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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 8AF0EC3276C for ; Thu, 2 Jan 2020 22:38:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5577620863 for ; Thu, 2 Jan 2020 22:38:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578004698; bh=srK+AwUov53SvNhhGdeEi7tX841wok/s60+s1aXhuaE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zRAWDfsKLU8/AIzB12hcin/OifgkUn4YquswVMYPP9eSWOVfPvVtRZSzn1TZ118jD bBNUpmVCScil3dSy15DQoufkesPp5dH381YLbv53V+oEaJ4vXYnmGjep9nerkwojIN PEYjng9W5IQaBbhuCJRi+jUinC+I9KrRraJg/KMo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730805AbgABWiR (ORCPT ); Thu, 2 Jan 2020 17:38:17 -0500 Received: from mail.kernel.org ([198.145.29.99]:51876 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731281AbgABWiO (ORCPT ); Thu, 2 Jan 2020 17:38:14 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 10E22222C3; Thu, 2 Jan 2020 22:38:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578004693; bh=srK+AwUov53SvNhhGdeEi7tX841wok/s60+s1aXhuaE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vlBwve8irORoQVtd7C5ZqOOU8gtHprZcIP3JZizjBm3e7OCzHkz4HfSdJVxLLTCAx MNoQBdlSMFidkiAhGz3wVwMfLrvBvkPsTop86FRqYH7JQBBGuNOvo8igQxLrFibDHf untPmMuqbybm3ehzbag2Kzcq32K0HAw0jCFUDDek= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Kara , Theodore Tso Subject: [PATCH 4.4 086/137] ext4: check for directory entries too close to block end Date: Thu, 2 Jan 2020 23:07:39 +0100 Message-Id: <20200102220558.244529402@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200102220546.618583146@linuxfoundation.org> References: <20200102220546.618583146@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jan Kara commit 109ba779d6cca2d519c5dd624a3276d03e21948e upstream. ext4_check_dir_entry() currently does not catch a case when a directory entry ends so close to the block end that the header of the next directory entry would not fit in the remaining space. This can lead to directory iteration code trying to access address beyond end of current buffer head leading to oops. CC: stable@vger.kernel.org Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20191202170213.4761-3-jack@suse.cz Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/dir.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/fs/ext4/dir.c +++ b/fs/ext4/dir.c @@ -75,6 +75,11 @@ int __ext4_check_dir_entry(const char *f error_msg = "rec_len is too small for name_len"; else if (unlikely(((char *) de - buf) + rlen > size)) error_msg = "directory entry overrun"; + else if (unlikely(((char *) de - buf) + rlen > + size - EXT4_DIR_REC_LEN(1) && + ((char *) de - buf) + rlen != size)) { + error_msg = "directory entry too close to block end"; + } else if (unlikely(le32_to_cpu(de->inode) > le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count))) error_msg = "inode out of bounds";