From owner-svn-src-head@freebsd.org Thu Sep 5 19:35:31 2019 Return-Path: Delivered-To: svn-src-head@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 198F8D15A5; Thu, 5 Sep 2019 19:35:31 +0000 (UTC) (envelope-from cy@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 46PWBB6hD3z4HMn; Thu, 5 Sep 2019 19:35:30 +0000 (UTC) (envelope-from cy@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id C9B7B91EE; Thu, 5 Sep 2019 19:35:30 +0000 (UTC) (envelope-from cy@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x85JZUMu000726; Thu, 5 Sep 2019 19:35:30 GMT (envelope-from cy@FreeBSD.org) Received: (from cy@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x85JZUbg000725; Thu, 5 Sep 2019 19:35:30 GMT (envelope-from cy@FreeBSD.org) Message-Id: <201909051935.x85JZUbg000725@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: cy set sender to cy@FreeBSD.org using -f From: Cy Schubert Date: Thu, 5 Sep 2019 19:35:30 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r351889 - head/lib/libc/nameser X-SVN-Group: head X-SVN-Commit-Author: cy X-SVN-Commit-Paths: head/lib/libc/nameser X-SVN-Commit-Revision: 351889 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 05 Sep 2019 19:35:31 -0000 Author: cy Date: Thu Sep 5 19:35:30 2019 New Revision: 351889 URL: https://svnweb.freebsd.org/changeset/base/351889 Log: Bounds check again after advancing cp, otherwise we have a possible heap buffer overflow. This was discovered by a Google fuzzer test. This can lead to remote denial of service. User interaction and execution privileges are not a prerequisite for exploitation. Reported by: enh at Google, to FreeBSD by maya@NetBSD.org Obtained from: enh at Google See also: NetBSD ns_name.c r1.12 Reviewed by: delphij, ume MFC after: 3 days https://android-review.googlesource.com/c/platform/bionic/+/1093130 Differential Revision: https://reviews.freebsd.org/D21523 Modified: head/lib/libc/nameser/ns_name.c Modified: head/lib/libc/nameser/ns_name.c ============================================================================== --- head/lib/libc/nameser/ns_name.c Thu Sep 5 19:25:44 2019 (r351888) +++ head/lib/libc/nameser/ns_name.c Thu Sep 5 19:35:30 2019 (r351889) @@ -684,7 +684,7 @@ ns_name_skip(const u_char **ptrptr, const u_char *eom) { const u_char *cp; u_int n; - int l; + int l = 0; cp = *ptrptr; while (cp < eom && (n = *cp++) != 0) { @@ -694,7 +694,7 @@ ns_name_skip(const u_char **ptrptr, const u_char *eom) cp += n; continue; case NS_TYPE_ELT: /*%< EDNS0 extended label */ - if ((l = labellen(cp - 1)) < 0) { + if (cp < eom && (l = labellen(cp - 1)) < 0) { errno = EMSGSIZE; /*%< XXX */ return (-1); }