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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 A021EC282CE for ; Wed, 22 May 2019 19:46:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 69A3120856 for ; Wed, 22 May 2019 19:46:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558554397; bh=kY6nnKcNmJPO49Acu53z4ErLu6Vs+4a1pFHpsxCrX80=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HoLqtqmrSTVZBN7pwoykENdaC9yVX42UvnNvcWi7JKLc7x0gSvbDpeTBjIf6kLUZx d8rKWuzLu/vMFysSBN47RD+NpuQhhadmeLNQq/z1kJM1mn/pXyKpXdihc3bYRwm+XX SP4TItG8LtuwBpFlgtQX53tHFHwa+n/9+oOpWzn8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732832AbfEVTqg (ORCPT ); Wed, 22 May 2019 15:46:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:50210 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731844AbfEVT1s (ORCPT ); Wed, 22 May 2019 15:27:48 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 48395217F9; Wed, 22 May 2019 19:27:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558553268; bh=kY6nnKcNmJPO49Acu53z4ErLu6Vs+4a1pFHpsxCrX80=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MJmioQ084t7SwHH0HlON3MHamWSVLDcm477Kn54ZH4DUAB5dQxRK8Z27jQ4ew23Q0 jTxxP47Lp7QISXCKN1j/ebMtjekX3FJvkU/WKert74T2qdXkrfTVMaug/Ye/zLmBci BXEFNKnDKMrNSPnj0D06Iz6EMKYf50NPXrbErusM= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sven Van Asbroeck , Sven Van Asbroeck , Alexandre Belloni , Sasha Levin , linux-rtc@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 044/244] rtc: 88pm860x: prevent use-after-free on device remove Date: Wed, 22 May 2019 15:23:10 -0400 Message-Id: <20190522192630.24917-44-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190522192630.24917-1-sashal@kernel.org> References: <20190522192630.24917-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sven Van Asbroeck [ 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 01ffc0ef8033f..fbcf13bbbd8d1 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