From patchwork Tue Apr 6 13:39:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yang Yingliang X-Patchwork-Id: 417075 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 8774BC433B4 for ; Tue, 6 Apr 2021 13:35:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 57BED613B7 for ; Tue, 6 Apr 2021 13:35:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237177AbhDFNgA (ORCPT ); Tue, 6 Apr 2021 09:36:00 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:15615 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233339AbhDFNf7 (ORCPT ); Tue, 6 Apr 2021 09:35:59 -0400 Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4FF7lR2Hvdz19Kp5; Tue, 6 Apr 2021 21:33:39 +0800 (CST) Received: from huawei.com (10.175.103.91) by DGGEMS408-HUB.china.huawei.com (10.3.19.208) with Microsoft SMTP Server id 14.3.498.0; Tue, 6 Apr 2021 21:35:45 +0800 From: Yang Yingliang To: , CC: , Subject: [PATCH -next] media: tc358743: fix possible use-after-free in tc358743_remove() Date: Tue, 6 Apr 2021 21:39:29 +0800 Message-ID: <20210406133929.2143249-1-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/tc358743.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/i2c/tc358743.c b/drivers/media/i2c/tc358743.c index 831b5b54fd78..1b309bb743c7 100644 --- a/drivers/media/i2c/tc358743.c +++ b/drivers/media/i2c/tc358743.c @@ -2193,7 +2193,7 @@ static int tc358743_remove(struct i2c_client *client) del_timer_sync(&state->timer); flush_work(&state->work_i2c_poll); } - cancel_delayed_work(&state->delayed_work_enable_hotplug); + cancel_delayed_work_sync(&state->delayed_work_enable_hotplug); cec_unregister_adapter(state->cec_adap); v4l2_async_unregister_subdev(sd); v4l2_device_unregister_subdev(sd);