From nobody Thu Dec 18 11:28:42 2025 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 00FA3C0032E for ; Fri, 20 Oct 2023 21:10:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231948AbjJTVKh (ORCPT ); Fri, 20 Oct 2023 17:10:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230212AbjJTVK0 (ORCPT ); Fri, 20 Oct 2023 17:10:26 -0400 Received: from mout.gmx.net (mout.gmx.net [212.227.15.15]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 132BFD60; Fri, 20 Oct 2023 14:10:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.de; s=s31663417; t=1697836211; x=1698441011; i=w_armin@gmx.de; bh=5+KayTNVHXGBHiTso+VMux4gCfCpCNVmo/W6eOPMdjY=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:In-Reply-To: References; b=PVeR2YEU4YQ2DzZ5aj45SHhXxFIvxxBf2FjI6WmYG4KRWIFIo1gavGSEwqr2M0Q/ CDCrFXoU9PWeQUdIARqKi06jM/iEF1l+QJcsY6z3mjuH0ni61tfWTGIpORPAXrHI1 qjeM+yDO/nD5Wt8CtRvV896yuxGOc7L20DfBv71Bu6E0asnTihkLVCSJcUIE/uP5Y dm3k5LF9tXVtMXyqmbsWM5njsbGJ4dXwtXeezRZwoqRxJjDLzVU6nhEHpIkLUZYTP 1LFbHSZR6Ns/mLKlGbYE1JG3cO3Tjq36xORlll5swJnDCe/VQLZ2rysR2Wrr43Xns Pj7dICCwDjGNhxabmA== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from mx-amd-b650.users.agdsn.de ([141.30.226.129]) by mail.gmx.net (mrgmx005 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MacSe-1rUeM52uiI-00c5sO; Fri, 20 Oct 2023 23:10:11 +0200 From: Armin Wolf To: hdegoede@redhat.com, ilpo.jarvinen@linux.intel.com, markgross@kernel.org Cc: platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/5] platform/x86: wmi: Fix refcounting of WMI devices in legacy functions Date: Fri, 20 Oct 2023 23:10:02 +0200 Message-Id: <20231020211005.38216-3-W_Armin@gmx.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231020211005.38216-1-W_Armin@gmx.de> References: <20231020211005.38216-1-W_Armin@gmx.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:6t9SJmwYpBTxg5P1YT0TNeoGsgs7G90fLTolst6l4r4oJ86DkOc oonmB62FL0dpPcefsz2CageY6GpCnUudplq3pd4vtnMfmzoCydPZELsekH2Y0fLg+mn0L6T 8T0y67Eo+BmxsGjzNKxdfSujh0oiTsd6AsMssuONyQ3tscZnmtnAYREoX5EuHYgynKRB8PS vqV0ENaWzLQ7NaK4vtg2w== UI-OutboundReport: notjunk:1;M01:P0:7aSV8AgSRcc=;yT4C6ANUKCKF5/5krY2EANKw5up IE+5iuvTy2iLkJKl1DpyLlnUjHMf5G7mssO+oLslwJfrRUs4BLX36I2I7WKVYi3qburUj9kjr bdymva/CyuQboOpqjH/qQmFH2i/iEG2rnWBNvt/gdn4DJaaNKUXQhM0PED3IeNOCazUA0nGhJ VpPj1vtpy65BVlwjAlRhmzuP8HO7J95A9BoeU4Z7qjO9lcMCAHJpQufbSm4Qh8229YFtCOYZP qgyUzTeDg+FlSjzesmijy/ZvyHAICIHvvIyKH2APRiac9gtmF1rU+kpMKnZ3WIznroZ1LOOqh 8WyKbCF/7qfTVudvXKEl5ke/Hf91UwPy8u4dM/wpgANIjBLZUkeiFPEVW7mWv+sDEefZe97Ej TReMmho/ZkwGiVnLwF1/bdnHHi62ZY4gPH4/pCbmQzeVsJD96goEVS8yfCcFERbyLklc4KRwD lg4z2lIpygVBett4NrjY2dn+yv+K64sifj4shz6Hr84SxgfUhPCSdgctCR+uca4NTvvVRN72n nwmAD8R4rI46c/gsX7iE+6q+AoWAGD4DkYuPbenNDwAX4sJbIjlbSuJI3KYJSLd7LSB+VOwts Rx9/mBgMlBTuIBmhLJ9pHH9p2iWCY2O4LK4IOw0Jt0CQqBDtjBrreb8r2IcPQv7QByjKfnFDd Xy6sD2ZxBvw91MPsjr6OA5/XlyA5UklcWIXW9kxhgwDO64MVU7ZNfyiDCZgcl/wefsyGr8FaE NkVzDZsgUoJl997uTzGkrHkYSjXkwrUJCIDvZUlMFl6viUizwlax3+4mCZZ4oAbKBGTMVEGgf kzNXkEks1obfpq7qluJ6o4uMYQeyBb6V45ApY38+4KmpxLLUVdr/8NJ2Q7oDWjjldDN56dLPU 4wkORqwHTamKBLuEO5P+LYxLf2Ptop9tQ2UQiHKWWY8gDtzNMQ+MuusU4UIp7/xz/KUaVnm14 Z5a2EifHyDRa8qQOfXk0l2d1fWg= Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Until now, legacy GUID-based functions where using find_guid() when searching for WMI devices, which did no refcounting on the returned WMI device. This meant that the WMI device could disappear at any moment, potentially leading to various errors. Fix this by using bus_find_device() which returns an actual reference to the found WMI device. Signed-off-by: Armin Wolf --- drivers/platform/x86/wmi.c | 167 ++++++++++++++++++++++++------------- 1 file changed, 107 insertions(+), 60 deletions(-) diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c index 1dbef16acdeb..e3984801883a 100644 --- a/drivers/platform/x86/wmi.c +++ b/drivers/platform/x86/wmi.c @@ -109,33 +109,13 @@ static const char * const allow_duplicates[] =3D { NULL }; +#define dev_to_wblock(__dev) container_of_const(__dev, struct wmi_block, d= ev.dev) +#define dev_to_wdev(__dev) container_of_const(__dev, struct wmi_device, de= v) + /* * GUID parsing functions */ -static acpi_status find_guid(const char *guid_string, struct wmi_block **o= ut) -{ - guid_t guid_input; - struct wmi_block *wblock; - - if (!guid_string) - return AE_BAD_PARAMETER; - - if (guid_parse(guid_string, &guid_input)) - return AE_BAD_PARAMETER; - - list_for_each_entry(wblock, &wmi_block_list, list) { - if (guid_equal(&wblock->gblock.guid, &guid_input)) { - if (out) - *out =3D wblock; - - return AE_OK; - } - } - - return AE_NOT_FOUND; -} - static bool guid_parse_and_compare(const char *string, const guid_t *guid) { guid_t guid_input; @@ -245,6 +225,41 @@ static acpi_status get_event_data(const struct wmi_blo= ck *wblock, struct acpi_bu return acpi_evaluate_object(wblock->acpi_device->handle, "_WED", &input, = out); } +static int wmidev_match_guid(struct device *dev, const void *data) +{ + struct wmi_block *wblock =3D dev_to_wblock(dev); + const guid_t *guid =3D data; + + if (guid_equal(guid, &wblock->gblock.guid)) + return 1; + + return 0; +} + +static struct bus_type wmi_bus_type; + +static struct wmi_device *wmi_find_device_by_guid(const char *guid_string) +{ + struct device *dev; + guid_t guid; + int ret; + + ret =3D guid_parse(guid_string, &guid); + if (ret < 0) + return ERR_PTR(ret); + + dev =3D bus_find_device(&wmi_bus_type, NULL, &guid, wmidev_match_guid); + if (!dev) + return ERR_PTR(-ENODEV); + + return dev_to_wdev(dev); +} + +static void wmi_device_put(struct wmi_device *wdev) +{ + put_device(&wdev->dev); +} + /* * Exported WMI functions */ @@ -279,18 +294,17 @@ EXPORT_SYMBOL_GPL(set_required_buffer_size); */ int wmi_instance_count(const char *guid_string) { - struct wmi_block *wblock; - acpi_status status; + struct wmi_device *wdev; + int ret; - status =3D find_guid(guid_string, &wblock); - if (ACPI_FAILURE(status)) { - if (status =3D=3D AE_BAD_PARAMETER) - return -EINVAL; + wdev =3D wmi_find_device_by_guid(guid_string); + if (IS_ERR(wdev)) + return PTR_ERR(wdev); - return -ENODEV; - } + ret =3D wmidev_instance_count(wdev); + wmi_device_put(wdev); - return wmidev_instance_count(&wblock->dev); + return ret; } EXPORT_SYMBOL_GPL(wmi_instance_count); @@ -325,15 +339,18 @@ EXPORT_SYMBOL_GPL(wmidev_instance_count); acpi_status wmi_evaluate_method(const char *guid_string, u8 instance, u32 = method_id, const struct acpi_buffer *in, struct acpi_buffer *out) { - struct wmi_block *wblock =3D NULL; + struct wmi_device *wdev; acpi_status status; - status =3D find_guid(guid_string, &wblock); - if (ACPI_FAILURE(status)) - return status; + wdev =3D wmi_find_device_by_guid(guid_string); + if (IS_ERR(wdev)) + return AE_ERROR; + + status =3D wmidev_evaluate_method(wdev, instance, method_id, in, out); - return wmidev_evaluate_method(&wblock->dev, instance, method_id, - in, out); + wmi_device_put(wdev); + + return status; } EXPORT_SYMBOL_GPL(wmi_evaluate_method); @@ -472,13 +489,19 @@ acpi_status wmi_query_block(const char *guid_string, = u8 instance, struct acpi_buffer *out) { struct wmi_block *wblock; + struct wmi_device *wdev; acpi_status status; - status =3D find_guid(guid_string, &wblock); - if (ACPI_FAILURE(status)) - return status; + wdev =3D wmi_find_device_by_guid(guid_string); + if (IS_ERR(wdev)) + return AE_ERROR; - return __query_block(wblock, instance, out); + wblock =3D container_of(wdev, struct wmi_block, dev); + status =3D __query_block(wblock, instance, out); + + wmi_device_put(wdev); + + return status; } EXPORT_SYMBOL_GPL(wmi_query_block); @@ -516,8 +539,9 @@ EXPORT_SYMBOL_GPL(wmidev_block_query); acpi_status wmi_set_block(const char *guid_string, u8 instance, const struct acpi_buffer *in) { - struct wmi_block *wblock =3D NULL; + struct wmi_block *wblock; struct guid_block *block; + struct wmi_device *wdev; acpi_handle handle; struct acpi_object_list input; union acpi_object params[2]; @@ -527,19 +551,26 @@ acpi_status wmi_set_block(const char *guid_string, u8= instance, if (!in) return AE_BAD_DATA; - status =3D find_guid(guid_string, &wblock); - if (ACPI_FAILURE(status)) - return status; + wdev =3D wmi_find_device_by_guid(guid_string); + if (IS_ERR(wdev)) + return AE_ERROR; + wblock =3D container_of(wdev, struct wmi_block, dev); block =3D &wblock->gblock; handle =3D wblock->acpi_device->handle; - if (block->instance_count <=3D instance) - return AE_BAD_PARAMETER; + if (block->instance_count <=3D instance) { + status =3D AE_BAD_PARAMETER; + + goto err_wdev_put; + } /* Check GUID is a data block */ - if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD)) - return AE_ERROR; + if (block->flags & (ACPI_WMI_EVENT | ACPI_WMI_METHOD)) { + status =3D AE_ERROR; + + goto err_wdev_put; + } input.count =3D 2; input.pointer =3D params; @@ -551,7 +582,12 @@ acpi_status wmi_set_block(const char *guid_string, u8 = instance, get_acpi_method_name(wblock, 'S', method); - return acpi_evaluate_object(handle, method, &input, NULL); + status =3D acpi_evaluate_object(handle, method, &input, NULL); + +err_wdev_put: + wmi_device_put(wdev); + + return status; } EXPORT_SYMBOL_GPL(wmi_set_block); @@ -742,7 +778,15 @@ EXPORT_SYMBOL_GPL(wmi_get_event_data); */ bool wmi_has_guid(const char *guid_string) { - return ACPI_SUCCESS(find_guid(guid_string, NULL)); + struct wmi_device *wdev; + + wdev =3D wmi_find_device_by_guid(guid_string); + if (IS_ERR(wdev)) + return false; + + wmi_device_put(wdev); + + return true; } EXPORT_SYMBOL_GPL(wmi_has_guid); @@ -756,20 +800,23 @@ EXPORT_SYMBOL_GPL(wmi_has_guid); */ char *wmi_get_acpi_device_uid(const char *guid_string) { - struct wmi_block *wblock =3D NULL; - acpi_status status; + struct wmi_block *wblock; + struct wmi_device *wdev; + char *uid; - status =3D find_guid(guid_string, &wblock); - if (ACPI_FAILURE(status)) + wdev =3D wmi_find_device_by_guid(guid_string); + if (IS_ERR(wdev)) return NULL; - return acpi_device_uid(wblock->acpi_device); + wblock =3D container_of(wdev, struct wmi_block, dev); + uid =3D acpi_device_uid(wblock->acpi_device); + + wmi_device_put(wdev); + + return uid; } EXPORT_SYMBOL_GPL(wmi_get_acpi_device_uid); -#define dev_to_wblock(__dev) container_of_const(__dev, struct wmi_block, d= ev.dev) -#define dev_to_wdev(__dev) container_of_const(__dev, struct wmi_device, de= v) - static inline struct wmi_driver *drv_to_wdrv(struct device_driver *drv) { return container_of(drv, struct wmi_driver, driver); -- 2.39.2