Description of problem:
When setting UID_MAX >= 2147483647 in login.defs useradd will segfault when adding new users.


Version-Release number of selected component (if applicable):
RHEL 6
shadow-utils-4.1.4.2-8.el6.x86_64


How reproducible:
Every time


Steps to Reproduce:
1. Edit login.defs to have UID_MAX >= 2147483647
   # sed -i 's/^UID_MAX.*$/UID_MAX                 2147483647/' login.defs
2. Add user
   # useradd test
   segfault
  
Actual results:
segfault

Expected results:
Error message or accept values of UID_MAX >= int

Additional info:

Starting program: /usr/sbin/useradd test

Program received signal SIGSEGV, Segmentation fault.
0x0000000000408484 in find_new_uid (sys_user=false, uid=0x6158c8, 
    preferred_uid=0x0) at /usr/include/bits/string3.h:86
warning: Source file is more recent than executable.
86	  return __builtin___memset_chk (__dest, __ch, __len, __bos0 (__dest));
(gdb) bt
#0  0x0000000000408484 in find_new_uid (sys_user=false, uid=0x6158c8, 
    preferred_uid=0x0) at /usr/include/bits/string3.h:86
#1  0x00000000004069be in main (argc=<value optimized out>, 
    argv=<value optimized out>) at useradd.c:1973

Here's the relevant section of code from useradd.c

1968		if (!oflg) {
1969			/* first, seek for a valid uid to use for this user.
1970			 * We do this because later we can use the uid we found as
1971			 * gid too ... --gafton */
1972			if (!uflg) {
1973				if (find_new_uid (rflg, &user_id, NULL) < 0) {
1974					fprintf (stderr, _("%s: can't create user\n"), Prog);
1975					fail_exit (E_UID_IN_USE);
1976				}
1977			} else {

If we look at find_new_uid.c:53
53	{
(gdb) list
48	 * Return 0 on success, -1 if no unused UIDs are available.
49	 */
50	int find_new_uid (bool sys_user,
51	                  uid_t *uid,
52	                  /*@null@*/uid_t const *preferred_uid)
53	{
54		const struct passwd *pwd;
55		uid_t uid_min, uid_max, user_id, id;
56		bool *used_uids;
57	
58		assert (uid != NULL);
59	
60		if (!sys_user) {
61			uid_min = (uid_t) getdef_ulong ("UID_MIN", 500UL);
62			uid_max = (uid_t) getdef_ulong ("UID_MAX", 60000UL);
63		} else {
64			uid_min = (uid_t) getdef_ulong ("SYS_UID_MIN", 201UL);
65			uid_max = (uid_t) getdef_ulong ("UID_MIN", 500UL) - 1;
66			uid_max = (uid_t) getdef_ulong ("SYS_UID_MAX", (unsigned long) uid_max);
67		}