From patchwork Sun Jul 24 15:30:17 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Pitre X-Patchwork-Id: 9244911 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 53A70607FD for ; Sun, 24 Jul 2016 15:30:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3B51F2621E for ; Sun, 24 Jul 2016 15:30:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2FDDF26538; Sun, 24 Jul 2016 15:30:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EAEB02621E for ; Sun, 24 Jul 2016 15:30:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752036AbcGXPaj (ORCPT ); Sun, 24 Jul 2016 11:30:39 -0400 Received: from alt32.smtp-out.videotron.ca ([24.53.0.21]:30012 "EHLO alt32.smtp-out.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751340AbcGXPai (ORCPT ); Sun, 24 Jul 2016 11:30:38 -0400 Received: from yoda.home ([96.23.157.65]) by Videotron with SMTP id RLMRbeEZ5YOXTRLMSbJ3GY; Sun, 24 Jul 2016 11:30:37 -0400 X-Authority-Analysis: v=2.1 cv=Gfm35VjL c=1 sm=1 tr=0 a=keA3yYpnlypCNW5BNWqu+w==:117 a=keA3yYpnlypCNW5BNWqu+w==:17 a=L9H7d07YOLsA:10 a=9cW_t1CCXrUA:10 a=s5jvgZ67dGcA:10 a=cAmyUtKerLwA:10 a=KKAkSRfTAAAA:8 a=TjqNXoBTBnqrC5BxUBMA:9 a=cvBusfyB2V15izCimMoJ:22 Received: from xanadu.home (xanadu.home [192.168.2.2]) by yoda.home (Postfix) with ESMTP id 6AAA52DA0661; Sun, 24 Jul 2016 11:30:35 -0400 (EDT) From: Nicolas Pitre To: Greg Ungerer , linux-fsdevel@vger.kernel.org Cc: Alan Cox , Alexander Viro , David Howells , linux-arm-kernel@lists.infradead.org, linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 03/15] binfmt_flat: prevent kernel dammage from corrupted executable headers Date: Sun, 24 Jul 2016 11:30:17 -0400 Message-Id: <1469374229-21585-4-git-send-email-nicolas.pitre@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1469374229-21585-1-git-send-email-nicolas.pitre@linaro.org> References: <1469374229-21585-1-git-send-email-nicolas.pitre@linaro.org> X-CMAE-Envelope: MS4wfOjXYC9AqIWKaklKds8Kl7D08T1vkESO3m+8Tk+Agfv3TnmycP3ZmCSuBJEJCedz9qkU4RAjUMav+oPnmXl7fR/k7QDs2i/l80VLPRZ/nO6j0a2rRqKp bka1NDsEgw+KavkQBf5Z3t15lVbARngbBXDKM2sQ12W7u3hymu4pKVYa4p448NL5+wj3p/5xr4sv4fS5MEAMG6wdmQxmTtTVDZkydh+nMG+8R4GZNUY6o4FA dvibcadrA3i1fN62073OtzX23fwH8DGI3qzYmNZnMs7VBwhi7q3coLT+b3dO5lUo0wd/OQNYKcauVpemMISbPkRrzOG1XN19RjSriL6lFtEpKWOy6TQPEydi htpT1jWi0ZTLfiK8nqhwOQUaQ9kNqbhsYsGgP9Ar41JMhDohxOlBT4UFVkt2PpQ7W2qMnzgMnpoCACYt5rVmluQWJneW2APNFDYuScLuFgfZmk5NYDU= Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Signed-off-by: Nicolas Pitre --- fs/binfmt_flat.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index c3ccdefdea..03301bad1f 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -466,6 +466,17 @@ static int load_flat_file(struct linux_binprm *bprm, } /* + * Make sure the header params are sane. + * 28 bits (256 MB) is way more than reasonable in this case. + * If some top bits are set we have probable binary corruption. + */ + if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) { + pr_err("bad header\n"); + ret = -ENOEXEC; + goto err; + } + + /* * fix up the flags for the older format, there were all kinds * of endian hacks, this only works for the simple cases */