Files
2023-01-04 16:03:35 -06:00

236 lines
7.0 KiB
C

/*
* Copyright (c) 1999 - 2004 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <config.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "roken.h"
#include "getauxval.h"
static void
check_secure_getenv(char **env)
{
size_t i;
char *v, *p;
for (i = 0; env[i] != NULL; i++) {
if ((v = strdup(env[i])) == NULL)
err(1, "could not allocate copy of %s", env[i]);
if ((p = strchr(v, '='))) {
*p = '\0';
if (issuid() && rk_secure_getenv(v) != NULL)
err(1, "rk_secure_getenv() returned non-NULL when issuid()!");
if (!issuid() && rk_secure_getenv(v) == NULL)
err(1, "rk_secure_getenv() returned NULL when !issuid()");
}
free(v);
}
}
static void
inject_suid(int suid)
{
#if defined(AT_SECURE) || (defined(AT_EUID) && defined(AT_RUID) && defined(AT_EGID) && defined(AT_RGID))
auxv_t e;
#ifdef AT_SECURE
unsigned long secure = suid ? 1 : 0;
#endif
#if defined(AT_EUID) && defined(AT_RUID) && defined(AT_EGID) && defined(AT_RGID)
unsigned long eid = suid ? 0 : 1000;
/* Inject real UID and GID */
e.a_un.a_val = 1000;
e.a_type = AT_UID;
if ((errno = rk_injectauxv(&e)) != 0)
err(1, "rk_injectauxv(AT_RUID) failed");
e.a_type = AT_GID;
if ((errno = rk_injectauxv(&e)) != 0)
err(1, "rk_injectauxv(AT_RGID) failed");
/* Inject effective UID and GID */
e.a_un.a_val = eid;
e.a_type = AT_EUID;
if ((errno = rk_injectauxv(&e)) != 0)
err(1, "rk_injectauxv(AT_EUID) failed");
e.a_type = AT_EGID;
if ((errno = rk_injectauxv(&e)) != 0)
err(1, "rk_injectauxv(AT_RGID) failed");
#endif
#ifdef AT_SECURE
e.a_un.a_val = secure;
e.a_type = AT_SECURE;
if ((errno = rk_injectauxv(&e)) != 0)
err(1, "rk_injectauxv(AT_SECURE) failed");
#endif
return;
#else
warnx("No ELF auxv types to inject");
#endif
}
static
unsigned long
getprocauxval(unsigned long type)
{
const auxv_t *e;
if ((e = rk_getauxv(type)) == NULL) {
errno = ENOENT;
return 0;
}
return e->a_un.a_val;
}
/* returns 1 if auxval type is handled specially by libc */
static int
is_special_auxv_p(long type)
{
#ifdef AT_HWCAP
if (type == AT_HWCAP)
return 1;
#endif
#ifdef AT_HWCAP2
if (type == AT_HWCAP2)
return 1;
#endif
return 0;
}
int
main(int argc, char **argv, char **env)
{
unsigned long max_t = 0;
unsigned long a[2];
unsigned long v;
ssize_t bytes;
int am_suid = issuid();
int fd;
(void) argc;
(void) argv;
if (getuid() == geteuid() && getgid() == getegid()) {
if (issuid())
errx(1, "issuid() false positive? Check AT_SECURE?");
} else {
if (!issuid())
errx(1, "issuid() did not detect set-uid-ness!");
}
if ((fd = open("/proc/self/auxv", O_RDONLY)) == -1)
return 0;
/*
* Check that for every ELF auxv entry in /proc/self/auxv we
* find the correct answer from the rk_get*auxval() functions.
*/
do {
bytes = read(fd, a, sizeof(a));
if (bytes != sizeof(a)) {
if (bytes == -1)
err(1, "Error reading from /proc/self/auxv");
if (bytes == 0)
warnx("Did not see terminator in /proc/self/auxv");
else
warnx("Partial entry in /proc/self/auxv or test interrupted");
(void) close(fd);
return 1;
}
if (a[0] > max_t)
max_t = a[0];
if (a[0] == 0) {
if (a[1] != 0)
warnx("AT_NULL with non-zero value %lu?!", a[1]);
continue;
} else if (is_special_auxv_p(a[0]))
continue;
errno = EACCES;
if ((v = rk_getauxval(a[0])) != a[1])
errx(1, "rk_getauxval(%lu) should have been %lu, was %lu",
a[0], a[1], v);
if (errno != EACCES)
errx(1, "rk_getauxval(%lu) did not preserve errno", a[0]);
if ((v = getprocauxval(a[0])) != a[1])
errx(1, "rk_getauxval(%lu) should have been %lu, was %lu",
a[0], a[1], v);
if (errno != EACCES)
errx(1, "rk_getauxv(%lu) did not preserve errno", a[0]);
printf("auxv type %lu -> %lu\n", a[0], a[1]);
} while (a[0] != 0 || a[1] != 0);
(void) close(fd);
if (max_t == 0) {
warnx("No entries in /proc/self/auxv or it is not available on this "
"system or this program is linked statically; cannot test "
"rk_getauxval()");
return 0;
}
errno = EACCES;
if ((v = rk_getauxval(max_t + 1)) != 0)
errx(1, "rk_getauxval((max_type_seen = %lu) + 1) should have been "
"0, was %lu", max_t, v);
if (errno != ENOENT)
errx(1, "rk_getauxval((max_type_seen = %lu) + 1) did not set "
"errno = ENOENT!", max_t);
errno = EACCES;
if ((v = getprocauxval(max_t + 1)) != 0)
errx(1, "rk_getauxv((max_type_seen = %lu) + 1) should have been "
"0, was %lu", max_t, v);
if (errno != ENOENT)
errx(1, "rk_getauxv((max_type_seen = %lu) + 1) did not set "
"errno = ENOENT!", max_t);
check_secure_getenv(env);
inject_suid(!am_suid);
if ((am_suid && issuid()) || (!am_suid && !issuid()))
errx(1, "rk_injectprocauxv() failed");
check_secure_getenv(env);
return 0;
}