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Unix/Linux 网络时间协议版本3 Network Time Protocol Version 3 (NTP) distribution for Unix systems

From [e-mail] Sun Jun 16 03:33:43 1996
X-NS-Transport-ID: 0000AA008EE70CC73566
Date: Sun, 26 May 1996 21:29:36 PDT
From: [e-mail]
Subject: Re:  bug in ntpq
In-Reply-to: "[e-mail]:edu:Xerox's message of Sun, 26 May 1996 19:51:17 PDT"
To: [e-mail]
cc: [e-mail]

See if you agree with this -- it returns a failure if either the variable name
length or the variable value length exceed their respective limits.

					\nick

*** ntpq/ntpq.c.orig	Fri Mar 29 08:46:12 1996
--- ntpq/ntpq.c	Sun May 26 21:21:10 1996
***************
*** 2411,2416 ****
--- 2411,2417 ----
  	register char *cp;
  	register char *np;
  	register char *cpend;
+ 	register char *npend;	/* character after last */
  	int quoted = 0;
  	static char name[MAXVARLEN];
  	static char value[MAXVALLEN];
***************
*** 2431,2439 ****
  	 * over any white space and terminate it.
  	 */
  	np = name;
! 	while (cp < cpend && *cp != ',' && *cp != '='
  	    && *cp != '\r' && *cp != '\n')
  		*np++ = *cp++;
  	while (isspace(*(np-1)))
  		np--;
  	*np = '\0';
--- 2432,2449 ----
  	 * over any white space and terminate it.
  	 */
  	np = name;
! 	npend = &name[MAXVARLEN];
! 	while (cp < cpend && np < npend && *cp != ',' && *cp != '='
  	    && *cp != '\r' && *cp != '\n')
  		*np++ = *cp++;
+ 	/*
+ 	 * Check if we ran out of name space, without reaching the end or a
+ 	 * terminating character
+ 	 */
+ 	if (np == npend && !(cp == cpend || *cp == ',' || *cp == '=' ||
+ 			     *cp == '\r' || *cp == '\n'))
+ 	  return 0;
+
  	while (isspace(*(np-1)))
  		np--;
  	*np = '\0';
***************
*** 2458,2468 ****
  	while (cp < cpend && (isspace(*cp) && *cp != '\r' && *cp != '\n'))
  		cp++;
  	np = value;
! 	while (cp < cpend && ((*cp != ',') || quoted))
  	  {
  	    quoted ^= ((*np++ = *cp++) == '"');
  	  }

  	while (np > value && isspace(*(np-1)))
  		np--;
  	*np = '\0';
--- 2468,2489 ----
  	while (cp < cpend && (isspace(*cp) && *cp != '\r' && *cp != '\n'))
  		cp++;
  	np = value;
! 	npend = &value[MAXVALLEN];
! 	while (cp < cpend && np < npend && ((*cp != ',') || quoted))
  	  {
  	    quoted ^= ((*np++ = *cp++) == '"');
  	  }

+ 	/*
+ 	 * Check if we overran the value buffer while still in a quoted string
+ 	 * or without finding a comma
+ 	 */
+ 	if (np == npend && (quoted || *cp != ','))
+ 	  return 0;
+
+ 	/*
+ 	 * Trim off any trailing whitespace
+ 	 */
  	while (np > value && isspace(*(np-1)))
  		np--;
  	*np = '\0';