From owner-freebsd-bugs@FreeBSD.ORG  Sat Jan 12 11:10:03 2008
Return-Path: <owner-freebsd-bugs@FreeBSD.ORG>
Delivered-To: freebsd-bugs@hub.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 8CEA816A417
	for <freebsd-bugs@hub.freebsd.org>;
	Sat, 12 Jan 2008 11:10:03 +0000 (UTC)
	(envelope-from gnats@FreeBSD.org)
Received: from freefall.freebsd.org (freefall.freebsd.org
	[IPv6:2001:4f8:fff6::28])
	by mx1.freebsd.org (Postfix) with ESMTP id 730E713C457
	for <freebsd-bugs@hub.freebsd.org>;
	Sat, 12 Jan 2008 11:10:03 +0000 (UTC)
	(envelope-from gnats@FreeBSD.org)
Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1])
	by freefall.freebsd.org (8.14.2/8.14.2) with ESMTP id m0CBA38j081392
	for <freebsd-bugs@freefall.freebsd.org>; Sat, 12 Jan 2008 11:10:03 GMT
	(envelope-from gnats@freefall.freebsd.org)
Received: (from gnats@localhost)
	by freefall.freebsd.org (8.14.2/8.14.1/Submit) id m0CBA3pD081385;
	Sat, 12 Jan 2008 11:10:03 GMT (envelope-from gnats)
Date: Sat, 12 Jan 2008 11:10:03 GMT
Message-Id: <200801121110.m0CBA3pD081385@freefall.freebsd.org>
To: freebsd-bugs@FreeBSD.org
From: Bruce Cran <bruce@cran.org.uk>
Cc: 
Subject: Re: bin/73337: nsswitch: potential invalid free
X-BeenThere: freebsd-bugs@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
Reply-To: Bruce Cran <bruce@cran.org.uk>
List-Id: Bug reports <freebsd-bugs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
	<mailto:freebsd-bugs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-bugs>
List-Post: <mailto:freebsd-bugs@freebsd.org>
List-Help: <mailto:freebsd-bugs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
	<mailto:freebsd-bugs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 12 Jan 2008 11:10:03 -0000

The following reply was made to PR bin/73337; it has been noted by GNATS.

From: Bruce Cran <bruce@cran.org.uk>
To: bug-followup@FreeBSD.org, nectar@FreeBSD.org
Cc:  
Subject: Re: bin/73337: nsswitch: potential invalid free
Date: Sat, 12 Jan 2008 11:01:48 +0000

 This still appears to be a problem on 7.0-PRERELEASE: single-threaded 
 applications get returned a statically-allocated [name]_state structure, 
 but all of the [name]_endstate functions such as dns_endstate assume 
 that the memory has been dynamically allocated - and so attempt to 
 free() a pointer which wasn't obtained through malloc().  I think the 
 patch below would fix the problem.
 
 --- nss_tls.h.old       2008-01-12 00:21:20.000000000 +0000
 +++ nss_tls.h   2008-01-12 10:54:17.000000000 +0000
 @@ -50,12 +50,18 @@
  static int                                                     \
  name##_getstate(struct name##_state **p)                       \
  {                                                              \
 -       static struct name##_state st;                          \
 +       static struct name##_state *st = NULL;                          \
         static pthread_once_t   keyinit = PTHREAD_ONCE_INIT;    \
         int                     rv;                             \
                                                                 \
         if (!__isthreaded || _pthread_main_np() != 0) {         \
 -               *p = &st;                                       \
 +               if (st == NULL) {               \
 +                       st = calloc(1, sizeof(*st));            \
 +                       if (st == NULL)         \
 +                               return (ENOMEM);    \
 +               }                           \
 +                                          \
 +               *p = st;                                        \
                 return (0);                                     \
         }                                                       \
         rv = _pthread_once(&keyinit, name##_keyinit);           \
 
 
 --
 Bruce Cran