From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 903C5C282DB for ; Sun, 3 Feb 2019 14:01:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E5A620815 for ; Sun, 3 Feb 2019 14:01:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729578AbfBCOBF (ORCPT ); Sun, 3 Feb 2019 09:01:05 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:53342 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728146AbfBCNtu (ORCPT ); Sun, 3 Feb 2019 08:49:50 -0500 Received: from cable-78.29.236.164.coditel.net ([78.29.236.164] helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gqI9d-0003tf-8a; Sun, 03 Feb 2019 13:49:49 +0000 Received: from ben by deadeye with local (Exim 4.92-RC4) (envelope-from ) id 1gqI9a-00071O-1e; Sun, 03 Feb 2019 14:49:46 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Nicolas Pitre" , "Nicolas Pitre" , "Anatoly Trosinenko" Date: Sun, 03 Feb 2019 14:45:08 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 128/305] Cramfs: fix abad comparison when wrap-arounds occur In-Reply-To: X-SA-Exim-Connect-IP: 78.29.236.164 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.63-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Nicolas Pitre commit 672ca9dd13f1aca0c17516f76fc5b0e8344b3e46 upstream. It is possible for corrupted filesystem images to produce very large block offsets that may wrap when a length is added, and wrongly pass the buffer size test. Reported-by: Anatoly Trosinenko Signed-off-by: Nicolas Pitre Signed-off-by: Ben Hutchings --- fs/cramfs/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/cramfs/inode.c +++ b/fs/cramfs/inode.c @@ -183,7 +183,8 @@ static void *cramfs_read(struct super_bl continue; blk_offset = (blocknr - buffer_blocknr[i]) << PAGE_CACHE_SHIFT; blk_offset += offset; - if (blk_offset + len > BUFFER_SIZE) + if (blk_offset > BUFFER_SIZE || + blk_offset + len > BUFFER_SIZE) continue; return read_buffers[i] + blk_offset; }