xref: /freebsd/sys/compat/linux/linux_uid16.c (revision 640235e2c2ba32947f7c59d168437ffa1280f1e6)
1 /*-
2  * Copyright (c) 2001  The FreeBSD Project
3  * All rights reserved.
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 "opt_compat.h"
31 
32 #include <sys/fcntl.h>
33 #include <sys/param.h>
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/malloc.h>
37 #include <sys/mutex.h>
38 #include <sys/priv.h>
39 #include <sys/proc.h>
40 #include <sys/sdt.h>
41 #include <sys/syscallsubr.h>
42 #include <sys/sysproto.h>
43 #include <sys/systm.h>
44 
45 #ifdef COMPAT_LINUX32
46 #include <machine/../linux32/linux.h>
47 #include <machine/../linux32/linux32_proto.h>
48 #else
49 #include <machine/../linux/linux.h>
50 #include <machine/../linux/linux_proto.h>
51 #endif
52 
53 #include <compat/linux/linux_dtrace.h>
54 #include <compat/linux/linux_util.h>
55 
56 /* DTrace init */
57 LIN_SDT_PROVIDER_DECLARE(LINUX_DTRACE);
58 
59 /**
60  * DTrace probes in this module.
61  */
62 LIN_SDT_PROBE_DEFINE3(uid16, linux_chown16, entry, "char *", "l_uid16_t",
63     "l_gid16_t");
64 LIN_SDT_PROBE_DEFINE1(uid16, linux_chown16, conv_path, "char *");
65 LIN_SDT_PROBE_DEFINE1(uid16, linux_chown16, return, "int");
66 LIN_SDT_PROBE_DEFINE3(uid16, linux_lchown16, entry, "char *", "l_uid16_t",
67     "l_gid16_t");
68 LIN_SDT_PROBE_DEFINE1(uid16, linux_lchown16, conv_path, "char *");
69 LIN_SDT_PROBE_DEFINE1(uid16, linux_lchown16, return, "int");
70 LIN_SDT_PROBE_DEFINE2(uid16, linux_setgroups16, entry, "l_uint", "l_gid16_t *");
71 LIN_SDT_PROBE_DEFINE1(uid16, linux_setgroups16, copyin_error, "int");
72 LIN_SDT_PROBE_DEFINE1(uid16, linux_setgroups16, priv_check_cred_error, "int");
73 LIN_SDT_PROBE_DEFINE1(uid16, linux_setgroups16, return, "int");
74 LIN_SDT_PROBE_DEFINE2(uid16, linux_getgroups16, entry, "l_uint", "l_gid16_t *");
75 LIN_SDT_PROBE_DEFINE1(uid16, linux_getgroups16, copyout_error, "int");
76 LIN_SDT_PROBE_DEFINE1(uid16, linux_getgroups16, return, "int");
77 LIN_SDT_PROBE_DEFINE0(uid16, linux_getgid16, entry);
78 LIN_SDT_PROBE_DEFINE1(uid16, linux_getgid16, return, "int");
79 LIN_SDT_PROBE_DEFINE0(uid16, linux_getuid16, entry);
80 LIN_SDT_PROBE_DEFINE1(uid16, linux_getuid16, return, "int");
81 LIN_SDT_PROBE_DEFINE0(uid16, linux_getegid16, entry);
82 LIN_SDT_PROBE_DEFINE1(uid16, linux_getegid16, return, "int");
83 LIN_SDT_PROBE_DEFINE0(uid16, linux_geteuid16, entry);
84 LIN_SDT_PROBE_DEFINE1(uid16, linux_geteuid16, return, "int");
85 LIN_SDT_PROBE_DEFINE1(uid16, linux_setgid16, entry, "l_gid16_t");
86 LIN_SDT_PROBE_DEFINE1(uid16, linux_setgid16, return, "int");
87 LIN_SDT_PROBE_DEFINE1(uid16, linux_setuid16, entry, "l_uid16_t");
88 LIN_SDT_PROBE_DEFINE1(uid16, linux_setuid16, return, "int");
89 LIN_SDT_PROBE_DEFINE2(uid16, linux_setregid16, entry, "l_gid16_t", "l_gid16_t");
90 LIN_SDT_PROBE_DEFINE1(uid16, linux_setregid16, return, "int");
91 LIN_SDT_PROBE_DEFINE2(uid16, linux_setreuid16, entry, "l_uid16_t", "l_uid16_t");
92 LIN_SDT_PROBE_DEFINE1(uid16, linux_setreuid16, return, "int");
93 LIN_SDT_PROBE_DEFINE3(uid16, linux_setresgid16, entry, "l_gid16_t", "l_gid16_t",
94     "l_gid16_t");
95 LIN_SDT_PROBE_DEFINE1(uid16, linux_setresgid16, return, "int");
96 LIN_SDT_PROBE_DEFINE3(uid16, linux_setresuid16, entry, "l_uid16_t", "l_uid16_t",
97     "l_uid16_t");
98 LIN_SDT_PROBE_DEFINE1(uid16, linux_setresuid16, return, "int");
99 
100 DUMMY(setfsuid16);
101 DUMMY(setfsgid16);
102 DUMMY(getresuid16);
103 DUMMY(getresgid16);
104 
105 #define	CAST_NOCHG(x)	((x == 0xFFFF) ? -1 : x)
106 
107 int
108 linux_chown16(struct thread *td, struct linux_chown16_args *args)
109 {
110 	char *path;
111 	int error;
112 
113 	LCONVPATHEXIST(td, args->path, &path);
114 
115 	/*
116 	 * The DTrace probes have to be after the LCONVPATHEXIST, as
117 	 * LCONVPATHEXIST may return on its own and we do not want to
118 	 * have a stray entry without the corresponding return.
119 	 */
120 	LIN_SDT_PROBE3(uid16, linux_chown16, entry, args->path, args->uid,
121 	    args->gid);
122 	LIN_SDT_PROBE1(uid16, linux_chown16, conv_path, path);
123 
124 	error = kern_fchownat(td, AT_FDCWD, path, UIO_SYSSPACE,
125 	    CAST_NOCHG(args->uid), CAST_NOCHG(args->gid), 0);
126 	LFREEPATH(path);
127 
128 	LIN_SDT_PROBE1(uid16, linux_chown16, return, error);
129 	return (error);
130 }
131 
132 int
133 linux_lchown16(struct thread *td, struct linux_lchown16_args *args)
134 {
135 	char *path;
136 	int error;
137 
138 	LCONVPATHEXIST(td, args->path, &path);
139 
140 	/*
141 	 * The DTrace probes have to be after the LCONVPATHEXIST, as
142 	 * LCONVPATHEXIST may return on its own and we do not want to
143 	 * have a stray entry without the corresponding return.
144 	 */
145 	LIN_SDT_PROBE3(uid16, linux_lchown16, entry, args->path, args->uid,
146 	    args->gid);
147 	LIN_SDT_PROBE1(uid16, linux_lchown16, conv_path, path);
148 
149 	error = kern_fchownat(td, AT_FDCWD, path, UIO_SYSSPACE,
150 	    CAST_NOCHG(args->uid), CAST_NOCHG(args->gid), AT_SYMLINK_NOFOLLOW);
151 	LFREEPATH(path);
152 
153 	LIN_SDT_PROBE1(uid16, linux_lchown16, return, error);
154 	return (error);
155 }
156 
157 int
158 linux_setgroups16(struct thread *td, struct linux_setgroups16_args *args)
159 {
160 	struct ucred *newcred, *oldcred;
161 	l_gid16_t *linux_gidset;
162 	gid_t *bsd_gidset;
163 	int ngrp, error;
164 	struct proc *p;
165 
166 	LIN_SDT_PROBE2(uid16, linux_setgroups16, entry, args->gidsetsize,
167 	    args->gidset);
168 
169 	ngrp = args->gidsetsize;
170 	if (ngrp < 0 || ngrp >= ngroups_max + 1) {
171 		LIN_SDT_PROBE1(uid16, linux_setgroups16, return, EINVAL);
172 		return (EINVAL);
173 	}
174 	linux_gidset = malloc(ngrp * sizeof(*linux_gidset), M_LINUX, M_WAITOK);
175 	error = copyin(args->gidset, linux_gidset, ngrp * sizeof(l_gid16_t));
176 	if (error) {
177 		LIN_SDT_PROBE1(uid16, linux_setgroups16, copyin_error, error);
178 		LIN_SDT_PROBE1(uid16, linux_setgroups16, return, error);
179 		free(linux_gidset, M_LINUX);
180 		return (error);
181 	}
182 	newcred = crget();
183 	p = td->td_proc;
184 	PROC_LOCK(p);
185 	oldcred = crcopysafe(p, newcred);
186 
187 	/*
188 	 * cr_groups[0] holds egid. Setting the whole set from
189 	 * the supplied set will cause egid to be changed too.
190 	 * Keep cr_groups[0] unchanged to prevent that.
191 	 */
192 
193 	if ((error = priv_check_cred(oldcred, PRIV_CRED_SETGROUPS, 0)) != 0) {
194 		PROC_UNLOCK(p);
195 		crfree(newcred);
196 
197 		LIN_SDT_PROBE1(uid16, linux_setgroups16, priv_check_cred_error,
198 		    error);
199 		goto out;
200 	}
201 
202 	if (ngrp > 0) {
203 		newcred->cr_ngroups = ngrp + 1;
204 
205 		bsd_gidset = newcred->cr_groups;
206 		ngrp--;
207 		while (ngrp >= 0) {
208 			bsd_gidset[ngrp + 1] = linux_gidset[ngrp];
209 			ngrp--;
210 		}
211 	}
212 	else
213 		newcred->cr_ngroups = 1;
214 
215 	setsugid(td->td_proc);
216 	proc_set_cred(p, newcred);
217 	PROC_UNLOCK(p);
218 	crfree(oldcred);
219 	error = 0;
220 out:
221 	free(linux_gidset, M_LINUX);
222 
223 	LIN_SDT_PROBE1(uid16, linux_setgroups16, return, error);
224 	return (error);
225 }
226 
227 int
228 linux_getgroups16(struct thread *td, struct linux_getgroups16_args *args)
229 {
230 	struct ucred *cred;
231 	l_gid16_t *linux_gidset;
232 	gid_t *bsd_gidset;
233 	int bsd_gidsetsz, ngrp, error;
234 
235 	LIN_SDT_PROBE2(uid16, linux_getgroups16, entry, args->gidsetsize,
236 	    args->gidset);
237 
238 	cred = td->td_ucred;
239 	bsd_gidset = cred->cr_groups;
240 	bsd_gidsetsz = cred->cr_ngroups - 1;
241 
242 	/*
243 	 * cr_groups[0] holds egid. Returning the whole set
244 	 * here will cause a duplicate. Exclude cr_groups[0]
245 	 * to prevent that.
246 	 */
247 
248 	if ((ngrp = args->gidsetsize) == 0) {
249 		td->td_retval[0] = bsd_gidsetsz;
250 
251 		LIN_SDT_PROBE1(uid16, linux_getgroups16, return, 0);
252 		return (0);
253 	}
254 
255 	if (ngrp < bsd_gidsetsz) {
256 		LIN_SDT_PROBE1(uid16, linux_getgroups16, return, EINVAL);
257 		return (EINVAL);
258 	}
259 
260 	ngrp = 0;
261 	linux_gidset = malloc(bsd_gidsetsz * sizeof(*linux_gidset),
262 	    M_LINUX, M_WAITOK);
263 	while (ngrp < bsd_gidsetsz) {
264 		linux_gidset[ngrp] = bsd_gidset[ngrp + 1];
265 		ngrp++;
266 	}
267 
268 	error = copyout(linux_gidset, args->gidset, ngrp * sizeof(l_gid16_t));
269 	free(linux_gidset, M_LINUX);
270 	if (error) {
271 		LIN_SDT_PROBE1(uid16, linux_getgroups16, copyout_error, error);
272 		LIN_SDT_PROBE1(uid16, linux_getgroups16, return, error);
273 		return (error);
274 	}
275 
276 	td->td_retval[0] = ngrp;
277 
278 	LIN_SDT_PROBE1(uid16, linux_getgroups16, return, 0);
279 	return (0);
280 }
281 
282 /*
283  * The FreeBSD native getgid(2) and getuid(2) also modify td->td_retval[1]
284  * when COMPAT_43 is defined. This clobbers registers that are assumed to
285  * be preserved. The following lightweight syscalls fixes this. See also
286  * linux_getpid(2), linux_getgid(2) and linux_getuid(2) in linux_misc.c
287  *
288  * linux_getgid16() - MP SAFE
289  * linux_getuid16() - MP SAFE
290  */
291 
292 int
293 linux_getgid16(struct thread *td, struct linux_getgid16_args *args)
294 {
295 
296 	LIN_SDT_PROBE0(uid16, linux_getgid16, entry);
297 
298 	td->td_retval[0] = td->td_ucred->cr_rgid;
299 
300 	LIN_SDT_PROBE1(uid16, linux_getgid16, return, 0);
301 	return (0);
302 }
303 
304 int
305 linux_getuid16(struct thread *td, struct linux_getuid16_args *args)
306 {
307 
308 	LIN_SDT_PROBE0(uid16, linux_getuid16, entry);
309 
310 	td->td_retval[0] = td->td_ucred->cr_ruid;
311 
312 	LIN_SDT_PROBE1(uid16, linux_getuid16, return, 0);
313 	return (0);
314 }
315 
316 int
317 linux_getegid16(struct thread *td, struct linux_getegid16_args *args)
318 {
319 	struct getegid_args bsd;
320 	int error;
321 
322 	LIN_SDT_PROBE0(uid16, linux_getegid16, entry);
323 
324 	error = sys_getegid(td, &bsd);
325 
326 	LIN_SDT_PROBE1(uid16, linux_getegid16, return, error);
327 	return (error);
328 }
329 
330 int
331 linux_geteuid16(struct thread *td, struct linux_geteuid16_args *args)
332 {
333 	struct geteuid_args bsd;
334 	int error;
335 
336 	LIN_SDT_PROBE0(uid16, linux_geteuid16, entry);
337 
338 	error = sys_geteuid(td, &bsd);
339 
340 	LIN_SDT_PROBE1(uid16, linux_geteuid16, return, error);
341 	return (error);
342 }
343 
344 int
345 linux_setgid16(struct thread *td, struct linux_setgid16_args *args)
346 {
347 	struct setgid_args bsd;
348 	int error;
349 
350 	LIN_SDT_PROBE1(uid16, linux_setgid16, entry, args->gid);
351 
352 	bsd.gid = args->gid;
353 	error = sys_setgid(td, &bsd);
354 
355 	LIN_SDT_PROBE1(uid16, linux_setgid16, return, error);
356 	return (error);
357 }
358 
359 int
360 linux_setuid16(struct thread *td, struct linux_setuid16_args *args)
361 {
362 	struct setuid_args bsd;
363 	int error;
364 
365 	LIN_SDT_PROBE1(uid16, linux_setuid16, entry, args->uid);
366 
367 	bsd.uid = args->uid;
368 	error = sys_setuid(td, &bsd);
369 
370 	LIN_SDT_PROBE1(uid16, linux_setuid16, return, error);
371 	return (error);
372 }
373 
374 int
375 linux_setregid16(struct thread *td, struct linux_setregid16_args *args)
376 {
377 	struct setregid_args bsd;
378 	int error;
379 
380 	LIN_SDT_PROBE2(uid16, linux_setregid16, entry, args->rgid, args->egid);
381 
382 	bsd.rgid = CAST_NOCHG(args->rgid);
383 	bsd.egid = CAST_NOCHG(args->egid);
384 	error = sys_setregid(td, &bsd);
385 
386 	LIN_SDT_PROBE1(uid16, linux_setregid16, return, error);
387 	return (error);
388 }
389 
390 int
391 linux_setreuid16(struct thread *td, struct linux_setreuid16_args *args)
392 {
393 	struct setreuid_args bsd;
394 	int error;
395 
396 	LIN_SDT_PROBE2(uid16, linux_setreuid16, entry, args->ruid, args->euid);
397 
398 	bsd.ruid = CAST_NOCHG(args->ruid);
399 	bsd.euid = CAST_NOCHG(args->euid);
400 	error = sys_setreuid(td, &bsd);
401 
402 	LIN_SDT_PROBE1(uid16, linux_setreuid16, return, error);
403 	return (error);
404 }
405 
406 int
407 linux_setresgid16(struct thread *td, struct linux_setresgid16_args *args)
408 {
409 	struct setresgid_args bsd;
410 	int error;
411 
412 	LIN_SDT_PROBE3(uid16, linux_setresgid16, entry, args->rgid, args->egid,
413 	    args->sgid);
414 
415 	bsd.rgid = CAST_NOCHG(args->rgid);
416 	bsd.egid = CAST_NOCHG(args->egid);
417 	bsd.sgid = CAST_NOCHG(args->sgid);
418 	error = sys_setresgid(td, &bsd);
419 
420 	LIN_SDT_PROBE1(uid16, linux_setresgid16, return, error);
421 	return (error);
422 }
423 
424 int
425 linux_setresuid16(struct thread *td, struct linux_setresuid16_args *args)
426 {
427 	struct setresuid_args bsd;
428 	int error;
429 
430 	LIN_SDT_PROBE3(uid16, linux_setresuid16, entry, args->ruid, args->euid,
431 	    args->suid);
432 
433 	bsd.ruid = CAST_NOCHG(args->ruid);
434 	bsd.euid = CAST_NOCHG(args->euid);
435 	bsd.suid = CAST_NOCHG(args->suid);
436 	error = sys_setresuid(td, &bsd);
437 
438 	LIN_SDT_PROBE1(uid16, linux_setresuid16, return, error);
439 	return (error);
440 }
441