From patchwork Mon Mar 15 13:51:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 401552 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,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 D21F1C433E9 for ; Mon, 15 Mar 2021 13:58:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1F7864F6D for ; Mon, 15 Mar 2021 13:58:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232240AbhCON6A (ORCPT ); Mon, 15 Mar 2021 09:58:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:34938 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231964AbhCON5Y (ORCPT ); Mon, 15 Mar 2021 09:57:24 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D531964F26; Mon, 15 Mar 2021 13:57:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615816644; bh=c0d2jQS6BFUIMLZ+8dVKgguyF42abj0GKOvlSsKcxUM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eLsklG7E3ORJPQG8A+PHJBxlD36HOXWmB3noRi77qYZtdmUP8g8gl0SubW86vDr6P x0JSZEhbIYcczKP0++V5BZWotbNgire+6Wxj7rnnY2d8GO2iZDaXS16u1oKNlnhDs4 Tl0oshCTYotCTp5/sWZX8WabAD7p9Tsz7rLN6huM= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Saravana Kannan , Johan Hovold , Bartosz Golaszewski Subject: [PATCH 5.11 038/306] gpio: fix gpio-device list corruption Date: Mon, 15 Mar 2021 14:51:41 +0100 Message-Id: <20210315135508.925911883@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135507.611436477@linuxfoundation.org> References: <20210315135507.611436477@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Greg Kroah-Hartman From: Johan Hovold commit cf25ef6b631c6fc6c0435fc91eba8734cca20511 upstream. 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 Signed-off-by: Bartosz Golaszewski [ johan: adjust context to 5.11 ] Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/gpio/gpiolib.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -469,8 +469,12 @@ EXPORT_SYMBOL_GPL(gpiochip_line_is_valid static void gpiodevice_release(struct device *dev) { struct gpio_device *gdev = dev_get_drvdata(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);