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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 24C44C54EBE for ; Mon, 16 Jan 2023 17:07:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234235AbjAPRHg (ORCPT ); Mon, 16 Jan 2023 12:07:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33386 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230272AbjAPRHB (ORCPT ); Mon, 16 Jan 2023 12:07:01 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 632F83A86F for ; Mon, 16 Jan 2023 08:47:58 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8297D61084 for ; Mon, 16 Jan 2023 16:47:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95B21C433D2; Mon, 16 Jan 2023 16:47:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673887670; bh=cu8Tc4ulYpC6xsu1UaAG0/QGhYAdc9Fc6yxXzGH5ILI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fBWEu8E6+JUpbuGj3n+Nu8khqSJ1Sc5PEzIkKTi6akbIsDLPzkLF8UIbKJCJoOvbw b63HX15yoz4fZroquTA4sI7QZg+5lanF3qs6+9TS7xZTVaRaH+MRwucz7aFXdNgyEh N+iaFcRk1YdfQI2gjmWCPDmKkY326NP5PE4gK9lA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lee Jones , Andrzej Pietrasiewicz , John Keeping , Sasha Levin Subject: [PATCH 4.19 238/521] usb: gadget: f_hid: fix f_hidg lifetime vs cdev Date: Mon, 16 Jan 2023 16:48:20 +0100 Message-Id: <20230116154857.773901805@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230116154847.246743274@linuxfoundation.org> References: <20230116154847.246743274@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: John Keeping [ Upstream commit 89ff3dfac604614287ad5aad9370c3f984ea3f4b ] The embedded struct cdev does not have its lifetime correctly tied to the enclosing struct f_hidg, so there is a use-after-free if /dev/hidgN is held open while the gadget is deleted. This can readily be replicated with libusbgx's example programs (for conciseness - operating directly via configfs is equivalent): gadget-hid exec 3<> /dev/hidg0 gadget-vid-pid-remove exec 3<&- Pull the existing device up in to struct f_hidg and make use of the cdev_device_{add,del}() helpers. This changes the lifetime of the device object to match struct f_hidg, but note that it is still added and deleted at the same time. Fixes: 71adf1189469 ("USB: gadget: add HID gadget driver") Tested-by: Lee Jones Reviewed-by: Andrzej Pietrasiewicz Reviewed-by: Lee Jones Signed-off-by: John Keeping Link: https://lore.kernel.org/r/20221122123523.3068034-2-john@metanate.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/gadget/function/f_hid.c | 52 ++++++++++++++++------------- 1 file changed, 28 insertions(+), 24 deletions(-) diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c index 0c200f152036..2aaa3ea74e5a 100644 --- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -71,7 +71,7 @@ struct f_hidg { wait_queue_head_t write_queue; struct usb_request *req; - int minor; + struct device dev; struct cdev cdev; struct usb_function func; @@ -84,6 +84,14 @@ static inline struct f_hidg *func_to_hidg(struct usb_function *f) return container_of(f, struct f_hidg, func); } +static void hidg_release(struct device *dev) +{ + struct f_hidg *hidg = container_of(dev, struct f_hidg, dev); + + kfree(hidg->set_report_buf); + kfree(hidg); +} + /*-------------------------------------------------------------------------*/ /* Static descriptors */ @@ -910,9 +918,7 @@ static int hidg_bind(struct usb_configuration *c, struct usb_function *f) struct usb_ep *ep; struct f_hidg *hidg = func_to_hidg(f); struct usb_string *us; - struct device *device; int status; - dev_t dev; /* maybe allocate device-global string IDs, and patch descriptors */ us = usb_gstrings_attach(c->cdev, ct_func_strings, @@ -1005,21 +1011,11 @@ static int hidg_bind(struct usb_configuration *c, struct usb_function *f) /* create char device */ cdev_init(&hidg->cdev, &f_hidg_fops); - dev = MKDEV(major, hidg->minor); - status = cdev_add(&hidg->cdev, dev, 1); + status = cdev_device_add(&hidg->cdev, &hidg->dev); if (status) goto fail_free_descs; - device = device_create(hidg_class, NULL, dev, NULL, - "%s%d", "hidg", hidg->minor); - if (IS_ERR(device)) { - status = PTR_ERR(device); - goto del; - } - return 0; -del: - cdev_del(&hidg->cdev); fail_free_descs: usb_free_all_descriptors(f); fail: @@ -1250,9 +1246,7 @@ static void hidg_free(struct usb_function *f) hidg = func_to_hidg(f); opts = container_of(f->fi, struct f_hid_opts, func_inst); - kfree(hidg->report_desc); - kfree(hidg->set_report_buf); - kfree(hidg); + put_device(&hidg->dev); mutex_lock(&opts->lock); --opts->refcnt; mutex_unlock(&opts->lock); @@ -1262,8 +1256,7 @@ static void hidg_unbind(struct usb_configuration *c, struct usb_function *f) { struct f_hidg *hidg = func_to_hidg(f); - device_destroy(hidg_class, MKDEV(major, hidg->minor)); - cdev_del(&hidg->cdev); + cdev_device_del(&hidg->cdev, &hidg->dev); usb_free_all_descriptors(f); } @@ -1272,6 +1265,7 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi) { struct f_hidg *hidg; struct f_hid_opts *opts; + int ret; /* allocate and initialize one new instance */ hidg = kzalloc(sizeof(*hidg), GFP_KERNEL); @@ -1283,17 +1277,27 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi) mutex_lock(&opts->lock); ++opts->refcnt; - hidg->minor = opts->minor; + device_initialize(&hidg->dev); + hidg->dev.release = hidg_release; + hidg->dev.class = hidg_class; + hidg->dev.devt = MKDEV(major, opts->minor); + ret = dev_set_name(&hidg->dev, "hidg%d", opts->minor); + if (ret) { + --opts->refcnt; + mutex_unlock(&opts->lock); + return ERR_PTR(ret); + } + hidg->bInterfaceSubClass = opts->subclass; hidg->bInterfaceProtocol = opts->protocol; hidg->report_length = opts->report_length; hidg->report_desc_length = opts->report_desc_length; if (opts->report_desc) { - hidg->report_desc = kmemdup(opts->report_desc, - opts->report_desc_length, - GFP_KERNEL); + hidg->report_desc = devm_kmemdup(&hidg->dev, opts->report_desc, + opts->report_desc_length, + GFP_KERNEL); if (!hidg->report_desc) { - kfree(hidg); + put_device(&hidg->dev); mutex_unlock(&opts->lock); return ERR_PTR(-ENOMEM); } -- 2.35.1