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 0694BC74A44 for ; Fri, 10 Mar 2023 14:01:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231423AbjCJOB3 (ORCPT ); Fri, 10 Mar 2023 09:01:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231491AbjCJOBY (ORCPT ); Fri, 10 Mar 2023 09:01:24 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03180114EE4 for ; Fri, 10 Mar 2023 06:01:17 -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 ams.source.kernel.org (Postfix) with ESMTPS id A2599B822B1 for ; Fri, 10 Mar 2023 14:01:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6AB1C433EF; Fri, 10 Mar 2023 14:01:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678456874; bh=mdXaVsMHHRpVXUk+uZ9EYwJv98Vwf3VmgKDN7QRilxw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jCwJ9am9S3xObZriBUm7kGyG/8LHyn9Q78Ki+sVzmErGlMgao+cq6KTn+2pLOWzYE cwm0axiHDctBl5cFKk0KI7zu2XugHlfpT2KVuO/l7dUuJW+VBP6BtOgzpP/ZWHyxX9 8exHSmXApr9eV3pHdJb55UG2TPqexN3rN1e7bfoo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paulo Miguel Almeida , Dan Carpenter , Sidong Yang , Liu Shixin , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Sasha Levin Subject: [PATCH 6.2 155/211] staging: pi433: fix memory leak with using debugfs_lookup() Date: Fri, 10 Mar 2023 14:38:55 +0100 Message-Id: <20230310133723.461567484@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230310133718.689332661@linuxfoundation.org> References: <20230310133718.689332661@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: Greg Kroah-Hartman [ Upstream commit 2f36e789e540df6a9fbf471b3a2ba62a8b361586 ] When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. This requires saving off the root directory dentry to make creation of individual device subdirectories easier. Cc: Paulo Miguel Almeida Cc: Dan Carpenter Cc: Sidong Yang Cc: Liu Shixin Cc: "Uwe Kleine-König" Link: https://lore.kernel.org/r/20230202141138.2291946-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/staging/pi433/pi433_if.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/staging/pi433/pi433_if.c b/drivers/staging/pi433/pi433_if.c index d4e06a3929f3d..b59f6a4cb611a 100644 --- a/drivers/staging/pi433/pi433_if.c +++ b/drivers/staging/pi433/pi433_if.c @@ -55,6 +55,7 @@ static dev_t pi433_dev; static DEFINE_IDR(pi433_idr); static DEFINE_MUTEX(minor_lock); /* Protect idr accesses */ +static struct dentry *root_dir; /* debugfs root directory for the driver */ static struct class *pi433_class; /* mainly for udev to create /dev/pi433 */ @@ -1306,8 +1307,7 @@ static int pi433_probe(struct spi_device *spi) /* spi setup */ spi_set_drvdata(spi, device); - entry = debugfs_create_dir(dev_name(device->dev), - debugfs_lookup(KBUILD_MODNAME, NULL)); + entry = debugfs_create_dir(dev_name(device->dev), root_dir); debugfs_create_file("regs", 0400, entry, device, &pi433_debugfs_regs_fops); return 0; @@ -1333,9 +1333,8 @@ static int pi433_probe(struct spi_device *spi) static void pi433_remove(struct spi_device *spi) { struct pi433_device *device = spi_get_drvdata(spi); - struct dentry *mod_entry = debugfs_lookup(KBUILD_MODNAME, NULL); - debugfs_remove(debugfs_lookup(dev_name(device->dev), mod_entry)); + debugfs_lookup_and_remove(dev_name(device->dev), root_dir); /* free GPIOs */ free_gpio(device); @@ -1408,7 +1407,7 @@ static int __init pi433_init(void) return PTR_ERR(pi433_class); } - debugfs_create_dir(KBUILD_MODNAME, NULL); + root_dir = debugfs_create_dir(KBUILD_MODNAME, NULL); status = spi_register_driver(&pi433_spi_driver); if (status < 0) { @@ -1427,7 +1426,7 @@ static void __exit pi433_exit(void) spi_unregister_driver(&pi433_spi_driver); class_destroy(pi433_class); unregister_chrdev(MAJOR(pi433_dev), pi433_spi_driver.driver.name); - debugfs_remove_recursive(debugfs_lookup(KBUILD_MODNAME, NULL)); + debugfs_remove(root_dir); } module_exit(pi433_exit); -- 2.39.2