Date: Tue, 5 Sep 1995 17:40:38 PDT From: Bill Fenner <fenner@parc.xerox.com> To: bugs@freebsd.org Subject: NIS passwd file doesn't work on 2.1.0-950726-SNAP? Message-ID: <95Sep5.174045pdt.177475@crevenia.parc.xerox.com>
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The root disk on the FreeBSD machine on my disk toasted itself, so I decided
to install 2.1.0-950726-SNAP. I couldn't get it to use our YP passwd file;
"login" refuses my login and "finger" dumps core.
The core dump is in _netyppass, in getpwent.c:742 -- free(result).
At this point, result == 0x72, and resultlen == 1702065519.
It turns out that our NIS map has a user that looks like
parcprotouser:*:100:0::/:/no_shell
and trying to sprintf() parcprotouser into user[UT_NAMESIZE] fails miserably.
I fixed it by
a) making user[] big enough to sprintf() into (tsk, tsk!)
b) truncating the username to UT_NAMESIZE bytes.
Note that this code also had a potential core dump if it got an answer from
the YP server that didn't have a colon in it. I didn't really know how
to handle that case; I truncated the username to 0 bytes, which isn't the
right thing to do, but I don't know what is.
Bill
--- /usr/src/lib/libc/gen/getpwent.c.orig Tue Sep 5 17:04:47 1995
+++ getpwent.c Tue Sep 5 17:32:14 1995
@@ -585,14 +585,15 @@
static int
_getyppass(struct passwd *pw, const char *name, const char *map)
{
- char *result, *s;
+ char *result, *s, *q;
static char resultbuf[1024];
int resultlen;
char mastermap[1024];
int gotmaster = 0;
struct _pw_cache *m, *p;
struct _namelist *n;
- char user[UT_NAMESIZE];
+ char user[UT_NAMESIZE + 1];
+ int ul;
if(!_pw_yp_domain) {
if(yp_get_default_domain(&_pw_yp_domain))
@@ -617,7 +618,13 @@
if(resultlen >= sizeof resultbuf) return 0;
strcpy(resultbuf, result);
- sprintf (user, "%.*s", (strchr(result, ':') - result), result);
+ q = strchr(result, ':');
+ if (q) {
+ ul = q - result > UT_NAMESIZE ? UT_NAMESIZE : q - result;
+ } else {
+ ul = 0; /*XXX no colon -- do what? */
+ }
+ sprintf (user, "%.*s", ul, result);
_pw_passwd.pw_fields = -1; /* Impossible value */
if (_minuscnt && _minushead) {
m = _minushead;
@@ -669,7 +676,9 @@
int gotmaster = 0;
struct _pw_cache *m, *p;
struct _namelist *n;
- char user[UT_NAMESIZE];
+ char user[UT_NAMESIZE+1];
+ int ul;
+ char *q;
if(!_pw_yp_domain) {
if(yp_get_default_domain(&_pw_yp_domain))
@@ -710,7 +719,13 @@
}
strcpy(resultbuf, result);
- sprintf(user, "%.*s", (strchr(result, ':') - result), result);
+ q = strchr(result, ':');
+ if (q) {
+ ul = q - result > UT_NAMESIZE ? UT_NAMESIZE : q - result;
+ } else {
+ ul = 0; /*XXX no colon -- do what? */
+ }
+ sprintf (user, "%.*s", ul, result);
_pw_passwd.pw_fields = -1; /* Impossible value */
if (_minuscnt && _minushead) {
m = _minushead;
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