From patchwork Tue Mar 8 17:18:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakob Koschel X-Patchwork-Id: 549645 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 E1717C433FE for ; Tue, 8 Mar 2022 17:20:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244081AbiCHRVL (ORCPT ); Tue, 8 Mar 2022 12:21:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348986AbiCHRUh (ORCPT ); Tue, 8 Mar 2022 12:20:37 -0500 Received: from mail-ej1-x62c.google.com (mail-ej1-x62c.google.com [IPv6:2a00:1450:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 766E253B68; Tue, 8 Mar 2022 09:19:30 -0800 (PST) Received: by mail-ej1-x62c.google.com with SMTP id yy13so31927368ejb.2; Tue, 08 Mar 2022 09:19:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=fephKwqGahaE5ePrpyTUfZ7vzKqhC09iEtMfdAncdNM=; b=bRM/OMuDGEv0AZGOOzGCmNCsSpySNqu07Hft34oEc9A6ak9XMmK+29xqpHDV97GpvA 6zbYVmumIsOBgZnKtMh6+nvYaWqVcsUUWykf2ErUi5J6RWqEYk5ALbCHPcgq3K9dM25m cDhwwdMGrtjPdIWCfavmaPo2986IKJvS1y1Bg4OTJML9wNk7hnOF2hf+Zy55CQHZGnMi WOWCMvczodHmb4pi1JqtcqWldbpEJIUiFXKBZsOXYBbKVehmE+5GjDvhFXB2+3bL0z0C O4XG2LrZZ17yMk4WfeRr1QGFuct9eYkq0XdaIUzNsdLmjDhbyFOg7wkjUakFPNNOzmje 520w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=fephKwqGahaE5ePrpyTUfZ7vzKqhC09iEtMfdAncdNM=; b=5/Wkr7fESjE9VSpIM61L2GEyQn5z4hg5sjAn0mTut5hprYvs1GkDOfQCMEt9Pnz+cP B1o5qOLi1CL7GYcafAJWGUDYkww9irNIov9/+YKKhnyhJ5ISJl6l92ixMlqEP9ku//rf WIysA9+/Tc1QURkIyg80oVYiBHpf0QrVTGUAZskK8hgGf0M0DyTBJplKCKOtMaOKIeDU AEJNjbsAIedDNkOWF2sZ7JpahakpRGar7F796NVaUbQzZvMK25pHkMee+Q3LDiC0lNp5 HpJgh+MN+eaTkM7eYBV2uGpCAbiUzCbc8n41uEAsZZ0GTAxEHNSXWOIbDmfDQbTbuaxd Ds3w== X-Gm-Message-State: AOAM532okICEXspmjRJg7Md8uVa1lULR5i3iCnzR4G3Ws+VIxVzGKRHu vdrMGMrK4zOrF0cIDtzWmlY= X-Google-Smtp-Source: ABdhPJxByY5nw9jmtNB7IUcf/8bjjy7qzOQPkkkPtk4UKkjYZWHA8u51uU9OkIsMOffHmN06pgZUag== X-Received: by 2002:a17:907:961b:b0:6d9:acb0:5403 with SMTP id gb27-20020a170907961b00b006d9acb05403mr14001239ejc.568.1646759968956; Tue, 08 Mar 2022 09:19:28 -0800 (PST) Received: from localhost.localdomain (i130160.upc-i.chello.nl. [62.195.130.160]) by smtp.googlemail.com with ESMTPSA id rv11-20020a17090710cb00b006d5c0cd5e0dsm6085044ejb.82.2022.03.08.09.19.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Mar 2022 09:19:28 -0800 (PST) From: Jakob Koschel To: Greg Kroah-Hartman Cc: Jakob Koschel , linux-kernel@vger.kernel.org, Linus Torvalds , Felipe Balbi , Joel Stanley , Andrew Jeffery , Nicolas Ferre , Alexandre Belloni , Claudiu Beznea , Cristian Birsan , Al Cooper , Li Yang , Vladimir Zapolskiy , Daniel Mack , Haojian Zhuang , Robert Jarzmik , Krzysztof Kozlowski , Alim Akhtar , Thierry Reding , Jonathan Hunter , Michal Simek , linux-usb@vger.kernel.org (open list:USB GADGET/PERIPHERAL SUBSYSTEM), Mike Rapoport , "Brian Johannesmeyer" , Cristiano Giuffrida , "Bos, H.J." Subject: [PATCH v2 18/26] usb: gadget: legacy: remove using list iterator after loop body as a ptr Date: Tue, 8 Mar 2022 18:18:10 +0100 Message-Id: <20220308171818.384491-19-jakobkoschel@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220308171818.384491-1-jakobkoschel@gmail.com> References: <20220308171818.384491-1-jakobkoschel@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org If the list does not contain the expected element, the value of list_for_each_entry() iterator will not point to a valid structure. To avoid type confusion in such case, the list iterator scope will be limited to list_for_each_entry() loop. In preparation to limiting scope of a list iterator to the list traversal loop, use a dedicated pointer to point to the found element [1]. Determining if an element was found is then simply checking if the pointer is != NULL instead of using the potentially bogus pointer. Link: https://lore.kernel.org/all/YhdfEIwI4EdtHdym@kroah.com/ Signed-off-by: Jakob Koschel --- drivers/usb/gadget/legacy/hid.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/drivers/usb/gadget/legacy/hid.c b/drivers/usb/gadget/legacy/hid.c index 3912cc805f3a..1187ee4f316a 100644 --- a/drivers/usb/gadget/legacy/hid.c +++ b/drivers/usb/gadget/legacy/hid.c @@ -134,7 +134,7 @@ static int hid_bind(struct usb_composite_dev *cdev) { struct usb_gadget *gadget = cdev->gadget; struct list_head *tmp; - struct hidg_func_node *n, *m; + struct hidg_func_node *n = NULL, *m, *iter_n; struct f_hid_opts *hid_opts; int status, funcs = 0; @@ -144,18 +144,19 @@ static int hid_bind(struct usb_composite_dev *cdev) if (!funcs) return -ENODEV; - list_for_each_entry(n, &hidg_func_list, node) { - n->fi = usb_get_function_instance("hid"); - if (IS_ERR(n->fi)) { - status = PTR_ERR(n->fi); + list_for_each_entry(iter_n, &hidg_func_list, node) { + iter_n->fi = usb_get_function_instance("hid"); + if (IS_ERR(iter_n->fi)) { + status = PTR_ERR(iter_n->fi); + n = iter_n; goto put; } - hid_opts = container_of(n->fi, struct f_hid_opts, func_inst); - hid_opts->subclass = n->func->subclass; - hid_opts->protocol = n->func->protocol; - hid_opts->report_length = n->func->report_length; - hid_opts->report_desc_length = n->func->report_desc_length; - hid_opts->report_desc = n->func->report_desc; + hid_opts = container_of(iter_n->fi, struct f_hid_opts, func_inst); + hid_opts->subclass = iter_n->func->subclass; + hid_opts->protocol = iter_n->func->protocol; + hid_opts->report_length = iter_n->func->report_length; + hid_opts->report_desc_length = iter_n->func->report_desc_length; + hid_opts->report_desc = iter_n->func->report_desc; }