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/*
* Check decoding of chown/chown32/lchown/lchown32/fchown/fchown32 syscalls.
*
* Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#ifdef UGID_TYPE_IS_SHORT
# define UGID_TYPE short
# define GETEUID syscall(__NR_geteuid)
# define GETEGID syscall(__NR_getegid)
# define CHECK_OVERFLOWUID(arg) check_overflowuid(arg)
# define CHECK_OVERFLOWGID(arg) check_overflowgid(arg)
#else
# define UGID_TYPE int
# define GETEUID geteuid()
# define GETEGID getegid()
# define CHECK_OVERFLOWUID(arg)
# define CHECK_OVERFLOWGID(arg)
#endif
#define UNLINK_SAMPLE \
do { \
if (unlink(sample)) \
perror_msg_and_fail("unlink"); \
} while (0)
#define CLOSE_SAMPLE \
do { \
if (close(fd)) \
perror_msg_and_fail("close"); \
} while (0)
#ifdef ACCESS_BY_DESCRIPTOR
# define SYSCALL_ARG1 fd
# define FMT_ARG1 "%d"
# define EOK_CMD CLOSE_SAMPLE
# define CLEANUP_CMD UNLINK_SAMPLE
#else
# define SYSCALL_ARG1 sample
# define FMT_ARG1 "\"%s\""
# define EOK_CMD UNLINK_SAMPLE
# define CLEANUP_CMD CLOSE_SAMPLE
#endif
static int
ugid2int(const unsigned UGID_TYPE id)
{
if ((unsigned UGID_TYPE) -1U == id)
return -1;
else
return id;
}
static void
print_int(const unsigned int num)
{
if (num == -1U)
printf(", -1");
else
printf(", %u", num);
}
static int
num_matches_id(const unsigned int num, const unsigned int id)
{
return num == id || num == -1U;
}
#define PAIR(val) { val, gid }, { uid, val }
int
main(void)
{
static const char sample[] = SYSCALL_NAME "_sample";
unsigned int uid = GETEUID;
CHECK_OVERFLOWUID(uid);
unsigned int gid = GETEGID;
CHECK_OVERFLOWUID(gid);
const struct {
const long uid, gid;
} tests[] = {
{ uid, gid },
{ (unsigned long) 0xffffffff00000000ULL | uid, gid },
{ uid, (unsigned long) 0xffffffff00000000ULL | gid },
PAIR(-1U),
PAIR(-1L),
{ 0xffff0000U | uid, gid },
{ uid, 0xffff0000U | gid },
PAIR(0xffff),
PAIR(0xc0deffffU),
PAIR(0xfacefeedU),
PAIR((long) 0xfacefeeddeadbeefULL)
};
int fd = open(sample, O_RDONLY | O_CREAT, 0400);
if (fd < 0)
perror_msg_and_fail("open");
CLEANUP_CMD;
unsigned int i;
long expected = 0;
for (i = 0; i < ARRAY_SIZE(tests); ++i) {
const unsigned int unum = ugid2int(tests[i].uid);
const unsigned int gnum = ugid2int(tests[i].gid);
if (num_matches_id(unum, uid) &&
num_matches_id(gnum, gid)) {
if (expected)
continue;
} else {
if (!expected) {
expected = -1;
EOK_CMD;
}
}
const long rc = syscall(SYSCALL_NR, SYSCALL_ARG1,
tests[i].uid, tests[i].gid);
const char *errstr = sprintrc(rc);
printf("%s(" FMT_ARG1, SYSCALL_NAME, SYSCALL_ARG1);
print_int(unum);
print_int(gnum);
printf(") = %s\n", errstr);
}
puts("+++ exited with 0 +++");
return 0;
}
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