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 1A939C2D0DB for ; Wed, 22 Jan 2020 09:30:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E4C1924686 for ; Wed, 22 Jan 2020 09:30:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579685446; bh=9AZ9BxagyitRM0YNDbVWEI38GtxSwOXgWFLshHNpqmo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Hu9AHICtHg8cH6Skfwwf1YxiWoDgUZB5msCIFgnGh4iuL7jbcnsU57mSRF9rD+7Ak 2ZVpIWdV3A+YPphg2UZg+m272uu/hBLZ6+ihVAdz4Vy0MrML9gpW4JzU86r4xxqmbS 5+8RjW/KytdnjcUUeSmncCdjODLA6W60aze6Ws4c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729290AbgAVJak (ORCPT ); Wed, 22 Jan 2020 04:30:40 -0500 Received: from mail.kernel.org ([198.145.29.99]:42224 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729277AbgAVJaj (ORCPT ); Wed, 22 Jan 2020 04:30:39 -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 54CAB24672; Wed, 22 Jan 2020 09:30:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579685438; bh=9AZ9BxagyitRM0YNDbVWEI38GtxSwOXgWFLshHNpqmo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=If1yd+xeNjhkY/HbpHFyex/01rg9OkIjezsuZ0MOaHqDPzF/x26FcU8YFENPAeR0N +89ecimS+nXQRtfeSMnjCXbWW/kNMMFYb/f8FFji2YDKXXmBhXH5Ot9B2N+KYTKnkF RzClOEUVt3vKAcjvhYnFb/JNUDjZYuW+FdX7SRcY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+f584efa0ac7213c226b7@syzkaller.appspotmail.com, Jan Kara , Barret Rhoden , Theodore Tso , Ben Hutchings Subject: [PATCH 4.4 15/76] ext4: fix use-after-free race with debug_want_extra_isize Date: Wed, 22 Jan 2020 10:28:31 +0100 Message-Id: <20200122092753.100629343@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200122092751.587775548@linuxfoundation.org> References: <20200122092751.587775548@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Barret Rhoden commit 7bc04c5c2cc467c5b40f2b03ba08da174a0d5fa7 upstream. When remounting with debug_want_extra_isize, we were not performing the same checks that we do during a normal mount. That allowed us to set a value for s_want_extra_isize that reached outside the s_inode_size. Fixes: e2b911c53584 ("ext4: clean up feature test macros with predicate functions") Reported-by: syzbot+f584efa0ac7213c226b7@syzkaller.appspotmail.com Reviewed-by: Jan Kara Signed-off-by: Barret Rhoden Signed-off-by: Theodore Ts'o [bwh: Backported to 4.4: The debug_want_extra_isize mount option is not supported] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- fs/ext4/super.c | 56 +++++++++++++++++++++++++++++++++----------------------- 1 file changed, 33 insertions(+), 23 deletions(-) --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3169,6 +3169,36 @@ int ext4_calculate_overhead(struct super return 0; } +static void ext4_clamp_want_extra_isize(struct super_block *sb) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + struct ext4_super_block *es = sbi->s_es; + + /* determine the minimum size of new large inodes, if present */ + if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) { + sbi->s_want_extra_isize = sizeof(struct ext4_inode) - + EXT4_GOOD_OLD_INODE_SIZE; + if (ext4_has_feature_extra_isize(sb)) { + if (sbi->s_want_extra_isize < + le16_to_cpu(es->s_want_extra_isize)) + sbi->s_want_extra_isize = + le16_to_cpu(es->s_want_extra_isize); + if (sbi->s_want_extra_isize < + le16_to_cpu(es->s_min_extra_isize)) + sbi->s_want_extra_isize = + le16_to_cpu(es->s_min_extra_isize); + } + } + /* Check if enough inode space is available */ + if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize > + sbi->s_inode_size) { + sbi->s_want_extra_isize = sizeof(struct ext4_inode) - + EXT4_GOOD_OLD_INODE_SIZE; + ext4_msg(sb, KERN_INFO, + "required extra inode space not available"); + } +} + static void ext4_set_resv_clusters(struct super_block *sb) { ext4_fsblk_t resv_clusters; @@ -3991,29 +4021,7 @@ no_journal: if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY)) sb->s_flags |= MS_RDONLY; - /* determine the minimum size of new large inodes, if present */ - if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) { - sbi->s_want_extra_isize = sizeof(struct ext4_inode) - - EXT4_GOOD_OLD_INODE_SIZE; - if (ext4_has_feature_extra_isize(sb)) { - if (sbi->s_want_extra_isize < - le16_to_cpu(es->s_want_extra_isize)) - sbi->s_want_extra_isize = - le16_to_cpu(es->s_want_extra_isize); - if (sbi->s_want_extra_isize < - le16_to_cpu(es->s_min_extra_isize)) - sbi->s_want_extra_isize = - le16_to_cpu(es->s_min_extra_isize); - } - } - /* Check if enough inode space is available */ - if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize > - sbi->s_inode_size) { - sbi->s_want_extra_isize = sizeof(struct ext4_inode) - - EXT4_GOOD_OLD_INODE_SIZE; - ext4_msg(sb, KERN_INFO, "required extra inode space not" - "available"); - } + ext4_clamp_want_extra_isize(sb); ext4_set_resv_clusters(sb); @@ -4766,6 +4774,8 @@ static int ext4_remount(struct super_blo goto restore_opts; } + ext4_clamp_want_extra_isize(sb); + if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^ test_opt(sb, JOURNAL_CHECKSUM)) { ext4_msg(sb, KERN_ERR, "changing journal_checksum "