From patchwork Mon May 10 10:20:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 434075 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=-19.4 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 67DA3C433B4 for ; Mon, 10 May 2021 10:35:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3229F61993 for ; Mon, 10 May 2021 10:35:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231557AbhEJKgl (ORCPT ); Mon, 10 May 2021 06:36:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:41148 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231244AbhEJKeK (ORCPT ); Mon, 10 May 2021 06:34:10 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7205661582; Mon, 10 May 2021 10:27:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620642472; bh=4KlBC0WUa0ro5p4CMyIxeEkz8qtxpYGBJcTcLS8FXA0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OjYFUbRrkudD4USWdV+3dwRQgyM22mCwHWoTbhuxW4EGbxE4wrmNR/XhlO+im6Yfk aR5rTO53BTM8PaOP7F/J+GmwqNDul12az/u4dfg6l8lJz0GFf4aoRMvv/G6YGZ87nH 0IJZjoIXd/mHf2V50oBnFmXMyUt7xvpLyXQ51ndU= 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 5.4 108/184] media: i2c: tda1997: Fix possible use-after-free in tda1997x_remove() Date: Mon, 10 May 2021 12:20:02 +0200 Message-Id: <20210510101953.730186051@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210510101950.200777181@linuxfoundation.org> References: <20210510101950.200777181@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 7f820ab5d4eebfe2d970d32a76ae496a6c286f0f ] 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/tda1997x.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/i2c/tda1997x.c b/drivers/media/i2c/tda1997x.c index 5e68182001ec..e43d8327b810 100644 --- a/drivers/media/i2c/tda1997x.c +++ b/drivers/media/i2c/tda1997x.c @@ -2804,7 +2804,7 @@ static int tda1997x_remove(struct i2c_client *client) media_entity_cleanup(&sd->entity); v4l2_ctrl_handler_free(&state->hdl); regulator_bulk_disable(TDA1997X_NUM_SUPPLIES, state->supplies); - cancel_delayed_work(&state->delayed_work_enable_hpd); + cancel_delayed_work_sync(&state->delayed_work_enable_hpd); mutex_destroy(&state->page_lock); mutex_destroy(&state->lock);