{"id":2196249,"url":"http://patchwork.ozlabs.org/api/1.0/patches/2196249/?format=json","project":{"id":42,"url":"http://patchwork.ozlabs.org/api/1.0/projects/42/?format=json","name":"Linux GPIO development","link_name":"linux-gpio","list_id":"linux-gpio.vger.kernel.org","list_email":"linux-gpio@vger.kernel.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20260213092958.864411-6-tzungbi@kernel.org>","date":"2026-02-13T09:29:52","name":"[v3,05/11] gpio: cdev: Don't check struct gpio_chip in gpio_chrdev_open()","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"f5217efbc6d9b178cefa528bc89f7ce59aca6cad","submitter":{"id":83557,"url":"http://patchwork.ozlabs.org/api/1.0/people/83557/?format=json","name":"Tzung-Bi Shih","email":"tzungbi@kernel.org"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linux-gpio/patch/20260213092958.864411-6-tzungbi@kernel.org/mbox/","series":[{"id":492068,"url":"http://patchwork.ozlabs.org/api/1.0/series/492068/?format=json","date":"2026-02-13T09:29:47","name":"gpio: Adopt revocable mechanism for UAF prevention","version":3,"mbox":"http://patchwork.ozlabs.org/series/492068/mbox/"}],"check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2196249/checks/","tags":{},"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-gpio@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256\n header.s=k20201202 header.b=TWrwKmsz;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=172.234.253.10; helo=sea.lore.kernel.org;\n envelope-from=linux-gpio+bounces-31662-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org\n header.b=\"TWrwKmsz\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=10.30.226.201"],"Received":["from sea.lore.kernel.org (sea.lore.kernel.org [172.234.253.10])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fC6Rj5dcFz1xvQ\n\tfor ; Fri, 13 Feb 2026 20:33:37 +1100 (AEDT)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sea.lore.kernel.org (Postfix) with ESMTP id F1B223142BAA\n\tfor ; Fri, 13 Feb 2026 09:31:18 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id AAD03330D2F;\n\tFri, 13 Feb 2026 09:31:18 +0000 (UTC)","from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org\n [10.30.226.201])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 6A83C31A044;\n\tFri, 13 Feb 2026 09:31:17 +0000 (UTC)","by smtp.kernel.org (Postfix) with ESMTPSA id F1429C19421;\n\tFri, 13 Feb 2026 09:31:14 +0000 (UTC)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1770975078; cv=none;\n b=ncsT83phnt/Sn/al26fWXx3AdfO1A1SOXAlpCctJaBJE6mm+8bqUlY67IRoQh4PDQsvdypb+Asm0RCOhMBtOQZWT1b5jyiobbtwN8Nm2MKj5XR/DNE6ufJOQJV1TBnZkCrc/poVEMUPBpAWnLHnlKkK5ce4wSK0l6dECV8pDcpI=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1770975078; c=relaxed/simple;\n\tbh=MhNx3S0dVlpNxKMRcdobUk3hHUbH0H41bs4+2RGrNYw=;\n\th=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References:\n\t MIME-Version;\n b=cOkkvWDs4B7sPL+nMTE0SnpTfPto9x2cSiqQHvds1jpe43/YL8jMdIZoMtpjZ4GJFKBVFZjosZG1iH4jjNKB3Uj6RizRIEEgpLk4emGn3gGSSLhXtpP+Z9k5Txe+69pdZjiLFxbx8YWwkkaZJdnSuyzsCAEk5gVmLaMmmPRUzSA=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org\n header.b=TWrwKmsz; arc=none smtp.client-ip=10.30.226.201","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org;\n\ts=k20201202; t=1770975077;\n\tbh=MhNx3S0dVlpNxKMRcdobUk3hHUbH0H41bs4+2RGrNYw=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=TWrwKmszBLe/Bar8C4Mt8P2JxMjERmVpyNENpy0vWefh6rLl8F/jQzCpGL/f2ff+1\n\t IbgTE7zn12xKEzb6j/gNFYRnlsVPzfuKRlhSHtgXGkOZ02XuW1TNrn7aeZw2NwdA8k\n\t 3DtJC+aJQZe3xc+Eh0f+J0N7GwDAyS8C6e0j/xg66UmERfCvRKhV+uMVRGT/XSpVKP\n\t 2SwvsbIgc6Uhp4+dg9O/RiNFUFQch2BK2FAPYxJjW8ysRtewLdUrZ+3ZoOGLOmhXmD\n\t d6MFxCEk+2pBeCVkn8/54jXpPxPjQYv7AfVD0kfFwEp6ZdvpQ9Q6zPfxUQCA4VhHyo\n\t MFsXxqxjGpH1g==","From":"Tzung-Bi Shih ","To":"Bartosz Golaszewski ,\n\tLinus Walleij ","Cc":"Greg Kroah-Hartman ,\n\t\"Rafael J. Wysocki\" ,\n\tDanilo Krummrich ,\n\tJonathan Corbet ,\n\tShuah Khan ,\n\tLaurent Pinchart ,\n\tWolfram Sang ,\n\tJason Gunthorpe ,\n\tJohan Hovold ,\n\t\"Paul E . McKenney\" ,\n\tDan Williams ,\n\tchrome-platform@lists.linux.dev,\n\ttzungbi@kernel.org,\n\tlinux-gpio@vger.kernel.org,\n\tlinux-kselftest@vger.kernel.org,\n\tlinux-kernel@vger.kernel.org","Subject":"[PATCH v3 05/11] gpio: cdev: Don't check struct gpio_chip in\n gpio_chrdev_open()","Date":"Fri, 13 Feb 2026 09:29:52 +0000","Message-ID":"<20260213092958.864411-6-tzungbi@kernel.org>","X-Mailer":"git-send-email 2.53.0.310.g728cabbaf7-goog","In-Reply-To":"<20260213092958.864411-1-tzungbi@kernel.org>","References":"<20260213092958.864411-1-tzungbi@kernel.org>","Precedence":"bulk","X-Mailing-List":"linux-gpio@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit"},"content":"It's harmless even if: chrdev_open() and cdev_device_del() run at the\nsame time, and gpio_chrdev_open() gets called after the underlying GPIO\nchip has gone. The subsequent file operations check the availability\nof struct gpio_chip anyway.\n\nDon't check struct gpio_chip in gpio_chrdev_open().\n\nSigned-off-by: Tzung-Bi Shih \n---\nv3:\n- No changes.\n\nv2: https://lore.kernel.org/all/20260203061059.975605-6-tzungbi@kernel.org\n- No changes.\n\nv1: https://lore.kernel.org/all/20260116081036.352286-11-tzungbi@kernel.org\n\n drivers/gpio/gpiolib-cdev.c | 6 ------\n 1 file changed, 6 deletions(-)","diff":"diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c\nindex b028198adba8..2e3484a89a3b 100644\n--- a/drivers/gpio/gpiolib-cdev.c\n+++ b/drivers/gpio/gpiolib-cdev.c\n@@ -2689,12 +2689,6 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)\n \tstruct gpio_chardev_data *cdev;\n \tint ret = -ENOMEM;\n \n-\tguard(srcu)(&gdev->srcu);\n-\n-\t/* Fail on open if the backing gpiochip is gone */\n-\tif (!rcu_access_pointer(gdev->chip))\n-\t\treturn -ENODEV;\n-\n \tcdev = kzalloc(sizeof(*cdev), GFP_KERNEL);\n \tif (!cdev)\n \t\treturn -ENOMEM;\n","prefixes":["v3","05/11"]}