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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 70B40C43141 for ; Thu, 14 Nov 2019 13:18:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4BBCD20715 for ; Thu, 14 Nov 2019 13:18:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726597AbfKNNSE (ORCPT ); Thu, 14 Nov 2019 08:18:04 -0500 Received: from foss.arm.com ([217.140.110.172]:43042 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726139AbfKNNSD (ORCPT ); Thu, 14 Nov 2019 08:18:03 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E20E731B; Thu, 14 Nov 2019 05:18:02 -0800 (PST) Received: from [192.168.0.21] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CF30B3F52E; Thu, 14 Nov 2019 05:18:00 -0800 (PST) Subject: Re: [PATCH 5.3 113/148] thermal: Fix use-after-free when unregistering thermal zone device To: Greg Kroah-Hartman , linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org, Jiri Pirko , Ido Schimmel , Zhang Rui , Sasha Levin , wvw@google.com, lukasz.luba@arm.com References: <20191010083609.660878383@linuxfoundation.org> <20191010083617.967244655@linuxfoundation.org> From: Lukasz Luba Message-ID: <905e26d4-76c7-555f-3b33-51fa3cf7a470@arm.com> Date: Thu, 14 Nov 2019 13:17:55 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191010083617.967244655@linuxfoundation.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Greg, This patch causes a deadlock, the thermal framework stops. Please check this fix (I found it before posting exactly the same solution): https://lkml.org/lkml/2019/11/12/1075 I have verified it on OdroidXU4 and it works. It needs some cleaning in the commit message, though. I have added to CC the author: Wei Wang I don't know in how many stable trees it was applied, but should be fix there also. Regards, Lukasz Luba On 10/10/19 9:36 AM, Greg Kroah-Hartman wrote: > From: Ido Schimmel > > [ Upstream commit 1851799e1d2978f68eea5d9dff322e121dcf59c1 ] > > 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: Sasha Levin > --- > drivers/thermal/thermal_core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > index 6bab66e84eb58..ebe15f2cf7fc3 100644 > --- a/drivers/thermal/thermal_core.c > +++ b/drivers/thermal/thermal_core.c > @@ -304,7 +304,7 @@ static void thermal_zone_device_set_polling(struct thermal_zone_device *tz, > &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) >