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 3CE0FECAAA1 for ; Tue, 13 Sep 2022 02:33:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229817AbiIMCdj (ORCPT ); Mon, 12 Sep 2022 22:33:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44448 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229681AbiIMCdi (ORCPT ); Mon, 12 Sep 2022 22:33:38 -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 7C3E452E5D; Mon, 12 Sep 2022 19:33:37 -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 DD413612FE; Tue, 13 Sep 2022 02:33:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 40C51C433C1; Tue, 13 Sep 2022 02:33:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663036416; bh=ZDvCgiFrql+qDgOo1QGy7zMojVL4tdh1vZx8YEL/VII=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=redTRotvVXGPYvrWNBYIzMaT+xVKiI/0oYKvSZQR775pTGflycJSTD7HjXbEnCXCW BhBdvyNb1aVlCWPgPIHy1GitaiL+KS4EKiQUxbYBHELneFnWzi/DFB2LP2tdK+6F/F n2XkZsN60cEyJjtvZ53PRhW3OAybAQm7Fqt9caxzwOjbEt9q2SGpwEoaJe/6H6ZXRB mU8Af3azOrHMLVFcZsotx2nHNv43VMgi+ly9YpA6vCTTDj0ZBhp2WInexEf3j+AnNp ZbSjfmKVM8Osoqx1htTn45w7OEPEwqTa0uf2WlqenQEwvGrqD6/JJLDO/STCa8Sex6 wgPax2UYgH8Sw== Message-ID: Date: Tue, 13 Sep 2022 10:33:29 +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] f2fs: fix to detect obsolete inner inode during fill_super() Content-Language: en-US To: Jaegeuk Kim Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, stable@vger.kernel.org, syzbot+775a3440817f74fddb8c@syzkaller.appspotmail.com References: <20220908105334.98572-1-chao@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: stable@vger.kernel.org On 2022/9/12 23:37, Jaegeuk Kim wrote: > On 09/08, Chao Yu wrote: >> Sometimes we can get a cached meta_inode which has no aops yet. Let's set it >> all the time to fix the below panic. >> >> Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 >> Mem abort info: >> ESR = 0x0000000086000004 >> EC = 0x21: IABT (current EL), IL = 32 bits >> SET = 0, FnV = 0 >> EA = 0, S1PTW = 0 >> FSC = 0x04: level 0 translation fault >> user pgtable: 4k pages, 48-bit VAs, pgdp=0000000109ee4000 >> [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 >> Internal error: Oops: 86000004 [#1] PREEMPT SMP >> Modules linked in: >> CPU: 1 PID: 3045 Comm: syz-executor330 Not tainted 6.0.0-rc2-syzkaller-16455-ga41a877bc12d #0 >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 >> pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) >> pc : 0x0 >> lr : folio_mark_dirty+0xbc/0x208 mm/page-writeback.c:2748 >> sp : ffff800012783970 >> x29: ffff800012783970 x28: 0000000000000000 x27: ffff800012783b08 >> x26: 0000000000000001 x25: 0000000000000400 x24: 0000000000000001 >> x23: ffff0000c736e000 x22: 0000000000000045 x21: 05ffc00000000015 >> x20: ffff0000ca7403b8 x19: fffffc00032ec600 x18: 0000000000000181 >> x17: ffff80000c04d6bc x16: ffff80000dbb8658 x15: 0000000000000000 >> x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 >> x11: ff808000083e9814 x10: 0000000000000000 x9 : ffff8000083e9814 >> x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000 >> x5 : ffff0000cbb19000 x4 : ffff0000cb3d2000 x3 : ffff0000cbb18f80 >> x2 : fffffffffffffff0 x1 : fffffc00032ec600 x0 : ffff0000ca7403b8 >> Call trace: >> 0x0 >> set_page_dirty+0x38/0xbc mm/folio-compat.c:62 >> f2fs_update_meta_page+0x80/0xa8 fs/f2fs/segment.c:2369 >> do_checkpoint+0x794/0xea8 fs/f2fs/checkpoint.c:1522 >> f2fs_write_checkpoint+0x3b8/0x568 fs/f2fs/checkpoint.c:1679 >> >> The root cause is, quoted from Jaegeuk: >> >> It turned out there is a bug in reiserfs which doesn't free the root >> inode (ino=2). That leads f2fs to find an ino=2 with the previous >> superblock point used by reiserfs. That stale inode has no valid >> mapping that f2fs can use, result in kernel panic. >> >> This patch adds sanity check in f2fs_iget() to avoid finding stale >> inode during inner inode initialization. >> >> Cc: stable@vger.kernel.org >> Reported-by: syzbot+775a3440817f74fddb8c@syzkaller.appspotmail.com >> Signed-off-by: Jaegeuk Kim >> Signed-off-by: Chao Yu >> --- >> fs/f2fs/inode.c | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c >> index ccb29034af59..df1a82fbfaf2 100644 >> --- a/fs/f2fs/inode.c >> +++ b/fs/f2fs/inode.c >> @@ -493,6 +493,17 @@ struct inode *f2fs_iget_inner(struct super_block *sb, unsigned long ino) >> struct inode *inode; >> int ret = 0; >> >> + if (ino == F2FS_NODE_INO(sbi) || ino == F2FS_META_INO(sbi) || >> + ino == F2FS_COMPRESS_INO(sbi)) { >> + inode = ilookup(sb, ino); >> + if (inode) { >> + iput(inode); >> + f2fs_err(sbi, "there is obsoleted inner inode %lu cached in hash table", >> + ino); >> + return ERR_PTR(-EFSCORRUPTED); > > Well, this does not indicate f2fs is corrupted. I'd rather expect to fix > reiserfs instead of f2fs workaround which hides the bug. Well, is there a fixing patch for reiserfs? If not, how about applying this patch first, later, we can revert it after reiserfs has been fixed. Thanks, > >> + } >> + } >> + >> inode = iget_locked(sb, ino); >> if (!inode) >> return ERR_PTR(-ENOMEM); >> -- >> 2.25.1