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
|
/*
* Copyright (c) 2004, 2005 Darren Tucker (dtucker at zip com au).
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "../config.h"
#include <sys/types.h>
#include <errno.h>
#include <unistd.h>
int
setresuid(uid_t ruid, uid_t euid, uid_t suid)
{
uid_t ouid;
int ret = -1;
/* Allow only the tested configuration. */
if (ruid != euid || euid != suid) {
errno = ENOSYS;
return -1;
}
ouid = getuid();
if ((ret = setreuid(euid, euid)) == -1)
return -1;
/*
* When real, effective and saved uids are the same and we have
* changed uids, sanity check that we cannot restore the old uid.
*/
if (ruid == euid && euid == suid && ouid != ruid &&
setuid(ouid) != -1 && seteuid(ouid) != -1) {
errno = EINVAL;
return -1;
}
/*
* Finally, check that the real and effective uids are what we
* expect.
*/
if (getuid() != ruid || geteuid() != euid) {
errno = EACCES;
return -1;
}
return ret;
}
|
