From owner-svn-src-all@FreeBSD.ORG Tue Aug 12 13:09:33 2014 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 0A2B3B12 for ; Tue, 12 Aug 2014 13:09:33 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id D56942C63 for ; Tue, 12 Aug 2014 13:09:32 +0000 (UTC) Received: from ume (uid 812) (envelope-from ume@FreeBSD.org) id 6165 by svn.freebsd.org (DragonFly Mail Agent v0.9+); Tue, 12 Aug 2014 13:09:32 +0000 From: Hajimu UMEMOTO Date: Tue, 12 Aug 2014 13:09:32 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r269873 - head/lib/libc/nameser X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Message-Id: <53ea120c.6165.1de1e179@svn.freebsd.org> X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 Aug 2014 13:09:33 -0000 Author: ume Date: Tue Aug 12 13:09:32 2014 New Revision: 269873 URL: http://svnweb.freebsd.org/changeset/base/269873 Log: Fix broken pointer overflow check ns_name_unpack() Many compilers may optimize away the overflow check `msg + l < msg', where `msg' is a pointer and `l' is an integer, because pointer overflow is undefined behavior in C. Use a safe precondition test `l >= eom - msg' instead. Reference: https://android-review.googlesource.com/#/c/50570/ Requested by: pfg Obtained from: NetBSD (CVS rev. 1.10) Modified: head/lib/libc/nameser/ns_name.c Directory Properties: head/lib/libc/ (props changed) Modified: head/lib/libc/nameser/ns_name.c ============================================================================== --- head/lib/libc/nameser/ns_name.c Tue Aug 12 12:45:30 2014 (r269872) +++ head/lib/libc/nameser/ns_name.c Tue Aug 12 13:09:32 2014 (r269873) @@ -463,11 +463,12 @@ ns_name_unpack2(const u_char *msg, const } if (len < 0) len = srcp - src + 1; - srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff)); - if (srcp < msg || srcp >= eom) { /*%< Out of range. */ + l = ((n & 0x3f) << 8) | (*srcp & 0xff); + if (l >= eom - msg) { /*%< Out of range. */ errno = EMSGSIZE; return (-1); } + srcp = msg + l; checked += 2; /* * Check for loops in the compressed name;