1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
|
/*
Unix SMB/Netbios implementation.
Version 2.0
Copyright (C) Jeremy Allison 1998.
rewritten for version 2.0.6 by Tridge
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef AUTOCONF_TEST
#include "includes.h"
extern int DEBUGLEVEL;
#else
/* we are running this code in autoconf test mode to see which type of setuid
function works */
#if defined(HAVE_UNISTD_H)
#include <unistd.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <errno.h>
#ifdef HAVE_SYS_PRIV_H
#include <sys/priv.h>
#endif
#ifdef HAVE_SYS_ID_H
#include <sys/id.h>
#endif
#define DEBUG(x, y) printf y
#define smb_panic(x) exit(1)
#endif
/****************************************************************************
abort if we haven't set the uid correctly
****************************************************************************/
static void assert_uid(uid_t ruid, uid_t euid)
{
if ((euid != (uid_t)-1 && geteuid() != euid) ||
(ruid != (uid_t)-1 && getuid() != ruid)) {
#ifndef SMB_REGRESSION_TEST
DEBUG(0,("Failed to set uid privileges to (%d,%d) now set to (%d,%d)\n",
(int)ruid, (int)euid,
(int)getuid(), (int)geteuid()));
smb_panic("failed to set uid\n");
exit(1);
#endif
}
}
/****************************************************************************
abort if we haven't set the gid correctly
****************************************************************************/
static void assert_gid(gid_t rgid, gid_t egid)
{
if ((egid != (gid_t)-1 && getegid() != egid) ||
(rgid != (gid_t)-1 && getgid() != rgid)) {
#ifndef SMB_REGRESSION_TEST
DEBUG(0,("Failed to set gid privileges to (%d,%d) now set to (%d,%d) uid=(%d,%d)\n",
(int)rgid, (int)egid,
(int)getgid(), (int)getegid(),
(int)getuid(), (int)geteuid()));
smb_panic("failed to set gid\n");
exit(1);
#endif
}
}
/****************************************************************************
Gain root privilege before doing something.
We want to end up with ruid==euid==0
****************************************************************************/
void gain_root_privilege(void)
{
#if USE_SETRESUID
setresuid(0,0,0);
#endif
#if USE_SETEUID
seteuid(0);
#endif
#if USE_SETREUID
setreuid(0, 0);
#endif
#if USE_SETUIDX
setuidx(ID_EFFECTIVE, 0);
setuidx(ID_REAL, 0);
#endif
/* this is needed on some systems */
setuid(0);
assert_uid(0, 0);
}
/****************************************************************************
Ensure our real and effective groups are zero.
we want to end up with rgid==egid==0
****************************************************************************/
void gain_root_group_privilege(void)
{
#if USE_SETRESUID
setresgid(0,0,0);
#endif
#if USE_SETREUID
setregid(0,0);
#endif
#if USE_SETEUID
setegid(0);
#endif
#if USE_SETUIDX
setgidx(ID_EFFECTIVE, 0);
setgidx(ID_REAL, 0);
#endif
setgid(0);
assert_gid(0, 0);
}
/****************************************************************************
Set *only* the effective uid.
we want to end up with ruid==0 and euid==uid
****************************************************************************/
void set_effective_uid(uid_t uid)
{
#if USE_SETRESUID
setresuid(-1,uid,-1);
#endif
#if USE_SETREUID
setreuid(-1,uid);
#endif
#if USE_SETEUID
seteuid(uid);
#endif
#if USE_SETUIDX
setuidx(ID_EFFECTIVE, uid);
#endif
assert_uid(-1, uid);
}
/****************************************************************************
Set *only* the effective gid.
we want to end up with rgid==0 and egid==gid
****************************************************************************/
void set_effective_gid(gid_t gid)
{
#if USE_SETRESUID
setresgid(-1,gid,-1);
#endif
#if USE_SETREUID
setregid(-1,gid);
#endif
#if USE_SETEUID
setegid(gid);
#endif
#if USE_SETUIDX
setgidx(ID_EFFECTIVE, gid);
#endif
assert_gid(-1, gid);
}
static uid_t saved_euid, saved_ruid;
/****************************************************************************
save the real and effective uid for later restoration. Used by the quotas
code
****************************************************************************/
void save_re_uid(void)
{
saved_ruid = getuid();
saved_euid = geteuid();
}
/****************************************************************************
and restore them!
****************************************************************************/
void restore_re_uid(void)
{
set_effective_uid(0);
#if USE_SETRESUID
setresuid(saved_ruid, saved_euid, -1);
#elif USE_SETREUID
setreuid(saved_ruid, -1);
setreuid(-1,saved_euid);
#elif USE_SETUIDX
setuidx(ID_REAL, saved_ruid);
setuidx(ID_EFFECTIVE, saved_euid);
#else
set_effective_uid(saved_euid);
if (getuid() != saved_ruid)
setuid(saved_ruid);
set_effective_uid(saved_euid);
#endif
assert_uid(saved_ruid, saved_euid);
}
/****************************************************************************
set the real AND effective uid to the current effective uid in a way that
allows root to be regained.
This is only possible on some platforms.
****************************************************************************/
int set_re_uid(void)
{
uid_t uid = geteuid();
#if USE_SETRESUID
setresuid(geteuid(), -1, -1);
#endif
#if USE_SETREUID
setreuid(0, 0);
setreuid(uid, -1);
setreuid(-1, uid);
#endif
#if USE_SETEUID
/* can't be done */
return -1;
#endif
#if USE_SETUIDX
/* can't be done */
return -1;
#endif
assert_uid(uid, uid);
return 0;
}
/****************************************************************************
Become the specified uid and gid - permanently !
there should be no way back if possible
****************************************************************************/
void become_user_permanently(uid_t uid, gid_t gid)
{
/*
* First - gain root privilege. We do this to ensure
* we can lose it again.
*/
gain_root_privilege();
gain_root_group_privilege();
#if USE_SETRESUID
setresgid(gid,gid,gid);
setgid(gid);
setresuid(uid,uid,uid);
setuid(uid);
#endif
#if USE_SETREUID
setregid(gid,gid);
setgid(gid);
setreuid(uid,uid);
setuid(uid);
#endif
#if USE_SETEUID
setegid(gid);
setgid(gid);
setuid(uid);
seteuid(uid);
setuid(uid);
#endif
#if USE_SETUIDX
setgidx(ID_REAL, gid);
setgidx(ID_EFFECTIVE, gid);
setgid(gid);
setuidx(ID_REAL, uid);
setuidx(ID_EFFECTIVE, uid);
setuid(uid);
#endif
assert_uid(uid, uid);
assert_gid(gid, gid);
}
#ifdef AUTOCONF_TEST
/****************************************************************************
this function just checks that we don't get ENOSYS back
****************************************************************************/
static int have_syscall(void)
{
errno = 0;
#if USE_SETRESUID
setresuid(-1,-1,-1);
#endif
#if USE_SETREUID
setreuid(-1,-1);
#endif
#if USE_SETEUID
seteuid(-1);
#endif
#if USE_SETUIDX
setuidx(ID_EFFECTIVE, -1);
#endif
if (errno == ENOSYS) return -1;
return 0;
}
main()
{
if (getuid() != 0) {
#if (defined(AIX) && defined(USE_SETREUID))
/* setreuid is badly broken on AIX 4.1, we avoid it completely */
fprintf(stderr,"avoiding possibly broken setreuid\n");
exit(1);
#endif
/* if not running as root then at least check to see if we get ENOSYS - this
handles Linux 2.0.x with glibc 2.1 */
fprintf(stderr,"not running as root: checking for ENOSYS\n");
exit(have_syscall());
}
gain_root_privilege();
gain_root_group_privilege();
set_effective_gid(1);
set_effective_uid(1);
save_re_uid();
restore_re_uid();
gain_root_privilege();
gain_root_group_privilege();
become_user_permanently(1, 1);
setuid(0);
if (getuid() == 0) {
fprintf(stderr,"uid not set permanently\n");
exit(1);
}
printf("OK\n");
exit(0);
}
#endif
|
