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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 BB4C7C282C3 for ; Thu, 24 Jan 2019 19:54:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 87F0F21726 for ; Thu, 24 Jan 2019 19:54:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548359664; bh=jAH+6IhrDcnlx5EmBeFbvnsWo2oqJG5NFYBLEFHoYCQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gE6pwK8kpCb4LH1cZrkvHtPBS65xKc9SU+vdhgdzecAdIv4lqsdtM/CxUT6GHzynb mRYpwCl7YfuZYywlaB08mhCx+5Uxpkc3EQDB+xYPRpJWoyvHxq0VxvbXSoB8hg/yLR bCtHQZNNRHQgOJN4aasM+Ez0GenGaiOZKLC5sRQk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732637AbfAXTh3 (ORCPT ); Thu, 24 Jan 2019 14:37:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:37504 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732650AbfAXTh1 (ORCPT ); Thu, 24 Jan 2019 14:37:27 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (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 2D996218FC; Thu, 24 Jan 2019 19:37:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548358646; bh=jAH+6IhrDcnlx5EmBeFbvnsWo2oqJG5NFYBLEFHoYCQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FnlJN4L1DRk7tjxjxmOYKKSzDeSO9KPZSg1hvhTNJ7lwJSdrWBbOWsT+sELcSJhTq hARYQN1vZYNq65p93tkLOf8THfoBis8GlfF32d7TOf72Vpb74u/gpNRUmcBBAAgpLN GPX0em7SreEB7ZaOTP4BMaO+v6YBrEF2Py5BA30w= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Javier Barrio , Jan Kara , Sasha Levin Subject: [PATCH 4.19 082/106] quota: Lock s_umount in exclusive mode for Q_XQUOTA{ON,OFF} quotactls. Date: Thu, 24 Jan 2019 20:20:39 +0100 Message-Id: <20190124190211.372983736@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190124190206.342411005@linuxfoundation.org> References: <20190124190206.342411005@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 41c4f85cdac280d356df1f483000ecec4a8868be ] Commit 1fa5efe3622db58cb8c7b9a50665e9eb9a6c7e97 (ext4: Use generic helpers for quotaon and quotaoff) made possible to call quotactl(Q_XQUOTAON/OFF) on ext4 filesystems with sysfile quota support. This leads to calling dquot_enable/disable without s_umount held in excl. mode, because quotactl_cmd_onoff checks only for Q_QUOTAON/OFF. The following WARN_ON_ONCE triggers (in this case for dquot_enable, ext4, latest Linus' tree): [ 117.807056] EXT4-fs (dm-0): mounted filesystem with ordered data mode. Opts: quota,prjquota [...] [ 155.036847] WARNING: CPU: 0 PID: 2343 at fs/quota/dquot.c:2469 dquot_enable+0x34/0xb9 [ 155.036851] Modules linked in: quota_v2 quota_tree ipv6 af_packet joydev mousedev psmouse serio_raw pcspkr i2c_piix4 intel_agp intel_gtt e1000 ttm drm_kms_helper drm agpgart fb_sys_fops syscopyarea sysfillrect sysimgblt i2c_core input_leds kvm_intel kvm irqbypass qemu_fw_cfg floppy evdev parport_pc parport button crc32c_generic dm_mod ata_generic pata_acpi ata_piix libata loop ext4 crc16 mbcache jbd2 usb_storage usbcore sd_mod scsi_mod [ 155.036901] CPU: 0 PID: 2343 Comm: qctl Not tainted 4.20.0-rc6-00025-gf5d582777bcb #9 [ 155.036903] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [ 155.036911] RIP: 0010:dquot_enable+0x34/0xb9 [ 155.036915] Code: 41 56 41 55 41 54 55 53 4c 8b 6f 28 74 02 0f 0b 4d 8d 7d 70 49 89 fc 89 cb 41 89 d6 89 f5 4c 89 ff e8 23 09 ea ff 85 c0 74 0a <0f> 0b 4c 89 ff e8 8b 09 ea ff 85 db 74 6a 41 8b b5 f8 00 00 00 0f [ 155.036918] RSP: 0018:ffffb09b00493e08 EFLAGS: 00010202 [ 155.036922] RAX: 0000000000000001 RBX: 0000000000000008 RCX: 0000000000000008 [ 155.036924] RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff9781b67cd870 [ 155.036926] RBP: 0000000000000002 R08: 0000000000000000 R09: 61c8864680b583eb [ 155.036929] R10: ffffb09b00493e48 R11: ffffffffff7ce7d4 R12: ffff9781b7ee8d78 [ 155.036932] R13: ffff9781b67cd800 R14: 0000000000000004 R15: ffff9781b67cd870 [ 155.036936] FS: 00007fd813250b88(0000) GS:ffff9781ba000000(0000) knlGS:0000000000000000 [ 155.036939] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 155.036942] CR2: 00007fd812ff61d6 CR3: 000000007c882000 CR4: 00000000000006b0 [ 155.036951] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 155.036953] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 155.036955] Call Trace: [ 155.037004] dquot_quota_enable+0x8b/0xd0 [ 155.037011] kernel_quotactl+0x628/0x74e [ 155.037027] ? do_mprotect_pkey+0x2a6/0x2cd [ 155.037034] __x64_sys_quotactl+0x1a/0x1d [ 155.037041] do_syscall_64+0x55/0xe4 [ 155.037078] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 155.037105] RIP: 0033:0x7fd812fe1198 [ 155.037109] Code: 02 77 0d 48 89 c1 48 c1 e9 3f 75 04 48 8b 04 24 48 83 c4 50 5b c3 48 83 ec 08 49 89 ca 48 63 d2 48 63 ff b8 b3 00 00 00 0f 05 <48> 89 c7 e8 c1 eb ff ff 5a c3 48 63 ff b8 bb 00 00 00 0f 05 48 89 [ 155.037112] RSP: 002b:00007ffe8cd7b050 EFLAGS: 00000206 ORIG_RAX: 00000000000000b3 [ 155.037116] RAX: ffffffffffffffda RBX: 00007ffe8cd7b148 RCX: 00007fd812fe1198 [ 155.037119] RDX: 0000000000000000 RSI: 00007ffe8cd7cea9 RDI: 0000000000580102 [ 155.037121] RBP: 00007ffe8cd7b0f0 R08: 000055fc8eba8a9d R09: 0000000000000000 [ 155.037124] R10: 00007ffe8cd7b074 R11: 0000000000000206 R12: 00007ffe8cd7b168 [ 155.037126] R13: 000055fc8eba8897 R14: 0000000000000000 R15: 0000000000000000 [ 155.037131] ---[ end trace 210f864257175c51 ]--- and then the syscall proceeds without s_umount locking. This patch locks the superblock ->s_umount sem. in exclusive mode for all Q_XQUOTAON/OFF quotactls too in addition to Q_QUOTAON/OFF. AFAICT, other than ext4, only xfs and ocfs2 are affected by this change. The VFS will now call in xfs_quota_* functions with s_umount held, which wasn't the case before. This looks good to me but I can not say for sure. Ext4 and ocfs2 where already beeing called with s_umount exclusive via quota_quotaon/off which is basically the same. Signed-off-by: Javier Barrio Signed-off-by: Jan Kara Signed-off-by: Sasha Levin --- fs/quota/quota.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/quota/quota.c b/fs/quota/quota.c index f0cbf58ad4da..fd5dd806f1b9 100644 --- a/fs/quota/quota.c +++ b/fs/quota/quota.c @@ -791,7 +791,8 @@ static int quotactl_cmd_write(int cmd) /* Return true if quotactl command is manipulating quota on/off state */ static bool quotactl_cmd_onoff(int cmd) { - return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF); + return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF) || + (cmd == Q_XQUOTAON) || (cmd == Q_XQUOTAOFF); } /* -- 2.19.1