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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 BA37AC433FF for ; Tue, 6 Aug 2019 01:28:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 84A73216B7 for ; Tue, 6 Aug 2019 01:28:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565054922; bh=KnLY1sAJ7ObFvAXL3EPBllmg22XMnePEwMFus9ls9Uc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=AtfsSJe1FnRXnxIVvCEidAdJ2jhpQQbFchIWfh2l38x49ja/hXxSo33YR0p23GO4D cQ/D71evpViUt2GSWhBwUNrCU8eIO94TqZABD4+QLhY+i6A5Av4JRMFMTKqUsngEgw V8jt8dKz/AMT6AqRPFtVSYvW37WVY/2lBKm0EzuM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731241AbfHFB2l (ORCPT ); Mon, 5 Aug 2019 21:28:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:37522 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728870AbfHFB2k (ORCPT ); Mon, 5 Aug 2019 21:28:40 -0400 Received: from localhost (unknown [104.132.0.81]) (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 CCC592147A; Tue, 6 Aug 2019 01:28:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565054919; bh=KnLY1sAJ7ObFvAXL3EPBllmg22XMnePEwMFus9ls9Uc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=0zWqr68TcP+9F8cFVvHxfxnP2RZnRTkMHBKP/fAw2rF14+rdMrRy3hBa8l1iq5lkX JvUoidCCMZemeRklpULqGSnW3yoR7gWkN5fqYyWGb5VMuH4B9D9QLFPJDjO3BQ+jRw lzVQ67jhsbsFGxg3vtHFUmQ9mYGw0R9Lien6XcoU= Date: Mon, 5 Aug 2019 18:28:39 -0700 From: Jaegeuk Kim To: Chao Yu Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, chao@kernel.org Subject: Re: [PATCH] Revert "f2fs: avoid out-of-range memory access" Message-ID: <20190806012839.GD1029@jaegeuk-macbookpro.roam.corp.google.com> References: <20190802101548.96543-1-yuchao0@huawei.com> <20190806004215.GC98101@jaegeuk-macbookpro.roam.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.8.2 (2017-04-18) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/06, Chao Yu wrote: > On 2019/8/6 8:42, Jaegeuk Kim wrote: > > On 08/02, Chao Yu wrote: > >> As Pavel Machek reported: > >> > >> "We normally use -EUCLEAN to signal filesystem corruption. Plus, it is > >> good idea to report it to the syslog and mark filesystem as "needing > >> fsck" if filesystem can do that." > >> > >> Still we need improve the original patch with: > >> - use unlikely keyword > >> - add message print > >> - return EUCLEAN > >> > >> However, after rethink this patch, I don't think we should add such > >> condition check here as below reasons: > >> - We have already checked the field in f2fs_sanity_check_ckpt(), > >> - If there is fs corrupt or security vulnerability, there is nothing > >> to guarantee the field is integrated after the check, unless we do > >> the check before each of its use, however no filesystem does that. > >> - We only have similar check for bitmap, which was added due to there > >> is bitmap corruption happened on f2fs' runtime in product. > >> - There are so many key fields in SB/CP/NAT did have such check > >> after f2fs_sanity_check_{sb,cp,..}. > >> > >> So I propose to revert this unneeded check. > > > > IIRC, this came from security vulnerability report which can access > > I don't think that's correct report, since we have checked validation of that > field during mount, if it can be ruined after that, any variables can't be trusted. I assumed this was reproduced with a fuzzed image. I'll check it with Ocean. > > Now we just check bitmaps at real-time, because we have encountered such bitmap > corruption in product. > > Thanks, > > > out-of-boundary memory region. Could you write another patch to address the > > above issues? > > > >> > >> This reverts commit 56f3ce675103e3fb9e631cfb4131fc768bc23e9a. > >> > >> Signed-off-by: Chao Yu > >> --- > >> fs/f2fs/segment.c | 5 ----- > >> 1 file changed, 5 deletions(-) > >> > >> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > >> index 9693fa4c8971..2eff9c008ae0 100644 > >> --- a/fs/f2fs/segment.c > >> +++ b/fs/f2fs/segment.c > >> @@ -3492,11 +3492,6 @@ static int read_compacted_summaries(struct f2fs_sb_info *sbi) > >> seg_i = CURSEG_I(sbi, i); > >> segno = le32_to_cpu(ckpt->cur_data_segno[i]); > >> blk_off = le16_to_cpu(ckpt->cur_data_blkoff[i]); > >> - if (blk_off > ENTRIES_IN_SUM) { > >> - f2fs_bug_on(sbi, 1); > >> - f2fs_put_page(page, 1); > >> - return -EFAULT; > >> - } > >> seg_i->next_segno = segno; > >> reset_curseg(sbi, i, 0); > >> seg_i->alloc_type = ckpt->alloc_type[i]; > >> -- > >> 2.18.0.rc1 > > . > >