From patchwork Thu Jan 4 14:20:33 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baokun Li X-Patchwork-Id: 1882457 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org (client-ip=150.107.74.76; helo=gandalf.ozlabs.org; envelope-from=srs0=fegm=io=vger.kernel.org=linux-ext4+bounces-692-patchwork-incoming=ozlabs.org@ozlabs.org; receiver=patchwork.ozlabs.org) Received: from gandalf.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4T5TG14s2Hz23dg for ; Fri, 5 Jan 2024 01:18:17 +1100 (AEDT) Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4T5TG14LPsz4wcH for ; Fri, 5 Jan 2024 01:18:17 +1100 (AEDT) Received: by gandalf.ozlabs.org (Postfix) id 4T5TG14GKMz4xGM; Fri, 5 Jan 2024 01:18:17 +1100 (AEDT) Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: gandalf.ozlabs.org; dmarc=fail (p=quarantine dis=none) header.from=huawei.com Authentication-Results: gandalf.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2604:1380:40f1:3f00::1; helo=sy.mirrors.kernel.org; envelope-from=linux-ext4+bounces-692-patchwork-incoming=ozlabs.org@vger.kernel.org; receiver=ozlabs.org) Received: from sy.mirrors.kernel.org (sy.mirrors.kernel.org [IPv6:2604:1380:40f1:3f00::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by gandalf.ozlabs.org (Postfix) with ESMTPS id 4T5TG13qBkz4wcH for ; Fri, 5 Jan 2024 01:18:17 +1100 (AEDT) Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sy.mirrors.kernel.org (Postfix) with ESMTPS id 4871EB24774 for ; Thu, 4 Jan 2024 14:18:17 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2D6B4224EE; Thu, 4 Jan 2024 14:17:46 +0000 (UTC) X-Original-To: linux-ext4@vger.kernel.org Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 52A7B22F17; Thu, 4 Jan 2024 14:17:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.174]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4T5TDV4s9HzWlTS; Thu, 4 Jan 2024 22:16:58 +0800 (CST) Received: from dggpeml500021.china.huawei.com (unknown [7.185.36.21]) by mail.maildlp.com (Postfix) with ESMTPS id 201D3140416; Thu, 4 Jan 2024 22:17:41 +0800 (CST) Received: from huawei.com (10.175.127.227) by dggpeml500021.china.huawei.com (7.185.36.21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Thu, 4 Jan 2024 22:17:40 +0800 From: Baokun Li To: CC: , , , , , , , , , Wei Chen , xingwei lee , Subject: [PATCH v3 1/8] ext4: fix double-free of blocks due to wrong extents moved_len Date: Thu, 4 Jan 2024 22:20:33 +0800 Message-ID: <20240104142040.2835097-2-libaokun1@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20240104142040.2835097-1-libaokun1@huawei.com> References: <20240104142040.2835097-1-libaokun1@huawei.com> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpeml500021.china.huawei.com (7.185.36.21) In ext4_move_extents(), moved_len is only updated when all moves are successfully executed, and only discards orig_inode and donor_inode preallocations when moved_len is not zero. When the loop fails to exit after successfully moving some extents, moved_len is not updated and remains at 0, so it does not discard the preallocations. If the moved extents overlap with the preallocated extents, the overlapped extents are freed twice in ext4_mb_release_inode_pa() and ext4_process_freed_data() (as described in commit 94d7c16cbbbd ("ext4: Fix double-free of blocks with EXT4_IOC_MOVE_EXT")), and bb_free is incremented twice. Hence when trim is executed, a zero-division bug is triggered in mb_update_avg_fragment_size() because bb_free is not zero and bb_fragments is zero. Therefore, update move_len after each extent move to avoid the issue. Reported-by: Wei Chen Reported-by: xingwei lee Closes: https://lore.kernel.org/r/CAO4mrferzqBUnCag8R3m2zf897ts9UEuhjFQGPtODT92rYyR2Q@mail.gmail.com Fixes: fcf6b1b729bc ("ext4: refactor ext4_move_extents code base") CC: stable@vger.kernel.org # 3.18 Signed-off-by: Baokun Li Reviewed-by: Jan Kara --- fs/ext4/move_extent.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index 3aa57376d9c2..391efa6d4c56 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -618,6 +618,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk, goto out; o_end = o_start + len; + *moved_len = 0; while (o_start < o_end) { struct ext4_extent *ex; ext4_lblk_t cur_blk, next_blk; @@ -672,7 +673,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk, */ ext4_double_up_write_data_sem(orig_inode, donor_inode); /* Swap original branches with new branches */ - move_extent_per_page(o_filp, donor_inode, + *moved_len += move_extent_per_page(o_filp, donor_inode, orig_page_index, donor_page_index, offset_in_page, cur_len, unwritten, &ret); @@ -682,9 +683,6 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk, o_start += cur_len; d_start += cur_len; } - *moved_len = o_start - orig_blk; - if (*moved_len > len) - *moved_len = len; out: if (*moved_len) {