From: wietse@wzv.win.tue.nl (Wietse Venema)
Newsgroups: comp.security.misc,alt.security,comp.unix.admin,comp.sys.sun.admin
Subject: Re: new tcp wrappers and related stuff
Message-ID: <3569@svin02.info.win.tue.nl>
Date: 22 Jun 92 13:34:59 GMT
References: <3424@wzv.win.tue.nl>
Organization: Eindhoven University of Technology, The Netherlands

Mathew BM LIM (M.Lim@anu.edu.au) found a potential problem in my remote
user name lookup code (RFC 931). It may cause network daemons to die
with an alarm signal when user name lookup fails. The fix is simple:
just add an alarm(0) call (see below). A patch will be submitted to
comp.sources.misc and a fixed shar file will be made available for
anonymous ftp.

	Wietse

*** rfc931.c-	Fri Jun 12 10:41:44 1992
--- rfc931.c	Mon Jun 22 15:14:39 1992
***************
*** 80,85 ****
--- 80,86 ----
      if (connect(s, (struct sockaddr *) & sin, sizeof(sin)) == -1
  	|| (fp = fdopen(s, "w+")) == 0) {
  	close(s);
+ 	alarm(0);
  	return (result);
      }
      /* Query the RFC 931 server. Would 13-byte writes ever be broken up? */