Re: system/3640: installboot dumps core when given a non numeric argument to -s parameter

[Pedro Martelletto <pbastos@rdc.puc-rio.br>]

The following reply was made to PR system/3640; it has been noted by GNATS.

From: Pedro Martelletto <pbastos@rdc.puc-rio.br>
To: lsalle@taciturne.net
Cc: gnats@openbsd.org
Subject: Re: system/3640: installboot dumps core when given a non numeric argument to -s parameter
Date: Tue, 20 Jan 2004 10:12:40 -0200

 This is happening because an unchecked atoi() is returning 0, a value
 that later on the program uses to divide another number by, then causing
 the floating point exception. The best way to handle that would be using
 one of strtol/strtoul() and checking for {under,over}flows, but anyway,
 the attached diff should fix it...
 
 -p.
 
 On Tue, Jan 20, 2004 at 12:10:32PM +0100, lsalle@taciturne.net wrote:
 > >Number:         3640
 > >Category:       system
 > >Synopsis:       installboot dumps core when given a non numeric argument to -s parameter
 > >Confidential:   yes
 > >Severity:       non-critical
 > >Priority:       low
 > >Responsible:    bugs
 > >State:          open
 > >Quarter:        
 > >Keywords:       
 > >Date-Required:
 > >Class:          sw-bug
 > >Submitter-Id:   net
 > >Arrival-Date:   Tue Jan 20 11:20:02 GMT 2004
 > >Closed-Date:
 > >Last-Modified:
 > >Originator:     staff
 > >Release:        OPENBSD_3_4
 > >Organization:
 > net
 > 
 > In the following shell script, a non-numeric string follows the -s argument to installboot, resulting in a core dump (floating point exception).
 Index: installboot.c
 ===================================================================
 RCS file: /cvs/src/sys/arch/i386/stand/installboot/installboot.c,v
 retrieving revision 1.41
 diff -u -r1.41 installboot.c
 --- installboot.c	2003/08/25 23:27:43	1.41
 +++ installboot.c	2004/01/20 12:02:31
 @@ -114,10 +114,22 @@
  		switch (c) {
  		case 'h':
  			nheads = atoi(optarg);
 +			if (!nheads) {
 +				(void)fprintf(stderr,
 +				    "invalid argument to option -h\n");
 +				usage();
 +			}
 +
  			userspec = 1;
  			break;
  		case 's':
  			nsectors = atoi(optarg);
 +			if (!nsectors) {
 +				(void)fprintf(stderr,
 +				    "invalid argument to option -s\n");
 +				usage();
 +			}
 +
  			userspec = 1;
  			break;
  		case 'n':