xref: /freebsd/sys/compat/linux/linux_uid16.c (revision 038405f32f71ad8ba0280ae066417f986ede79db)
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 "opt_compat.h"
33 
34 #include <sys/fcntl.h>
35 #include <sys/param.h>
36 #include <sys/kernel.h>
37 #include <sys/lock.h>
38 #include <sys/malloc.h>
39 #include <sys/mutex.h>
40 #include <sys/priv.h>
41 #include <sys/proc.h>
42 #include <sys/sdt.h>
43 #include <sys/syscallsubr.h>
44 #include <sys/sysproto.h>
45 #include <sys/systm.h>
46 
47 #ifdef COMPAT_LINUX32
48 #include <machine/../linux32/linux.h>
49 #include <machine/../linux32/linux32_proto.h>
50 #else
51 #include <machine/../linux/linux.h>
52 #include <machine/../linux/linux_proto.h>
53 #endif
54 
55 #include <compat/linux/linux_dtrace.h>
56 #include <compat/linux/linux_util.h>
57 
58 /* DTrace init */
59 LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE);
60 
61 /**
62  * DTrace probes in this module.
63  */
64 LIN_SDT_PROBE_DEFINE1(uid16, linux_chown16, conv_path, "char *");
65 LIN_SDT_PROBE_DEFINE1(uid16, linux_lchown16, conv_path, "char *");
66 LIN_SDT_PROBE_DEFINE1(uid16, linux_setgroups16, copyin_error, "int");
67 LIN_SDT_PROBE_DEFINE1(uid16, linux_setgroups16, priv_check_cred_error, "int");
68 LIN_SDT_PROBE_DEFINE1(uid16, linux_getgroups16, copyout_error, "int");
69 
70 DUMMY(setfsuid16);
71 DUMMY(setfsgid16);
72 DUMMY(getresuid16);
73 DUMMY(getresgid16);
74 
75 #define	CAST_NOCHG(x)	((x == 0xFFFF) ? -1 : x)
76 
77 int
78 linux_chown16(struct thread *td, struct linux_chown16_args *args)
79 {
80 	char *path;
81 	int error;
82 
83 	if (!LUSECONVPATH(td) && !SDT_PROBES_ENABLED()) {
84 		error = kern_fchownat(td, AT_FDCWD, args->path, UIO_USERSPACE,
85 		    CAST_NOCHG(args->uid), CAST_NOCHG(args->gid), 0);
86 	} else {
87 		LCONVPATHEXIST(args->path, &path);
88 		/*
89 		 * The DTrace probes have to be after the LCONVPATHEXIST, as
90 		 * LCONVPATHEXIST may return on its own and we do not want to
91 		 * have a stray entry without the corresponding return.
92 		 */
93 		LIN_SDT_PROBE1(uid16, linux_chown16, conv_path, path);
94 
95 		error = kern_fchownat(td, AT_FDCWD, path, UIO_SYSSPACE,
96 		    CAST_NOCHG(args->uid), CAST_NOCHG(args->gid), 0);
97 		LFREEPATH(path);
98 	}
99 	return (error);
100 }
101 
102 int
103 linux_lchown16(struct thread *td, struct linux_lchown16_args *args)
104 {
105 	char *path;
106 	int error;
107 
108 	if (!LUSECONVPATH(td) && !SDT_PROBES_ENABLED()) {
109 		error = kern_fchownat(td, AT_FDCWD, args->path, UIO_USERSPACE,
110 		    CAST_NOCHG(args->uid), CAST_NOCHG(args->gid), AT_SYMLINK_NOFOLLOW);
111 	} else {
112 		LCONVPATHEXIST(args->path, &path);
113 
114 		/*
115 		 * The DTrace probes have to be after the LCONVPATHEXIST, as
116 		 * LCONVPATHEXIST may return on its own and we do not want to
117 		 * have a stray entry without the corresponding return.
118 		 */
119 		LIN_SDT_PROBE1(uid16, linux_lchown16, conv_path, path);
120 
121 		error = kern_fchownat(td, AT_FDCWD, path, UIO_SYSSPACE,
122 		    CAST_NOCHG(args->uid), CAST_NOCHG(args->gid), AT_SYMLINK_NOFOLLOW);
123 		LFREEPATH(path);
124 	}
125 	return (error);
126 }
127 
128 int
129 linux_setgroups16(struct thread *td, struct linux_setgroups16_args *args)
130 {
131 	struct ucred *newcred, *oldcred;
132 	l_gid16_t *linux_gidset;
133 	gid_t *bsd_gidset;
134 	int ngrp, error;
135 	struct proc *p;
136 
137 	ngrp = args->gidsetsize;
138 	if (ngrp < 0 || ngrp >= ngroups_max + 1)
139 		return (EINVAL);
140 	linux_gidset = malloc(ngrp * sizeof(*linux_gidset), M_LINUX, M_WAITOK);
141 	error = copyin(args->gidset, linux_gidset, ngrp * sizeof(l_gid16_t));
142 	if (error) {
143 		LIN_SDT_PROBE1(uid16, linux_setgroups16, copyin_error, error);
144 		free(linux_gidset, M_LINUX);
145 		return (error);
146 	}
147 	newcred = crget();
148 	p = td->td_proc;
149 	PROC_LOCK(p);
150 	oldcred = crcopysafe(p, newcred);
151 
152 	/*
153 	 * cr_groups[0] holds egid. Setting the whole set from
154 	 * the supplied set will cause egid to be changed too.
155 	 * Keep cr_groups[0] unchanged to prevent that.
156 	 */
157 
158 	if ((error = priv_check_cred(oldcred, PRIV_CRED_SETGROUPS)) != 0) {
159 		PROC_UNLOCK(p);
160 		crfree(newcred);
161 
162 		LIN_SDT_PROBE1(uid16, linux_setgroups16, priv_check_cred_error,
163 		    error);
164 		goto out;
165 	}
166 
167 	if (ngrp > 0) {
168 		newcred->cr_ngroups = ngrp + 1;
169 
170 		bsd_gidset = newcred->cr_groups;
171 		ngrp--;
172 		while (ngrp >= 0) {
173 			bsd_gidset[ngrp + 1] = linux_gidset[ngrp];
174 			ngrp--;
175 		}
176 	}
177 	else
178 		newcred->cr_ngroups = 1;
179 
180 	setsugid(td->td_proc);
181 	proc_set_cred(p, newcred);
182 	PROC_UNLOCK(p);
183 	crfree(oldcred);
184 	error = 0;
185 out:
186 	free(linux_gidset, M_LINUX);
187 
188 	return (error);
189 }
190 
191 int
192 linux_getgroups16(struct thread *td, struct linux_getgroups16_args *args)
193 {
194 	struct ucred *cred;
195 	l_gid16_t *linux_gidset;
196 	gid_t *bsd_gidset;
197 	int bsd_gidsetsz, ngrp, error;
198 
199 	cred = td->td_ucred;
200 	bsd_gidset = cred->cr_groups;
201 	bsd_gidsetsz = cred->cr_ngroups - 1;
202 
203 	/*
204 	 * cr_groups[0] holds egid. Returning the whole set
205 	 * here will cause a duplicate. Exclude cr_groups[0]
206 	 * to prevent that.
207 	 */
208 
209 	if ((ngrp = args->gidsetsize) == 0) {
210 		td->td_retval[0] = bsd_gidsetsz;
211 		return (0);
212 	}
213 
214 	if (ngrp < bsd_gidsetsz)
215 		return (EINVAL);
216 
217 	ngrp = 0;
218 	linux_gidset = malloc(bsd_gidsetsz * sizeof(*linux_gidset),
219 	    M_LINUX, M_WAITOK);
220 	while (ngrp < bsd_gidsetsz) {
221 		linux_gidset[ngrp] = bsd_gidset[ngrp + 1];
222 		ngrp++;
223 	}
224 
225 	error = copyout(linux_gidset, args->gidset, ngrp * sizeof(l_gid16_t));
226 	free(linux_gidset, M_LINUX);
227 	if (error) {
228 		LIN_SDT_PROBE1(uid16, linux_getgroups16, copyout_error, error);
229 		return (error);
230 	}
231 
232 	td->td_retval[0] = ngrp;
233 
234 	return (0);
235 }
236 
237 int
238 linux_getgid16(struct thread *td, struct linux_getgid16_args *args)
239 {
240 
241 	td->td_retval[0] = td->td_ucred->cr_rgid;
242 
243 	return (0);
244 }
245 
246 int
247 linux_getuid16(struct thread *td, struct linux_getuid16_args *args)
248 {
249 
250 	td->td_retval[0] = td->td_ucred->cr_ruid;
251 
252 	return (0);
253 }
254 
255 int
256 linux_getegid16(struct thread *td, struct linux_getegid16_args *args)
257 {
258 	struct getegid_args bsd;
259 	int error;
260 
261 	error = sys_getegid(td, &bsd);
262 
263 	return (error);
264 }
265 
266 int
267 linux_geteuid16(struct thread *td, struct linux_geteuid16_args *args)
268 {
269 	struct geteuid_args bsd;
270 	int error;
271 
272 	error = sys_geteuid(td, &bsd);
273 
274 	return (error);
275 }
276 
277 int
278 linux_setgid16(struct thread *td, struct linux_setgid16_args *args)
279 {
280 	struct setgid_args bsd;
281 	int error;
282 
283 	bsd.gid = args->gid;
284 	error = sys_setgid(td, &bsd);
285 
286 	return (error);
287 }
288 
289 int
290 linux_setuid16(struct thread *td, struct linux_setuid16_args *args)
291 {
292 	struct setuid_args bsd;
293 	int error;
294 
295 	bsd.uid = args->uid;
296 	error = sys_setuid(td, &bsd);
297 
298 	return (error);
299 }
300 
301 int
302 linux_setregid16(struct thread *td, struct linux_setregid16_args *args)
303 {
304 	struct setregid_args bsd;
305 	int error;
306 
307 	bsd.rgid = CAST_NOCHG(args->rgid);
308 	bsd.egid = CAST_NOCHG(args->egid);
309 	error = sys_setregid(td, &bsd);
310 
311 	return (error);
312 }
313 
314 int
315 linux_setreuid16(struct thread *td, struct linux_setreuid16_args *args)
316 {
317 	struct setreuid_args bsd;
318 	int error;
319 
320 	bsd.ruid = CAST_NOCHG(args->ruid);
321 	bsd.euid = CAST_NOCHG(args->euid);
322 	error = sys_setreuid(td, &bsd);
323 
324 	return (error);
325 }
326 
327 int
328 linux_setresgid16(struct thread *td, struct linux_setresgid16_args *args)
329 {
330 	struct setresgid_args bsd;
331 	int error;
332 
333 	bsd.rgid = CAST_NOCHG(args->rgid);
334 	bsd.egid = CAST_NOCHG(args->egid);
335 	bsd.sgid = CAST_NOCHG(args->sgid);
336 	error = sys_setresgid(td, &bsd);
337 
338 	return (error);
339 }
340 
341 int
342 linux_setresuid16(struct thread *td, struct linux_setresuid16_args *args)
343 {
344 	struct setresuid_args bsd;
345 	int error;
346 
347 	bsd.ruid = CAST_NOCHG(args->ruid);
348 	bsd.euid = CAST_NOCHG(args->euid);
349 	bsd.suid = CAST_NOCHG(args->suid);
350 	error = sys_setresuid(td, &bsd);
351 
352 	return (error);
353 }
354