From patchwork Mon Nov 28 15:44:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Nan X-Patchwork-Id: 13057680 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1CFF2C43217 for ; Mon, 28 Nov 2022 15:23:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231674AbiK1PXf (ORCPT ); Mon, 28 Nov 2022 10:23:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60162 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231516AbiK1PXc (ORCPT ); Mon, 28 Nov 2022 10:23:32 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E34032AEE; Mon, 28 Nov 2022 07:23:31 -0800 (PST) Received: from dggpeml500025.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4NLTk36zDZzmW9G; Mon, 28 Nov 2022 23:22:51 +0800 (CST) Received: from dggpeml500003.china.huawei.com (7.185.36.200) by dggpeml500025.china.huawei.com (7.185.36.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Mon, 28 Nov 2022 23:23:30 +0800 Received: from huawei.com (10.175.127.227) by dggpeml500003.china.huawei.com (7.185.36.200) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Mon, 28 Nov 2022 23:23:29 +0800 From: Li Nan To: , , CC: , , , , , Subject: [PATCH -next 7/8] blk-iocost: fix possible UAF in ioc_pd_free Date: Mon, 28 Nov 2022 23:44:33 +0800 Message-ID: <20221128154434.4177442-8-linan122@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20221128154434.4177442-1-linan122@huawei.com> References: <20221128154434.4177442-1-linan122@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpeml500003.china.huawei.com (7.185.36.200) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Our test found the following problem in kernel 5.10, and the same problem should exist in mainline: BUG: KASAN: use-after-free in _raw_spin_lock_irqsave+0x71/0xe0 Write of size 4 at addr ffff8881432000e0 by task swapper/4/0 ... Call Trace: dump_stack+0x9c/0xd3 print_address_description.constprop.0+0x19/0x170 __kasan_report.cold+0x6c/0x84 kasan_report+0x3a/0x50 check_memory_region+0xfd/0x1f0 _raw_spin_lock_irqsave+0x71/0xe0 ioc_pd_free+0x9d/0x250 blkg_free.part.0+0x80/0x100 __blkg_release+0xf3/0x1c0 rcu_do_batch+0x292/0x700 rcu_core+0x270/0x2d0 __do_softirq+0xfd/0x402 asm_call_irq_on_stack+0x12/0x20 do_softirq_own_stack+0x37/0x50 irq_exit_rcu+0x134/0x1a0 sysvec_apic_timer_interrupt+0x36/0x80 asm_sysvec_apic_timer_interrupt+0x12/0x20 Freed by task 57: kfree+0xba/0x680 rq_qos_exit+0x5a/0x80 blk_cleanup_queue+0xce/0x1a0 virtblk_remove+0x77/0x130 [virtio_blk] virtio_dev_remove+0x56/0xe0 __device_release_driver+0x2ba/0x450 device_release_driver+0x29/0x40 bus_remove_device+0x1d8/0x2c0 device_del+0x333/0x7e0 device_unregister+0x27/0x90 unregister_virtio_device+0x22/0x40 virtio_pci_remove+0x53/0xb0 pci_device_remove+0x7a/0x130 __device_release_driver+0x2ba/0x450 device_release_driver+0x29/0x40 pci_stop_bus_device+0xcf/0x100 pci_stop_and_remove_bus_device+0x16/0x20 disable_slot+0xa1/0x110 acpiphp_disable_and_eject_slot+0x35/0xe0 hotplug_event+0x1b8/0x3c0 acpiphp_hotplug_notify+0x37/0x70 acpi_device_hotplug+0xee/0x320 acpi_hotplug_work_fn+0x69/0x80 process_one_work+0x3c5/0x730 worker_thread+0x93/0x650 kthread+0x1ba/0x210 ret_from_fork+0x22/0x30 It happened as follow: T1 T2 T3 //rmdir cgroup blkcg_destroy_blkgs blkg_destroy percpu_ref_kill blkg_release call_rcu //delete device del_gendisk rq_qos_exit ioc_rqos_exit kfree(ioc) __blkg_release blkg_free blkg_free_workfn pd_free_fn ioc_pd_free spin_lock_irqsave ->ioc is freed Fix the problem by moving the operation on ioc in ioc_pd_free() to ioc_pd_offline(), and just free resource in ioc_pd_free() like iolatency and throttle. Signed-off-by: Li Nan --- block/blk-iocost.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 03977385449f..1b855babfc35 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -2978,7 +2978,7 @@ static void ioc_pd_init(struct blkg_policy_data *pd) spin_unlock_irqrestore(&ioc->lock, flags); } -static void ioc_pd_free(struct blkg_policy_data *pd) +static void ioc_pd_offline(struct blkg_policy_data *pd) { struct ioc_gq *iocg = pd_to_iocg(pd); struct ioc *ioc = iocg->ioc; @@ -3002,6 +3002,12 @@ static void ioc_pd_free(struct blkg_policy_data *pd) hrtimer_cancel(&iocg->waitq_timer); } +} + +static void ioc_pd_free(struct blkg_policy_data *pd) +{ + struct ioc_gq *iocg = pd_to_iocg(pd); + free_percpu(iocg->pcpu_stat); kfree(iocg); } @@ -3488,6 +3494,7 @@ static struct blkcg_policy blkcg_policy_iocost = { .cpd_free_fn = ioc_cpd_free, .pd_alloc_fn = ioc_pd_alloc, .pd_init_fn = ioc_pd_init, + .pd_offline_fn = ioc_pd_offline, .pd_free_fn = ioc_pd_free, .pd_stat_fn = ioc_pd_stat, };