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=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 E4E4EC282DD for ; Wed, 22 May 2019 19:36:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AE45920675 for ; Wed, 22 May 2019 19:36:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558553777; bh=Z5M97+wnGla18P25MkB3sjrGHWb2JtxK/um22vBOWNQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=bPKMC0n4UJRAkPj6qc3XvgrpG0DZ3PAxo2ib+RW9Z5avt+DGx7DT1eBYaApaT8QTy XxlfZ/v4De796p4ciiQ6xDBoLi4aNh6pAzyd3mJSjOcqQVLGERmIl6iQThRLz6/NW/ PY2eqb8ijY6hoLluFnzQ60AarhNMZ53v+m5s1jTw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387396AbfEVTau (ORCPT ); Wed, 22 May 2019 15:30:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:54254 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732913AbfEVTas (ORCPT ); Wed, 22 May 2019 15:30:48 -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 EE23921473; Wed, 22 May 2019 19:30:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558553447; bh=Z5M97+wnGla18P25MkB3sjrGHWb2JtxK/um22vBOWNQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o+cy/+wVR8Q2Tuue1s+++sEaaVpbgChfOGkTX5Zuv1bNffzgui3BaCtEIM7kE96nu FQd9jZRxZWUYB52eI2irCTR49EMJkKwZYOTrUXF4ndoMOJJOx+fPAqOrAipsdr+cI5 ZldGjhuCQqdPqKdUIg5QNwGUCj5eFjtSyBFYSKVA= 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 4.9 017/114] rtc: 88pm860x: prevent use-after-free on device remove Date: Wed, 22 May 2019 15:28:40 -0400 Message-Id: <20190522193017.26567-17-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190522193017.26567-1-sashal@kernel.org> References: <20190522193017.26567-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@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 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