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 B8083CA0ED0 for ; Mon, 11 Sep 2023 22:09:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357867AbjIKWGk (ORCPT ); Mon, 11 Sep 2023 18:06:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35862 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239835AbjIKOaB (ORCPT ); Mon, 11 Sep 2023 10:30:01 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75798F0 for ; Mon, 11 Sep 2023 07:29:57 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9C7DC433C7; Mon, 11 Sep 2023 14:29:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694442597; bh=3bL5SEGdIm33bdeR9cv8ESqwUKrdY0qcDhdYnvGvMcQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fqB7wDOsv3X1XcewPr9CCYHbhPQYSFd3E6FN8tIySjG28htNCLuF5mVVqo9QR/coC PMAkm2n5l9/bsp8JplA4RZbwUuMq3lCPYM7NQ8h2g6SsrMrN45byhM+ullz3RdVFWF DBAdOjmi0B6mJtM5UOlInHaZLSeLGUtIBSSEeqp8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bartosz Golaszewski , Linus Walleij , Sasha Levin Subject: [PATCH 6.4 080/737] gpiolib: fix reference leaks when removing GPIO chips still in use Date: Mon, 11 Sep 2023 15:38:59 +0200 Message-ID: <20230911134652.746505575@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230911134650.286315610@linuxfoundation.org> References: <20230911134650.286315610@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bartosz Golaszewski [ Upstream commit 3386fb86ecdef0d39ee3306aea8ec290e61b934f ] After we remove a GPIO chip that still has some requested descriptors, gpiod_free_commit() will fail and we will never put the references to the GPIO device and the owning module in gpiod_free(). Rework this function to: - not warn on desc == NULL as this is a use-case on which most free functions silently return - put the references to desc->gdev and desc->gdev->owner unconditionally so that the release callback actually gets called when the remaining references are dropped by external GPIO users Signed-off-by: Bartosz Golaszewski Reviewed-by: Linus Walleij Signed-off-by: Sasha Levin --- drivers/gpio/gpiolib.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 5be8ad61523eb..6e7701f80929f 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2175,12 +2175,18 @@ static bool gpiod_free_commit(struct gpio_desc *desc) void gpiod_free(struct gpio_desc *desc) { - if (desc && desc->gdev && gpiod_free_commit(desc)) { - module_put(desc->gdev->owner); - gpio_device_put(desc->gdev); - } else { + /* + * We must not use VALIDATE_DESC_VOID() as the underlying gdev->chip + * may already be NULL but we still want to put the references. + */ + if (!desc) + return; + + if (!gpiod_free_commit(desc)) WARN_ON(extra_checks); - } + + module_put(desc->gdev->owner); + gpio_device_put(desc->gdev); } /** -- 2.40.1