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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 74BFAC433DF for ; Tue, 9 Jun 2020 18:10:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DA5220691 for ; Tue, 9 Jun 2020 18:10:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388531AbgFISKC (ORCPT ); Tue, 9 Jun 2020 14:10:02 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41426 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388174AbgFISF7 (ORCPT ); Tue, 9 Jun 2020 14:05:59 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1jiidG-0001pF-Gf; Tue, 09 Jun 2020 19:05:54 +0100 Received: from ben by deadeye with local (Exim 4.94) (envelope-from ) id 1jiidG-006VxJ-38; Tue, 09 Jun 2020 19:05:54 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , stable@kernel.org, "Theodore Ts'o" , "Jan Kara" , "Shijie Luo" Date: Tue, 09 Jun 2020 19:04:44 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 53/61] ext4: add cond_resched() to ext4_protect_reserved_inode In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.85-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Shijie Luo commit af133ade9a40794a37104ecbcc2827c0ea373a3c upstream. When journal size is set too big by "mkfs.ext4 -J size=", or when we mount a crafted image to make journal inode->i_size too big, the loop, "while (i < num)", holds cpu too long. This could cause soft lockup. [ 529.357541] Call trace: [ 529.357551] dump_backtrace+0x0/0x198 [ 529.357555] show_stack+0x24/0x30 [ 529.357562] dump_stack+0xa4/0xcc [ 529.357568] watchdog_timer_fn+0x300/0x3e8 [ 529.357574] __hrtimer_run_queues+0x114/0x358 [ 529.357576] hrtimer_interrupt+0x104/0x2d8 [ 529.357580] arch_timer_handler_virt+0x38/0x58 [ 529.357584] handle_percpu_devid_irq+0x90/0x248 [ 529.357588] generic_handle_irq+0x34/0x50 [ 529.357590] __handle_domain_irq+0x68/0xc0 [ 529.357593] gic_handle_irq+0x6c/0x150 [ 529.357595] el1_irq+0xb8/0x140 [ 529.357599] __ll_sc_atomic_add_return_acquire+0x14/0x20 [ 529.357668] ext4_map_blocks+0x64/0x5c0 [ext4] [ 529.357693] ext4_setup_system_zone+0x330/0x458 [ext4] [ 529.357717] ext4_fill_super+0x2170/0x2ba8 [ext4] [ 529.357722] mount_bdev+0x1a8/0x1e8 [ 529.357746] ext4_mount+0x44/0x58 [ext4] [ 529.357748] mount_fs+0x50/0x170 [ 529.357752] vfs_kern_mount.part.9+0x54/0x188 [ 529.357755] do_mount+0x5ac/0xd78 [ 529.357758] ksys_mount+0x9c/0x118 [ 529.357760] __arm64_sys_mount+0x28/0x38 [ 529.357764] el0_svc_common+0x78/0x130 [ 529.357766] el0_svc_handler+0x38/0x78 [ 529.357769] el0_svc+0x8/0xc [ 541.356516] watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [mount:18674] Link: https://lore.kernel.org/r/20200211011752.29242-1-luoshijie1@huawei.com Reviewed-by: Jan Kara Signed-off-by: Shijie Luo Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Ben Hutchings --- fs/ext4/block_validity.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/ext4/block_validity.c +++ b/fs/ext4/block_validity.c @@ -153,6 +153,7 @@ static int ext4_protect_reserved_inode(s return PTR_ERR(inode); num = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits; while (i < num) { + cond_resched(); map.m_lblk = i; map.m_len = num - i; n = ext4_map_blocks(NULL, inode, &map, 0);