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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 B2231C282C8 for ; Mon, 28 Jan 2019 15:46:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 824B82147A for ; Mon, 28 Jan 2019 15:46:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548690369; bh=RxptdGV+4lXa+UrJ0V0gXU2CCI3yBbOLulbz1uCUKWk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=inqY/aPsGeuEl6FdWl7DsKn4wu84OpNIasLHbktmOjDwhrHDJzx8knxQeuYxnOn5v Xoa4CKYJNFBI+uO9bMCoPXcf8LgkrsDRB8zlAVEcml7fcu1xckrxcyWtsbmjzHfVDC dKj336WH3d7vn/rlHnn1kCvUC6GMsOpWPBn9kGXE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727946AbfA1PqI (ORCPT ); Mon, 28 Jan 2019 10:46:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:59440 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727105AbfA1PqC (ORCPT ); Mon, 28 Jan 2019 10:46:02 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B01CF2177E; Mon, 28 Jan 2019 15:45:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548690361; bh=RxptdGV+4lXa+UrJ0V0gXU2CCI3yBbOLulbz1uCUKWk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fQQ/s8UZLB7i0a6drN72Y+p/e/ayMVIKFAs3rxbUs0Xk5QzaLs0XV0KqO/meUuT0k VNqQ1ti2xb59IlVLLKHRItmcveXl8lL3EH/McLEWjdEvfLzio6by6VB/aZkNqwpPXq 4xmkbav9xDumtaK/mMTyz2qsKycUy7J9tZIEEqrQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Akinobu Mita , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin , linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 4.20 064/304] media: video-i2c: avoid accessing released memory area when removing driver Date: Mon, 28 Jan 2019 10:39:41 -0500 Message-Id: <20190128154341.47195-64-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190128154341.47195-1-sashal@kernel.org> References: <20190128154341.47195-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Akinobu Mita [ Upstream commit c764da98a600a4b068d25c77164f092f159cecec ] The video device release() callback for video-i2c driver frees the whole struct video_i2c_data. If there is no user left for the video device when video_unregister_device() is called, the release callback is executed. However, in video_i2c_remove() some fields (v4l2_dev, lock, and queue_lock) in struct video_i2c_data are still accessed after video_unregister_device() is called. This fixes the use after free by moving the code from video_i2c_remove() to the release() callback. Fixes: 5cebaac60974 ("media: video-i2c: add video-i2c driver") Reviewed-by: Matt Ranostay Signed-off-by: Akinobu Mita Acked-by: Sakari Ailus Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/i2c/video-i2c.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c index 4d49af86c15e..ec0758dca2fc 100644 --- a/drivers/media/i2c/video-i2c.c +++ b/drivers/media/i2c/video-i2c.c @@ -510,7 +510,12 @@ static const struct v4l2_ioctl_ops video_i2c_ioctl_ops = { static void video_i2c_release(struct video_device *vdev) { - kfree(video_get_drvdata(vdev)); + struct video_i2c_data *data = video_get_drvdata(vdev); + + v4l2_device_unregister(&data->v4l2_dev); + mutex_destroy(&data->lock); + mutex_destroy(&data->queue_lock); + kfree(data); } static int video_i2c_probe(struct i2c_client *client, @@ -608,10 +613,6 @@ static int video_i2c_remove(struct i2c_client *client) struct video_i2c_data *data = i2c_get_clientdata(client); video_unregister_device(&data->vdev); - v4l2_device_unregister(&data->v4l2_dev); - - mutex_destroy(&data->lock); - mutex_destroy(&data->queue_lock); return 0; } -- 2.19.1