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=-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=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 AE95FC433B4 for ; Tue, 6 Apr 2021 13:46:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 82217613C7 for ; Tue, 6 Apr 2021 13:46:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244157AbhDFNqQ (ORCPT ); Tue, 6 Apr 2021 09:46:16 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:15140 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233242AbhDFNqP (ORCPT ); Tue, 6 Apr 2021 09:46:15 -0400 Received: from DGGEMS403-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4FF7yd2RS8zpVMg; Tue, 6 Apr 2021 21:43:21 +0800 (CST) Received: from huawei.com (10.175.103.91) by DGGEMS403-HUB.china.huawei.com (10.3.19.203) with Microsoft SMTP Server id 14.3.498.0; Tue, 6 Apr 2021 21:46:02 +0800 From: Yang Yingliang To: , CC: , Subject: [PATCH -next] media: i2c: tda1997: Fix possible use-after-free in tda1997x_remove() Date: Tue, 6 Apr 2021 21:49:45 +0800 Message-ID: <20210406134945.2149969-1-yangyingliang@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.103.91] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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/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 a09bf0a39d05..89bb7e6dc7a4 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); -- 2.25.1