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=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 4783BC432C0 for ; Tue, 3 Dec 2019 22:57:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 106D520656 for ; Tue, 3 Dec 2019 22:57:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575413879; bh=iuNjQ46ZvPenrzQWoSNSZF0zXRLuNcDpd2AvYkeFFKw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vOS/tTd0ZWR1ZGis3/5lvbvn54dE2GPuGweh0kS7OMejBYDdEMS9ed18Q8xkSYpl+ y5e9ZJS78IsJftJDMusN9IWcBkychn3xFI5yt3HYvkdxWDTXBaYqtZ+9wDqKCES2v/ 5UQvt12emTtgIXwDoBrv8FN5zKZb7I2RxWhZZkYw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730609AbfLCW56 (ORCPT ); Tue, 3 Dec 2019 17:57:58 -0500 Received: from mail.kernel.org ([198.145.29.99]:53984 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729866AbfLCW55 (ORCPT ); Tue, 3 Dec 2019 17:57:57 -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 39C8F2053B; Tue, 3 Dec 2019 22:57:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575413875; bh=iuNjQ46ZvPenrzQWoSNSZF0zXRLuNcDpd2AvYkeFFKw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1y452eiujOFiivufFdQ/DePcWIsodPKF90IzKGgzUBa2ZC2hfFpEf+mwSij3n9bsG W/f8nOg4lfaprvdL8eC8Pt9y89xHUFjMCukHEPoc4d9oyI6skM47OOt1Szz4laufbq cCtjZ2tWhO6HSossI6bvPF3FlRsmpYVWo9wnbkpQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+f8d6f8386ceacdbfff57@syzkaller.appspotmail.com, syzbot+33d7ea72e47de3bdf4e1@syzkaller.appspotmail.com, syzbot+44b6763edfc17144296f@syzkaller.appspotmail.com, Theodore Tso , stable@kernel.org Subject: [PATCH 4.19 294/321] ext4: add more paranoia checking in ext4_expand_extra_isize handling Date: Tue, 3 Dec 2019 23:36:00 +0100 Message-Id: <20191203223442.449933084@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191203223427.103571230@linuxfoundation.org> References: <20191203223427.103571230@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: Theodore Ts'o commit 4ea99936a1630f51fc3a2d61a58ec4a1c4b7d55a upstream. It's possible to specify a non-zero s_want_extra_isize via debugging option, and this can cause bad things(tm) to happen when using a file system with an inode size of 128 bytes. Add better checking when the file system is mounted, as well as when we are actually doing the trying to do the inode expansion. Link: https://lore.kernel.org/r/20191110121510.GH23325@mit.edu Reported-by: syzbot+f8d6f8386ceacdbfff57@syzkaller.appspotmail.com Reported-by: syzbot+33d7ea72e47de3bdf4e1@syzkaller.appspotmail.com Reported-by: syzbot+44b6763edfc17144296f@syzkaller.appspotmail.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/ext4/inode.c | 15 +++++++++++++++ fs/ext4/super.c | 21 ++++++++++++--------- 2 files changed, 27 insertions(+), 9 deletions(-) --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5904,8 +5904,23 @@ static int __ext4_expand_extra_isize(str { struct ext4_inode *raw_inode; struct ext4_xattr_ibody_header *header; + unsigned int inode_size = EXT4_INODE_SIZE(inode->i_sb); + struct ext4_inode_info *ei = EXT4_I(inode); int error; + /* this was checked at iget time, but double check for good measure */ + if ((EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > inode_size) || + (ei->i_extra_isize & 3)) { + EXT4_ERROR_INODE(inode, "bad extra_isize %u (inode size %u)", + ei->i_extra_isize, + EXT4_INODE_SIZE(inode->i_sb)); + return -EFSCORRUPTED; + } + if ((new_extra_isize < ei->i_extra_isize) || + (new_extra_isize < 4) || + (new_extra_isize > inode_size - EXT4_GOOD_OLD_INODE_SIZE)) + return -EINVAL; /* Should never happen */ + raw_inode = ext4_raw_inode(iloc); header = IHDR(inode, raw_inode); --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3517,12 +3517,15 @@ static void ext4_clamp_want_extra_isize( { struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_super_block *es = sbi->s_es; + unsigned def_extra_isize = sizeof(struct ext4_inode) - + EXT4_GOOD_OLD_INODE_SIZE; - /* 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 == 0) { - sbi->s_want_extra_isize = sizeof(struct ext4_inode) - - EXT4_GOOD_OLD_INODE_SIZE; + if (sbi->s_inode_size == EXT4_GOOD_OLD_INODE_SIZE) { + sbi->s_want_extra_isize = 0; + return; + } + if (sbi->s_want_extra_isize < 4) { + sbi->s_want_extra_isize = def_extra_isize; if (ext4_has_feature_extra_isize(sb)) { if (sbi->s_want_extra_isize < le16_to_cpu(es->s_want_extra_isize)) @@ -3535,10 +3538,10 @@ static void ext4_clamp_want_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; + if ((sbi->s_want_extra_isize > sbi->s_inode_size) || + (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize > + sbi->s_inode_size)) { + sbi->s_want_extra_isize = def_extra_isize; ext4_msg(sb, KERN_INFO, "required extra inode space not available"); }