsd.rgid = CAST_NOCHG(args->rgid);
303 	bsd.egid = CAST_NOCHG(args->egid);
304 	error = sys_setregid(td, &bsd);
305 
306 	return (error);
307 }
308 
309 int
310 linux_setreuid16(struct thread *td, struct linux_setreuid16_args *args)
311 {
312 	struct setreuid_args bsd;
313 	int error;
314 
315 	bsd.ruid = CAST_NOCHG(args->ruid);
316 	bsd.euid = CAST_NOCHG(args->euid);
317 	error = sys_setreuid(td, &bsd);
318 
319 	return (error);
320 }
321 
322 int
323 linux_setresgid16(struct thread *td, struct linux_setresgid16_args *args)
324 {
325 	struct setresgid_args bsd;
326 	int error;
327 
328 	bsd.rgid = CAST_NOCHG(args->rgid);
329 	bsd.egid = CAST_NOCHG(args->egid);
330 	bsd.sgid = CAST_NOCHG(args->sgid);
331 	error = sys_setresgid(td, &bsd);
332 
333 	return (error);
334 }
335 
336 int
337 linux_setresuid16(struct thread *td, struct linux_setresuid16_args *args)
338 {
339 	struct setresuid_args bsd;
340 	int error;
341 
342 	bsd.ruid = CAST_NOCHG(args->ruid);
343 	bsd.euid = CAST_NOCHG(args->euid);
344 	bsd.suid = CAST_NOCHG(args->suid);
345 	error = sys_setresuid(td, &bsd);
346 
347 	return (error);
348 }
349