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 X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,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 48B7CC468BD for ; Sun, 9 Jun 2019 17:00:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 186BE206DF for ; Sun, 9 Jun 2019 17:00:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560099609; bh=9PYpEDZLRhbi7YVmJolHM37nqF9o+1KmaP4pr3hYhsM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=s0BaVc4DcuLx7nhAvw/SXAEYRIYzcVFUokVcQi0uBuxVyqJgXk6/s8kj7GkCSR/zm nS0TOPNsSLOiTKmE3QhvkEKzG5SQJ3IuT3wI08AibykG5bYQjZUfgBiJKO1mTdZxMq /lUBZwjL5QBW06nf1sKbNQrSqkpADi/e7Yax5lOU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387787AbfFIRAI (ORCPT ); Sun, 9 Jun 2019 13:00:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:36280 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387774AbfFIRAD (ORCPT ); Sun, 9 Jun 2019 13:00:03 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B424E2084A; Sun, 9 Jun 2019 17:00:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560099603; bh=9PYpEDZLRhbi7YVmJolHM37nqF9o+1KmaP4pr3hYhsM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D3OmlFJpP2nyM0J6STJWEBVwtur54yqypjwP6pDwP9EIULiJj6fM7M64vDceT5pLL qTAHnE4j+XZqHiVgE6V2GMYkuB39rt7rbmoGCkcRyZs+yt8Df/lULWxq9wmq0wWuyW +JBPfrSio+8V7XWpHcPCslmd/buMIX2MVBiYa5dc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sven Van Asbroeck , Alexandre Belloni , Sasha Levin Subject: [PATCH 4.4 100/241] rtc: 88pm860x: prevent use-after-free on device remove Date: Sun, 9 Jun 2019 18:40:42 +0200 Message-Id: <20190609164150.681387111@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190609164147.729157653@linuxfoundation.org> References: <20190609164147.729157653@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit f22b1ba15ee5785aa028384ebf77dd39e8e47b70 ] The device's remove() attempts to shut down the delayed_work scheduled on the kernel-global workqueue by calling flush_scheduled_work(). Unfortunately, flush_scheduled_work() does not prevent the delayed_work from re-scheduling itself. The delayed_work might run after the device has been removed, and touch the already de-allocated info structure. This is a potential use-after-free. Fix by calling cancel_delayed_work_sync() during remove(): this ensures that the delayed work is properly cancelled, is no longer running, and is not able to re-schedule itself. This issue was detected with the help of Coccinelle. Signed-off-by: Sven Van Asbroeck Signed-off-by: Alexandre Belloni Signed-off-by: Sasha Levin --- drivers/rtc/rtc-88pm860x.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-88pm860x.c b/drivers/rtc/rtc-88pm860x.c index 19e53b3b8e005..166faae3a59cd 100644 --- a/drivers/rtc/rtc-88pm860x.c +++ b/drivers/rtc/rtc-88pm860x.c @@ -414,7 +414,7 @@ static int pm860x_rtc_remove(struct platform_device *pdev) struct pm860x_rtc_info *info = platform_get_drvdata(pdev); #ifdef VRTC_CALIBRATION - flush_scheduled_work(); + cancel_delayed_work_sync(&info->calib_work); /* disable measurement */ pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); #endif /* VRTC_CALIBRATION */ -- 2.20.1