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From: guy@sun.uucp (Guy Harris)
Newsgroups: net.bugs.usg
Subject: "xargs" dereferences null pointers
Message-ID: <2733@sun.uucp>
Date: Fri, 30-Aug-85 20:16:13 EDT
Article-I.D.: sun.2733
Posted: Fri Aug 30 20:16:13 1985
Date-Received: Sun, 1-Sep-85 06:02:22 EDT
Distribution: net
Organization: Sun Microsystems, Inc.
Lines: 43

It scans the argument list for flag arguments under the assumption that
the null pointer at the end of the argument list points to a string which
doesn't begin with a "-".  Sloppy, guys; a null pointer doesn't point to
*anything*, especially on a Sun...

*** /arch/s5r2/usr/src/cmd/xargs.c	Wed Jun 15 19:15:26 1983
--- ./xargs.c	Thu Aug 29 15:01:19 1985
***************
*** 55,61
  
  				/* look for flag arguments */
  
! while  ( (*argv)[0] == '-'  ) {
  	flagval = *argv+1;
  	switch ( *flagval++ ) {
  	case 'x': DASHX = LEGAL = TRUE;

--- 55,61 -----
  
  				/* look for flag arguments */
  
! while  ( argc != 0 && (*argv)[0] == '-'  ) {
  	flagval = *argv+1;
  	switch ( *flagval++ ) {
  	case 'x': DASHX = LEGAL = TRUE;
***************
*** 104,110
  		  break;
  	}
  	argv++;
! 	if ( --argc < 1 ) break;
  	}
  if( ! OK )
  	ERR = TRUE;

--- 104,110 -----
  		  break;
  	}
  	argv++;
! 	argc--;
  	}
  if( ! OK )
  	ERR = TRUE;