From patchwork Tue Apr 6 13:50:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yang Yingliang X-Patchwork-Id: 12185335 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=-16.8 required=3.0 tests=BAYES_00, 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 DAACCC433B4 for ; Tue, 6 Apr 2021 13:47:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A3E7C613C3 for ; Tue, 6 Apr 2021 13:47:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238299AbhDFNrX (ORCPT ); Tue, 6 Apr 2021 09:47:23 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:16365 "EHLO szxga07-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233167AbhDFNrW (ORCPT ); Tue, 6 Apr 2021 09:47:22 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4FF80Y1pgwz9wjL; Tue, 6 Apr 2021 21:45:01 +0800 (CST) Received: from huawei.com (10.175.103.91) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.498.0; Tue, 6 Apr 2021 21:47:10 +0800 From: Yang Yingliang To: , CC: , Subject: [PATCH -next] media: i2c: adv7842: fix possible use-after-free in adv7842_remove() Date: Tue, 6 Apr 2021 21:50:53 +0800 Message-ID: <20210406135053.2150439-1-yangyingliang@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.175.103.91] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org 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 --- 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 21dbb7a594fb..8bd58ce07926 100644 --- a/drivers/media/i2c/adv7842.c +++ b/drivers/media/i2c/adv7842.c @@ -3573,7 +3573,7 @@ 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);