From patchwork Mon Mar 1 09:05:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 390616 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 945AFC4332B for ; Mon, 1 Mar 2021 09:06:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B94464E41 for ; Mon, 1 Mar 2021 09:06:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233711AbhCAJGM (ORCPT ); Mon, 1 Mar 2021 04:06:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:38060 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233703AbhCAJFt (ORCPT ); Mon, 1 Mar 2021 04:05:49 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8369864E01; Mon, 1 Mar 2021 09:05:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614589508; bh=MZS+vEFMJfhOIBzq9iXKTlDqzsIfvu2g36hJM0R+3u8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nSPNlYQIJ5RPGN2tOwO2XcDRcIq7qsYe6seUFzMl+43ZPfLHt5Qs8Zc9NIAxa3Sd0 iSeYwM68ZDad+/L1fkJK18PKcNSjr4r03oXhCSQUCzHRRvkFj747loFrXKiG15TM7n Uq15eSvrljHoiGg5+S7NwhFv8GnwYAstkMqQQN453h2R3lCbsKOgUKZQbJxhGBpS3W yCa36EtVJWTzSzwPz7lOidmb5usLs6W1Ln4Q2Z8XZOHQ3D3i1aC6x6en6V+lJW5r1a jpjTwj4RlUlFUKriVtfDjoQQ/eem2gW+hSvkG1zf+R0StEC2+CHXnpo9zvpl2PA9IS MmsxXcyg16c7g== Received: from johan by xi.lan with local (Exim 4.93.0.4) (envelope-from ) id 1lGeUY-0006pL-8h; Mon, 01 Mar 2021 10:05:26 +0100 From: Johan Hovold To: Linus Walleij , Bartosz Golaszewski Cc: Greg Kroah-Hartman , Saravana Kannan , linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , stable@vger.kernel.org Subject: [PATCH v2 2/2] gpio: fix gpio-device list corruption Date: Mon, 1 Mar 2021 10:05:19 +0100 Message-Id: <20210301090519.26192-3-johan@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210301090519.26192-1-johan@kernel.org> References: <20210301090519.26192-1-johan@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Make sure to hold the gpio_lock when removing the gpio device from the gpio_devices list (when dropping the last reference) to avoid corrupting the list when there are concurrent accesses. Fixes: ff2b13592299 ("gpio: make the gpiochip a real device") Cc: stable@vger.kernel.org # 4.6 Reviewed-by: Saravana Kannan Signed-off-by: Johan Hovold Reviewed-by: Linus Walleij --- drivers/gpio/gpiolib.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 6e0572515d02..4253837f870b 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -475,8 +475,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); static void gpiodevice_release(struct device *dev) { struct gpio_device *gdev = container_of(dev, struct gpio_device, dev); + unsigned long flags; + spin_lock_irqsave(&gpio_lock, flags); list_del(&gdev->list); + spin_unlock_irqrestore(&gpio_lock, flags); + ida_free(&gpio_ida, gdev->id); kfree_const(gdev->label); kfree(gdev->descs);