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=-7.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT 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 6BF36C43441 for ; Mon, 19 Nov 2018 16:40:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 353A62145D for ; Mon, 19 Nov 2018 16:40:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="YShjECQW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 353A62145D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733078AbeKTDEv (ORCPT ); Mon, 19 Nov 2018 22:04:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:37980 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732128AbeKTDEu (ORCPT ); Mon, 19 Nov 2018 22:04:50 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 13259206BA; Mon, 19 Nov 2018 16:40:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542645640; bh=8lhJj9g/igikTj5pWXPs+rt1odZ1uwvBfgrM2UvT8us=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YShjECQWzw8JeyEAjwKQvg4gd+PVvB9O5CMuY8f3Gs+hD7qpvz8zO+oU0kFrUc0Ro DsKv3ScUrvY3icWBIP2dHE4MlcbsArmcp8dBEDR8B5D7v6/voDaA4mOHcCMnPpKMet BzQw7+QiC4errhYny1xF8xKpUPQ9dcjdbpxYm6EU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Kara , Sasha Levin Subject: [PATCH 4.18 032/171] udf: Prevent write-unsupported filesystem to be remounted read-write Date: Mon, 19 Nov 2018 17:27:08 +0100 Message-Id: <20181119162625.038921820@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181119162618.909354448@linuxfoundation.org> References: <20181119162618.909354448@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jan Kara [ Upstream commit a9ad01bc759df79b0012f43ee52164391e31cd96 ] There are certain filesystem features which we support for reading but not for writing. We properly refuse to mount such filesystems read-write however for some features (such as read-only partitions), we don't check for these features when remounting the filesystem from read-only to read-write. Thus such filesystems could be remounted read-write leading to strange behavior (most likely crashes). Fix the problem by marking in superblock whether the filesystem has some features that are supported in read-only mode and check this flag during remount. Signed-off-by: Jan Kara Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/udf/super.c | 30 ++++++++++++++++-------------- fs/udf/udf_sb.h | 2 ++ 2 files changed, 18 insertions(+), 14 deletions(-) --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -613,14 +613,11 @@ static int udf_remount_fs(struct super_b struct udf_options uopt; struct udf_sb_info *sbi = UDF_SB(sb); int error = 0; - struct logicalVolIntegrityDescImpUse *lvidiu = udf_sb_lvidiu(sb); + + if (!(*flags & SB_RDONLY) && UDF_QUERY_FLAG(sb, UDF_FLAG_RW_INCOMPAT)) + return -EACCES; sync_filesystem(sb); - if (lvidiu) { - int write_rev = le16_to_cpu(lvidiu->minUDFWriteRev); - if (write_rev > UDF_MAX_WRITE_VERSION && !(*flags & SB_RDONLY)) - return -EACCES; - } uopt.flags = sbi->s_flags; uopt.uid = sbi->s_uid; @@ -1317,6 +1314,7 @@ static int udf_load_partdesc(struct supe ret = -EACCES; goto out_bh; } + UDF_SET_FLAG(sb, UDF_FLAG_RW_INCOMPAT); ret = udf_load_vat(sb, i, type1_idx); if (ret < 0) goto out_bh; @@ -2215,10 +2213,12 @@ static int udf_fill_super(struct super_b UDF_MAX_READ_VERSION); ret = -EINVAL; goto error_out; - } else if (minUDFWriteRev > UDF_MAX_WRITE_VERSION && - !sb_rdonly(sb)) { - ret = -EACCES; - goto error_out; + } else if (minUDFWriteRev > UDF_MAX_WRITE_VERSION) { + if (!sb_rdonly(sb)) { + ret = -EACCES; + goto error_out; + } + UDF_SET_FLAG(sb, UDF_FLAG_RW_INCOMPAT); } sbi->s_udfrev = minUDFWriteRev; @@ -2236,10 +2236,12 @@ static int udf_fill_super(struct super_b } if (sbi->s_partmaps[sbi->s_partition].s_partition_flags & - UDF_PART_FLAG_READ_ONLY && - !sb_rdonly(sb)) { - ret = -EACCES; - goto error_out; + UDF_PART_FLAG_READ_ONLY) { + if (!sb_rdonly(sb)) { + ret = -EACCES; + goto error_out; + } + UDF_SET_FLAG(sb, UDF_FLAG_RW_INCOMPAT); } if (udf_find_fileset(sb, &fileset, &rootdir)) { --- a/fs/udf/udf_sb.h +++ b/fs/udf/udf_sb.h @@ -30,6 +30,8 @@ #define UDF_FLAG_LASTBLOCK_SET 16 #define UDF_FLAG_BLOCKSIZE_SET 17 #define UDF_FLAG_INCONSISTENT 18 +#define UDF_FLAG_RW_INCOMPAT 19 /* Set when we find RW incompatible + * feature */ #define UDF_PART_FLAG_UNALLOC_BITMAP 0x0001 #define UDF_PART_FLAG_UNALLOC_TABLE 0x0002