From patchwork Thu May 20 09:20:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 445424 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=-19.1 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 A3DF6C433B4 for ; Thu, 20 May 2021 10:51:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8810060FF3 for ; Thu, 20 May 2021 10:51:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239139AbhETKwV (ORCPT ); Thu, 20 May 2021 06:52:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:48280 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238827AbhETKuU (ORCPT ); Thu, 20 May 2021 06:50:20 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7322B61CC6; Thu, 20 May 2021 09:59:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621504773; bh=+fXdL/7vNmQLpNMjy3WhSp3t8ZHg4Y0vuI8idMut46Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2VsLEPLgSiY/+UVsHFBPLtVbp0xBQtrPapcyQLA9xPu7urHrmqbs7jPQxO4QX3UKT PZm1FqW0gMXU6enQQc/a96nStCTtcbh/z3PYLFBYLW0WCtpdzhoyBiEq+5nw26NvgF ywJaXt1CanduF4pmdp5OzDjIoJCN/1BcPS5Qo21s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hulk Robot , Yang Yingliang , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 4.9 041/240] media: i2c: adv7842: fix possible use-after-free in adv7842_remove() Date: Thu, 20 May 2021 11:20:33 +0200 Message-Id: <20210520092110.036817690@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092108.587553970@linuxfoundation.org> References: <20210520092108.587553970@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Yang Yingliang [ Upstream commit 4a15275b6a18597079f18241c87511406575179a ] This driver's remove path calls cancel_delayed_work(). However, that function does not wait until the work function finishes. This means that the callback function may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling cancel_delayed_work_sync(), which ensures that the work is properly cancelled, no longer running, and unable to re-schedule itself. Reported-by: Hulk Robot Signed-off-by: Yang Yingliang Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/i2c/adv7842.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/i2c/adv7842.c b/drivers/media/i2c/adv7842.c index cf3b42c9417e..d7af4fbcb84b 100644 --- a/drivers/media/i2c/adv7842.c +++ b/drivers/media/i2c/adv7842.c @@ -3598,7 +3598,7 @@ static int adv7842_remove(struct i2c_client *client) struct adv7842_state *state = to_state(sd); adv7842_irq_enable(sd, false); - cancel_delayed_work(&state->delayed_work_enable_hotplug); + cancel_delayed_work_sync(&state->delayed_work_enable_hotplug); v4l2_device_unregister_subdev(sd); media_entity_cleanup(&sd->entity); adv7842_unregister_clients(sd);