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 DD832C433F5 for ; Wed, 18 May 2022 13:36:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238047AbiERNf5 (ORCPT ); Wed, 18 May 2022 09:35:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237969AbiERNfz (ORCPT ); Wed, 18 May 2022 09:35:55 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F362D7E; Wed, 18 May 2022 06:35:45 -0700 (PDT) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 8E23421B1C; Wed, 18 May 2022 13:35:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1652880944; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=LGP99y7W1cFBG0dBgL8R64+Y/eS32761MCmAGvEg25c=; b=YmQucZ6RfzQi/DAT820X+vIS7yRGNDgS7DBlHMGF1SnW1VcFm5ef4kGgYSX3DwAJBTFDBx KsoyXikf8YgSPSwaClEdQJ15m5Eykv1wONty2I2BSPgq+KPT0uWVkebLKL5W3X4Bq1amP5 kbFIgirM8WqnX1JvIxWjjWAj0kjqPXo= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1652880944; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=LGP99y7W1cFBG0dBgL8R64+Y/eS32761MCmAGvEg25c=; b=s65dmcFYA4fZHj/kb3FVv7m4CrsKZpsp1kUUdto0XLH8QeoMy2nv97DenbPMSabYqzEckS fPVgx01oZcQFAAAQ== Received: from quack3.suse.cz (unknown [10.163.43.118]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id DD2F12C141; Wed, 18 May 2022 13:35:43 +0000 (UTC) Received: by quack3.suse.cz (Postfix, from userid 1000) id 91D1EA062F; Wed, 18 May 2022 15:35:43 +0200 (CEST) Date: Wed, 18 May 2022 15:35:43 +0200 From: Jan Kara To: Baokun Li Cc: linux-ext4@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, jack@suse.cz, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, yebin10@huawei.com, yukuai3@huawei.com, Hulk Robot Subject: Re: [PATCH] ext4: fix bug_on in __es_tree_search Message-ID: <20220518133543.eewb4zcsw6fs6zpq@quack3.lan> References: <20220518120816.1541863-1-libaokun1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220518120816.1541863-1-libaokun1@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 18-05-22 20:08:16, Baokun Li wrote: > Hulk Robot reported a BUG_ON: > ================================================================== > kernel BUG at fs/ext4/extents_status.c:199! > [...] > RIP: 0010:ext4_es_end fs/ext4/extents_status.c:199 [inline] > RIP: 0010:__es_tree_search+0x1e0/0x260 fs/ext4/extents_status.c:217 > [...] > Call Trace: > ext4_es_cache_extent+0x109/0x340 fs/ext4/extents_status.c:766 > ext4_cache_extents+0x239/0x2e0 fs/ext4/extents.c:561 > ext4_find_extent+0x6b7/0xa20 fs/ext4/extents.c:964 > ext4_ext_map_blocks+0x16b/0x4b70 fs/ext4/extents.c:4384 > ext4_map_blocks+0xe26/0x19f0 fs/ext4/inode.c:567 > ext4_getblk+0x320/0x4c0 fs/ext4/inode.c:980 > ext4_bread+0x2d/0x170 fs/ext4/inode.c:1031 > ext4_quota_read+0x248/0x320 fs/ext4/super.c:6257 > v2_read_header+0x78/0x110 fs/quota/quota_v2.c:63 > v2_check_quota_file+0x76/0x230 fs/quota/quota_v2.c:82 > vfs_load_quota_inode+0x5d1/0x1530 fs/quota/dquot.c:2368 > dquot_enable+0x28a/0x330 fs/quota/dquot.c:2490 > ext4_quota_enable fs/ext4/super.c:6137 [inline] > ext4_enable_quotas+0x5d7/0x960 fs/ext4/super.c:6163 > ext4_fill_super+0xa7c9/0xdc00 fs/ext4/super.c:4754 > mount_bdev+0x2e9/0x3b0 fs/super.c:1158 > mount_fs+0x4b/0x1e4 fs/super.c:1261 > [...] > ================================================================== > > Above issue may happen as follows: > ------------------------------------- > ext4_fill_super > ext4_enable_quotas > ext4_quota_enable > ext4_iget > __ext4_iget > ext4_ext_check_inode > ext4_ext_check > __ext4_ext_check > ext4_valid_extent_entries > Check for overlapping extents does't take effect > dquot_enable > vfs_load_quota_inode > v2_check_quota_file > v2_read_header > ext4_quota_read > ext4_bread > ext4_getblk > ext4_map_blocks > ext4_ext_map_blocks > ext4_find_extent > ext4_cache_extents > ext4_es_cache_extent > ext4_es_cache_extent > __es_tree_search > ext4_es_end > BUG_ON(es->es_lblk + es->es_len < es->es_lblk) > > The error ext4 extents is as follows: > 0af3 0300 0400 0000 00000000 extent_header > 00000000 0100 0000 12000000 extent1 > 00000000 0100 0000 18000000 extent2 > 02000000 0400 0000 14000000 extent3 > > In the ext4_valid_extent_entries function, > if prev is 0, no error is returned even if lblock<=prev. > This was intended to skip the check on the first extent, but > in the error image above, prev=0+1-1=0 when checking the second extent, > so even though lblock<=prev, the function does not return an error. > As a result, bug_ON occurs in __es_tree_search and the system panics. > > To solve this problem, we only need to check that: > 1. The lblock of the first extent is not less than 0. > 2. The lblock of the next extent is not less than > the next block of the previous extent. > The same applies to extent_idx. > > Fixes: 5946d089379a ("ext4: check for overlapping extents in ext4_valid_extent_entries()") > Reported-by: Hulk Robot > Signed-off-by: Baokun Li Thanks! The patch looks good. Feel free to add: Reviewed-by: Jan Kara Honza > --- > fs/ext4/extents.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > index e473fde6b64b..86ba0db20968 100644 > --- a/fs/ext4/extents.c > +++ b/fs/ext4/extents.c > @@ -372,7 +372,7 @@ static int ext4_valid_extent_entries(struct inode *inode, > { > unsigned short entries; > ext4_lblk_t lblock = 0; > - ext4_lblk_t prev = 0; > + ext4_lblk_t cur = 0; > > if (eh->eh_entries == 0) > return 1; > @@ -396,11 +396,11 @@ static int ext4_valid_extent_entries(struct inode *inode, > > /* Check for overlapping extents */ > lblock = le32_to_cpu(ext->ee_block); > - if ((lblock <= prev) && prev) { > + if (lblock < cur) { > *pblk = ext4_ext_pblock(ext); > return 0; > } > - prev = lblock + ext4_ext_get_actual_len(ext) - 1; > + cur = lblock + ext4_ext_get_actual_len(ext); > ext++; > entries--; > } > @@ -420,13 +420,13 @@ static int ext4_valid_extent_entries(struct inode *inode, > > /* Check for overlapping index extents */ > lblock = le32_to_cpu(ext_idx->ei_block); > - if ((lblock <= prev) && prev) { > + if (lblock < cur) { > *pblk = ext4_idx_pblock(ext_idx); > return 0; > } > ext_idx++; > entries--; > - prev = lblock; > + cur = lblock + 1; > } > } > return 1; > -- > 2.31.1 > -- Jan Kara SUSE Labs, CR