>Number:         7273
>Category:       lib
>Synopsis:       core dump in initgroups()
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    lib-bug-people (Library Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 28 22:50:00 1999
>Last-Modified:
>Originator:     Giles Lean
>Organization:
>Release:        1.3.2, also -current source of 29th March 1999
>Environment:
	
System: NetBSD hpim2331 1.3.2 NetBSD 1.3.2 (KAYAK) #0: Wed Dec 23 04:11:55 PST 1998 giles@hpim2331:/usr/src/sys/arch/i386/compile/KAYAK i386


>Description:
	initgroups(3) calls warn() and warnx() on errors.

        (i)   this is undocumented
        (ii)  library functions shouldn't emit undocumented error
	      messages, but should leave error messages to the
              calling application
	(iii) depending on the status of stdio a core dump may result

>How-To-Repeat:
	Inspect code for initgroups.  Run the following program
	as a non root user, and see either:

 	"a: setgroups: Operation not permitted", or
	"Bus error (core dumped)"

#include <string.h>
#include <stdio.h>
#include <stddef.h>
#include <unistd.h>

int
main()
{
#ifdef COREDUMP
    memset(stderr, -1, sizeof(FILE));
#endif
    if (initgroups("root", 30) == -1)
	exit(1);
    else
	exit(0);
}
>Fix:
    Remove warn() and warnx() code, and just return -1 on error.

    The patch below does this.  There seems no good way to report
    an error from getgrouplist().

*** initgroups.c-orig	Mon Mar 29 16:45:15 1999
--- initgroups.c	Mon Mar 29 16:46:20 1999
***************
*** 62,73 ****
  	int ngroups;
  
  	ngroups = NGROUPS;
! 	if (getgrouplist(uname, agroup, groups, &ngroups) < 0)
! 		warnx("%s is in too many groups, using first %d",
! 		    uname, ngroups);
! 	if (setgroups(ngroups, groups) < 0) {
! 		warn("setgroups");
  		return (-1);
- 	}
  	return (0);
  }
--- 62,69 ----
  	int ngroups;
  
  	ngroups = NGROUPS;
! 	(void) getgrouplist(uname, agroup, groups, &ngroups);
! 	if (setgroups(ngroups, groups) < 0)
  		return (-1);
  	return (0);
  }
>Audit-Trail:
>Unformatted: