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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 8AB11C2D0BE for ; Sun, 8 Dec 2019 13:56:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6AB43206F4 for ; Sun, 8 Dec 2019 13:56:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726818AbfLHN44 (ORCPT ); Sun, 8 Dec 2019 08:56:56 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:60250 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726566AbfLHNyn (ORCPT ); Sun, 8 Dec 2019 08:54:43 -0500 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 1idx1D-0007fH-Qa; Sun, 08 Dec 2019 13:54:39 +0000 Received: from ben by deadeye with local (Exim 4.93-RC1) (envelope-from ) id 1idx1C-0002Ns-G2; Sun, 08 Dec 2019 13:54:38 +0000 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 , "Jiri Pirko" , "Zhang Rui" , "Ido Schimmel" Date: Sun, 08 Dec 2019 13:53:27 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 43/72] thermal: Fix use-after-free when unregistering thermal zone device 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: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 3.16.79-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Ido Schimmel commit 1851799e1d2978f68eea5d9dff322e121dcf59c1 upstream. thermal_zone_device_unregister() cancels the delayed work that polls the thermal zone, but it does not wait for it to finish. This is racy with respect to the freeing of the thermal zone device, which can result in a use-after-free [1]. Fix this by waiting for the delayed work to finish before freeing the thermal zone device. Note that thermal_zone_device_set_polling() is never invoked from an atomic context, so it is safe to call cancel_delayed_work_sync() that can block. [1] [ +0.002221] ================================================================== [ +0.000064] BUG: KASAN: use-after-free in __mutex_lock+0x1076/0x11c0 [ +0.000016] Read of size 8 at addr ffff8881e48e0450 by task kworker/1:0/17 [ +0.000023] CPU: 1 PID: 17 Comm: kworker/1:0 Not tainted 5.2.0-rc6-custom-02495-g8e73ca3be4af #1701 [ +0.000010] Hardware name: Mellanox Technologies Ltd. MSN2100-CB2FO/SA001017, BIOS 5.6.5 06/07/2016 [ +0.000016] Workqueue: events_freezable_power_ thermal_zone_device_check [ +0.000012] Call Trace: [ +0.000021] dump_stack+0xa9/0x10e [ +0.000020] print_address_description.cold.2+0x9/0x25e [ +0.000018] __kasan_report.cold.3+0x78/0x9d [ +0.000016] kasan_report+0xe/0x20 [ +0.000016] __mutex_lock+0x1076/0x11c0 [ +0.000014] step_wise_throttle+0x72/0x150 [ +0.000018] handle_thermal_trip+0x167/0x760 [ +0.000019] thermal_zone_device_update+0x19e/0x5f0 [ +0.000019] process_one_work+0x969/0x16f0 [ +0.000017] worker_thread+0x91/0xc40 [ +0.000014] kthread+0x33d/0x400 [ +0.000015] ret_from_fork+0x3a/0x50 [ +0.000020] Allocated by task 1: [ +0.000015] save_stack+0x19/0x80 [ +0.000015] __kasan_kmalloc.constprop.4+0xc1/0xd0 [ +0.000014] kmem_cache_alloc_trace+0x152/0x320 [ +0.000015] thermal_zone_device_register+0x1b4/0x13a0 [ +0.000015] mlxsw_thermal_init+0xc92/0x23d0 [ +0.000014] __mlxsw_core_bus_device_register+0x659/0x11b0 [ +0.000013] mlxsw_core_bus_device_register+0x3d/0x90 [ +0.000013] mlxsw_pci_probe+0x355/0x4b0 [ +0.000014] local_pci_probe+0xc3/0x150 [ +0.000013] pci_device_probe+0x280/0x410 [ +0.000013] really_probe+0x26a/0xbb0 [ +0.000013] driver_probe_device+0x208/0x2e0 [ +0.000013] device_driver_attach+0xfe/0x140 [ +0.000013] __driver_attach+0x110/0x310 [ +0.000013] bus_for_each_dev+0x14b/0x1d0 [ +0.000013] driver_register+0x1c0/0x400 [ +0.000015] mlxsw_sp_module_init+0x5d/0xd3 [ +0.000014] do_one_initcall+0x239/0x4dd [ +0.000013] kernel_init_freeable+0x42b/0x4e8 [ +0.000012] kernel_init+0x11/0x18b [ +0.000013] ret_from_fork+0x3a/0x50 [ +0.000015] Freed by task 581: [ +0.000013] save_stack+0x19/0x80 [ +0.000014] __kasan_slab_free+0x125/0x170 [ +0.000013] kfree+0xf3/0x310 [ +0.000013] thermal_release+0xc7/0xf0 [ +0.000014] device_release+0x77/0x200 [ +0.000014] kobject_put+0x1a8/0x4c0 [ +0.000014] device_unregister+0x38/0xc0 [ +0.000014] thermal_zone_device_unregister+0x54e/0x6a0 [ +0.000014] mlxsw_thermal_fini+0x184/0x35a [ +0.000014] mlxsw_core_bus_device_unregister+0x10a/0x640 [ +0.000013] mlxsw_devlink_core_bus_device_reload+0x92/0x210 [ +0.000015] devlink_nl_cmd_reload+0x113/0x1f0 [ +0.000014] genl_family_rcv_msg+0x700/0xee0 [ +0.000013] genl_rcv_msg+0xca/0x170 [ +0.000013] netlink_rcv_skb+0x137/0x3a0 [ +0.000012] genl_rcv+0x29/0x40 [ +0.000013] netlink_unicast+0x49b/0x660 [ +0.000013] netlink_sendmsg+0x755/0xc90 [ +0.000013] __sys_sendto+0x3de/0x430 [ +0.000013] __x64_sys_sendto+0xe2/0x1b0 [ +0.000013] do_syscall_64+0xa4/0x4d0 [ +0.000013] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ +0.000017] The buggy address belongs to the object at ffff8881e48e0008 which belongs to the cache kmalloc-2k of size 2048 [ +0.000012] The buggy address is located 1096 bytes inside of 2048-byte region [ffff8881e48e0008, ffff8881e48e0808) [ +0.000007] The buggy address belongs to the page: [ +0.000012] page:ffffea0007923800 refcount:1 mapcount:0 mapping:ffff88823680d0c0 index:0x0 compound_mapcount: 0 [ +0.000020] flags: 0x200000000010200(slab|head) [ +0.000019] raw: 0200000000010200 ffffea0007682008 ffffea00076ab808 ffff88823680d0c0 [ +0.000016] raw: 0000000000000000 00000000000d000d 00000001ffffffff 0000000000000000 [ +0.000007] page dumped because: kasan: bad access detected [ +0.000012] Memory state around the buggy address: [ +0.000012] ffff8881e48e0300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ +0.000012] ffff8881e48e0380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ +0.000012] >ffff8881e48e0400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ +0.000008] ^ [ +0.000012] ffff8881e48e0480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ +0.000012] ffff8881e48e0500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ +0.000007] ================================================================== Fixes: b1569e99c795 ("ACPI: move thermal trip handling to generic thermal layer") Reported-by: Jiri Pirko Signed-off-by: Ido Schimmel Acked-by: Jiri Pirko Signed-off-by: Zhang Rui Signed-off-by: Ben Hutchings --- drivers/thermal/thermal_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -333,7 +333,7 @@ static void thermal_zone_device_set_poll mod_delayed_work(system_freezable_wq, &tz->poll_queue, msecs_to_jiffies(delay)); else - cancel_delayed_work(&tz->poll_queue); + cancel_delayed_work_sync(&tz->poll_queue); } static void monitor_thermal_zone(struct thermal_zone_device *tz)