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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 72737ECAAD5 for ; Thu, 8 Sep 2022 04:04:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229698AbiIHEEc (ORCPT ); Thu, 8 Sep 2022 00:04:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60028 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229437AbiIHEE3 (ORCPT ); Thu, 8 Sep 2022 00:04:29 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3E6902ACF for ; Wed, 7 Sep 2022 21:04:26 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A65F561ADE for ; Thu, 8 Sep 2022 04:04:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDBA6C433D6; Thu, 8 Sep 2022 04:04:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1662609865; bh=Pfin36yBLsukYe8SxnQDOOnpwg+6JrrFz2Da5ksuDMs=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=t5uQD0Q62vRDkpq8WSGrOioapgY0CfwupxkOvS43tvfhGtfd7YwCBjH2g5XtG4qHV hjqe30gZhGCW9LAokV8GqL81N8CT7acbkiMUxfq5r/gdSlWYdan7LnErkjzxoNZzEt IC8OjxgCDO1R2JXtmsY4c9qzNstU1t7L4Q42cLdwFhOWG6GW4Sm/jB6MKuE6oUNWMk 5nVMwG6UnzCZfj8TFQ2SjUqIz1sctnSyuPtQXKeChT0SR34L6WclaI/7mVaejdOFQE wk4DImX/z6d3nP2A/4eYF6oML5bHM4Z1yB6kfAxQ7DhfY6TpsqbUHdTSy7IGm5kFlq Pk2IEqcuDEETg== Message-ID: Date: Thu, 8 Sep 2022 12:04:20 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH v2] f2fs: fix to disallow getting inner inode via f2fs_iget() Content-Language: en-US To: Jaegeuk Kim Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Chao Yu References: <20220830225358.300027-1-chao@kernel.org> <0af788ed-8797-22a2-ae0c-433fdd6a2188@kernel.org> From: Chao Yu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/9/8 10:19, Jaegeuk Kim wrote: > On 09/08, Chao Yu wrote: >> On 2022/9/8 10:02, Jaegeuk Kim wrote: >>> On 08/31, Chao Yu wrote: >>>> From: Chao Yu >>>> >>>> Introduce f2fs_iget_inner() for f2fs_fill_super() to get inner inode: >>>> meta inode, node inode or compressed inode, and add f2fs_check_nid_range() >>>> in f2fs_iget() to avoid getting inner inode from external interfaces. >>> >>> So, we don't want to check the range of inner inode numbers? What'd be the >>> way to check it's okay? >> >> For node_ino, meta_ino, root_ino, we have checked them in sanity_check_raw_super() >> as below: >> >> /* check reserved ino info */ >> if (le32_to_cpu(raw_super->node_ino) != 1 || >> le32_to_cpu(raw_super->meta_ino) != 2 || >> le32_to_cpu(raw_super->root_ino) != 3) { >> f2fs_info(sbi, "Invalid Fs Meta Ino: node(%u) meta(%u) root(%u)", >> le32_to_cpu(raw_super->node_ino), >> le32_to_cpu(raw_super->meta_ino), >> le32_to_cpu(raw_super->root_ino)); >> return -EFSCORRUPTED; >> } >> >> compressed_ino should always be NM_I(sbi)->max_nid, it can be checked in >> f2fs_init_compress_inode()? > > Hmm, I'm not sure whether we really need this patch, since it'd look better > to handle all the iget with single f2fs_iget? Well, the main concern is previously f2fs_iget() won't check validation for inner inode due to it will skip do_read_inode() - f2fs_check_nid_range(), so that in a fuzzed image, caller may pass inner ino into f2fs_iget(), result in incorrect use of inner inode. So I add f2fs_check_nid_range() in prior to f2fs_iget_inner() in f2fs_iget() as below to detect and avoid this case. >>>> +struct inode *f2fs_iget(struct super_block *sb, unsigned long ino) >>>> +{ >>>> + int ret; >>>> + >>>> + ret = f2fs_check_nid_range(F2FS_SB(sb), ino); >>>> + if (ret) >>>> + return ERR_PTR(ret); >>>> + >>>> + return f2fs_iget_inner(sb, ino);