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User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0)

Description of problem:
When add a huge number of user to one group member, the /etc/group file 
crashed. And if the gshadow is enabled, add a huge group members 
with /usr/sbin/useradd will lead to core dump.

How reproducible:
Always

Steps to Reproduce:
1.add a new group 'test'
2. Try following shell script
#!/bin/sh

let num=1
while let 'num<=5000'
do
echo 'Add user test'$num
/usr/sbin/useradd -G test test$num -m -k /dev/null -d /var/tmp/home
let num=$num+1
done


Actual Results:  a broken /etc/group file

Additional info:

I check the shadow-19990827-hugegroups.patch in the SRPM, and find the 
problem, the patch make a mistake in use of fgets(), here is my patch 
which will work with huge group members:
shadow-19990827-hugegroups.patch
// Cut here /////////////////////////////////
--- shadow-19990827/lib/commonio.c.broken	Tue Jul 18 19:58:09 2000
+++ shadow-19990827/lib/commonio.c	Tue Jul 18 20:02:54 2000
@@ -381,13 +381,17 @@
 int
 commonio_open(struct commonio_db *db, int mode)
 {
-	char	buf[8192];
+	char	*buf;
+	char	*tmpbuf;
+	unsigned long buflen=8192;
 	char	*cp;
 	char *line;
 	struct commonio_entry *p;
 	void *entry;
 	int flags = mode;

+	buf=(char *) malloc(buflen);
+
 	mode &= ~O_CREAT;

 	if (db->isopen || (mode != O_RDONLY && mode != O_RDWR)) {
@@ -417,7 +420,15 @@
 		return 0;
 	}

-	while (db->ops->fgets(buf, sizeof buf, db->fp)) {
+	while (db->ops->fgets(buf, buflen, db->fp)) {
+		while(!(cp = strrchr(buf, '\n')) && !feof(db->fp)) {
+			buflen += 8192;
+			tmpbuf=(char *)realloc(buf, buflen);
+			if (tmpbuf == NULL)
+				goto cleanup;
+			buf = tmpbuf;
+			db->ops->fgets(buf+buflen-8192-1, 8192+1, db-
>fp);
+		}
 		if ((cp = strrchr(buf, '\n')))
 			*cp = '\0';

@@ -444,6 +452,7 @@
 	}

 	db->isopen = 1;
+	free(buf);
 	return 1;

 cleanup_entry:
@@ -456,6 +465,7 @@
 	fclose(db->fp);
 	db->fp = NULL;
 	errno = ENOMEM;
+	free(buf);
 	return 0;
 }



--- shadow-19990827/lib/gshadow.c.broken	Thu May 17 11:38:05 2001
+++ shadow-19990827/lib/gshadow.c	Thu May 17 11:38:45 2001
@@ -48,7 +48,7 @@
 static	int	dbmerror;
 #endif
 
-#define	MAXMEM	1024
+#define	MAXMEM	10240
 
 static	FILE	*shadow;
 static	char	sgrbuf[BUFSIZ*4];


--- shadow-19990827/lib/defines.h.broken	Thu May 17 14:23:18 2001
+++ shadow-19990827/lib/defines.h	Thu May 17 14:24:50 2001
@@ -120,12 +120,16 @@
 #include <shadow.h>
 #if defined(SHADOWGRP) && !defined(GSHADOW)
 #include "gshadow_.h"
+#else
+#include <stdio.h>
 #endif
 #else  /* not HAVE_SHADOW_H */
 #include "shadow_.h"
 #ifdef SHADOWGRP
 #include "gshadow_.h"
+# else
+#include <stdio.h>
 #endif
 #endif  /* not HAVE_SHADOW_H */
 #endif  /* SHADOWPWD */
// Cut here ///////////////// 

shadow group must be disable in SPEC file to support huge group members, 
or you must change the MAXMEM in lib/gshadow.c to support number of 
members upto that value.