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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 BBDF9C3F2D4 for ; Fri, 6 Mar 2020 07:10:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 97E9720848 for ; Fri, 6 Mar 2020 07:10:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726108AbgCFHKv (ORCPT ); Fri, 6 Mar 2020 02:10:51 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:36158 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725927AbgCFHKu (ORCPT ); Fri, 6 Mar 2020 02:10:50 -0500 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 52BDAEF5ED8D67856FF8 for ; Fri, 6 Mar 2020 15:10:47 +0800 (CST) Received: from [127.0.0.1] (10.57.101.250) by DGGEMS405-HUB.china.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.439.0; Fri, 6 Mar 2020 15:10:40 +0800 Subject: Re: [PATCH] bus: hisi_lpc: Fixup IO ports addresses to avoid use-after-free in host removal To: John Garry References: <1579200514-184352-1-git-send-email-john.garry@huawei.com> CC: , From: Wei Xu Message-ID: <5E61F770.2040101@hisilicon.com> Date: Fri, 6 Mar 2020 15:10:40 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <1579200514-184352-1-git-send-email-john.garry@huawei.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.57.101.250] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi John, On 2020/1/17 2:48, John Garry wrote: > Some released ACPI FW for Huawei boards describes incorrect the port IO > address range for child devices, in that it tells us the IO port max range > is 0x3fff for each child device, which is not correct. The address range > should be [e4:e8) or similar. With this incorrect upper range, the child > device IO port resources overlap. > > As such, the kernel thinks that the LPC host serial device is a child of > the IPMI device: > > root@(none)$ more /proc/ioports > [...] > 00ffc0e3-00ffffff : hisi-lpc-ipmi.0.auto > 00ffc0e3-00ffc0e3 : ipmi_si > 00ffc0e4-00ffc0e4 : ipmi_si > 00ffc0e5-00ffc0e5 : ipmi_si > 00ffc2f7-00ffffff : serial8250.1.auto > 00ffc2f7-00ffc2fe : serial > root@(none)$ > > They should both be siblings. Note that these are logical PIO addresses, > which have a direct mapping from the FW IO port ranges. > > This shows up as a real issue when we enable CONFIG_KASAN and > CONFIG_DEBUG_TEST_DRIVER_REMOVE - we see use-after-free warnings in the > host removal path: > > ================================================================== > BUG: KASAN: use-after-free in release_resource+0x38/0xc8 > Read of size 8 at addr ffff0026accdbc38 by task swapper/0/1 > > CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.5.0-rc6-00001-g68e186e77b5c-dirty #1593 > Hardware name: Huawei Taishan 2180 /D03, BIOS Hisilicon D03 IT20 Nemo 2.0 RC0 03/30/2018 > Call trace: > dump_backtrace+0x0/0x290 > show_stack+0x14/0x20 > dump_stack+0xf0/0x14c > print_address_description.isra.9+0x6c/0x3b8 > __kasan_report+0x12c/0x23c > kasan_report+0xc/0x18 > __asan_load8+0x94/0xb8 > release_resource+0x38/0xc8 > platform_device_del.part.10+0x80/0xe0 > platform_device_unregister+0x20/0x38 > hisi_lpc_acpi_remove_subdev+0x10/0x20 > device_for_each_child+0xc8/0x128 > hisi_lpc_acpi_remove+0x4c/0xa8 > hisi_lpc_remove+0xbc/0xc0 > platform_drv_remove+0x3c/0x68 > really_probe+0x174/0x548 > driver_probe_device+0x7c/0x148 > device_driver_attach+0x94/0xa0 > __driver_attach+0xa4/0x110 > bus_for_each_dev+0xe8/0x158 > driver_attach+0x30/0x40 > bus_add_driver+0x234/0x2f0 > driver_register+0xbc/0x1d0 > __platform_driver_register+0x7c/0x88 > hisi_lpc_driver_init+0x18/0x20 > do_one_initcall+0xb4/0x258 > kernel_init_freeable+0x248/0x2c0 > kernel_init+0x10/0x118 > ret_from_fork+0x10/0x1c > > ... > > The issue here is that the kernel created an incorrect parent-child > resource dependency between two devices, and references the false parent > node when deleting the second child device, when it had been deleted > already. > > Fix up the child device resources from FW to create proper IO port > resource relationships for broken FW. > > With this, the IO port layout looks more healthy: > > root@(none)$ more /proc/ioports > [...] > 00ffc0e3-00ffc0e7 : hisi-lpc-ipmi.0.auto > 00ffc0e3-00ffc0e3 : ipmi_si > 00ffc0e4-00ffc0e4 : ipmi_si > 00ffc0e5-00ffc0e5 : ipmi_si > 00ffc2f7-00ffc2ff : serial8250.1.auto > 00ffc2f7-00ffc2fe : serial > > Signed-off-by: John Garry Thanks! Applied to the hisilicon arm64 driver tree. Best Regards, Wei > > diff --git a/drivers/bus/hisi_lpc.c b/drivers/bus/hisi_lpc.c > index 8101df901830..08543579eefd 100644 > --- a/drivers/bus/hisi_lpc.c > +++ b/drivers/bus/hisi_lpc.c > @@ -357,6 +357,26 @@ static int hisi_lpc_acpi_xlat_io_res(struct acpi_device *adev, > return 0; > } > > +/* > + * Released firmware describes the IO port max address as 0x3fff, which is > + * the max host bus address. Fixup to a proper range. This will probably > + * never be fixed in firmware. > + */ > +static void hisi_lpc_acpi_fixup_child_resource(struct device *hostdev, > + struct resource *r) > +{ > + if (r->end != 0x3fff) > + return; > + > + if (r->start == 0xe4) > + r->end = 0xe4 + 0x04 - 1; > + else if (r->start == 0x2f8) > + r->end = 0x2f8 + 0x08 - 1; > + else > + dev_warn(hostdev, "unrecognised resource %pR to fixup, ignoring\n", > + r); > +} > + > /* > * hisi_lpc_acpi_set_io_res - set the resources for a child > * @child: the device node to be updated the I/O resource > @@ -418,8 +438,11 @@ static int hisi_lpc_acpi_set_io_res(struct device *child, > return -ENOMEM; > } > count = 0; > - list_for_each_entry(rentry, &resource_list, node) > - resources[count++] = *rentry->res; > + list_for_each_entry(rentry, &resource_list, node) { > + resources[count] = *rentry->res; > + hisi_lpc_acpi_fixup_child_resource(hostdev, &resources[count]); > + count++; > + } > > acpi_dev_free_resource_list(&resource_list); > >