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 64160ECAAA1 for ; Tue, 13 Sep 2022 01:26:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229836AbiIMB0S (ORCPT ); Mon, 12 Sep 2022 21:26:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60774 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229737AbiIMB0P (ORCPT ); Mon, 12 Sep 2022 21:26:15 -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 D77814BD1A for ; Mon, 12 Sep 2022 18:26:14 -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 5D4AE612CE for ; Tue, 13 Sep 2022 01:26:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3428C433D6; Tue, 13 Sep 2022 01:26:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663032373; bh=ahK3Hn9gj376IQfXm5Ze9rTSg34hVz4QwVp7njYLSnA=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=NR8E5EHYMVDxlO6TR0DAqqJSO2oHvfFZQHYaX9ci/icVlWM6i3keHzAIB7tgArR4/ qfmYpiYHdVOqpP/V5ETk0OsxudzvHQ0cdhlS3HedyJE6Zb54JUdSuPiKpd6jbGIMoI 6cRhMJ4SxIjYJJrFCTRLwffKj9vs9n8+cu6Q/xgw662N7fhGRrW5gODuNx2JM0jfJP 4LdGvdtBPLsinVGnjFDeNDcmDOrhLUFfNRL4VcMZ21UBQtiC0nYcNpNDN09pjLnUvL rqRvjfyLMaisSqR2gF7MbVkq7jlINiAyDqXohRZBUDSl1nToyLuZR9OlZN2NMdVQO9 ETjju1DffZ0cw== Message-ID: <6c54e0b1-9c75-af90-565b-61174ddb5cbc@kernel.org> Date: Tue, 13 Sep 2022 09:26:01 +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 2022/9/12 23:39, Jaegeuk Kim wrote: > On 09/08, Chao Yu wrote: >> 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. > > FWIW, sanity_check_raw_super() checked the inode numbers. However, previously, f2fs_iget() will return inner inode to caller directly, if caller passes meta_ino, node_ino or compress_ino to f2fs_iget()? Thanks, > >> >>>>>> +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);