From patchwork Fri Feb 26 14:52:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 387898 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=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 AA937C433E0 for ; Fri, 26 Feb 2021 14:56:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6A31C64EBA for ; Fri, 26 Feb 2021 14:56:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230095AbhBZOzo (ORCPT ); Fri, 26 Feb 2021 09:55:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:52634 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229947AbhBZOzn (ORCPT ); Fri, 26 Feb 2021 09:55:43 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id D8B1264EED; Fri, 26 Feb 2021 14:55:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614351303; bh=kQ2E8LRIVngf7MiN1WL7eb4nbx+M5mChP1eoPKWYmNU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c3Yz1Hm3ldU/gxEBbeR1xe5tCSAR14AoMmJGgdQRGYD2FVM2j/7wEuwyfVD4Q8jxz fzpmq/bww/aH8EgkWIjrM+NusGPfbsz5g4ljUHqlIlCfD4HnIN7bDneFBIP8l6WTBx hQZ3989jCjEVWhsMKr9dAX9R5jFLXgsvEA/fJ5aeZ10JpKmTzxT8P8+o6sXLrH/V2n m8EaGA1jooG+XMxAENrSa9kHholgPLIspHpYuhIcxqrgHPRkL3SWWHPrALP4VB99pN rAvGzBUFZZFBh++JmGrO8PayqO3O+YiOoFnoFKE10m3hLxR8kzjEBIK6qhOaDFc83N 62FtyESaZfQbg== Received: from johan by xi.lan with local (Exim 4.93.0.4) (envelope-from ) id 1lFeWZ-0000K4-G5; Fri, 26 Feb 2021 15:55:23 +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 2/2] gpio: fix gpio-device list corruption Date: Fri, 26 Feb 2021 15:52:46 +0100 Message-Id: <20210226145246.1171-3-johan@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210226145246.1171-1-johan@kernel.org> References: <20210226145246.1171-1-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 Signed-off-by: Johan Hovold Reviewed-by: Saravana Kannan --- drivers/gpio/gpiolib.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index e1016bc8cf14..42bdc55a15f9 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);