From patchwork Sat Oct 20 14:26:23 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Akinobu Mita X-Patchwork-Id: 10650543 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CFA1490 for ; Sat, 20 Oct 2018 14:26:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BEE7828622 for ; Sat, 20 Oct 2018 14:26:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B280028630; Sat, 20 Oct 2018 14:26:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5A54D28622 for ; Sat, 20 Oct 2018 14:26:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727413AbeJTWhY (ORCPT ); Sat, 20 Oct 2018 18:37:24 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:34209 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727373AbeJTWhY (ORCPT ); Sat, 20 Oct 2018 18:37:24 -0400 Received: by mail-pf1-f193.google.com with SMTP id f78-v6so12039027pfe.1 for ; Sat, 20 Oct 2018 07:26:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=ed53biS0Z1WkaZmk97GMEJDJhEcCDxqfC9gtj4Eukkw=; b=UAkf5erO9j2M6Nm2//oLZ2xXvTZcxXsds+O/+OSeA3eD0xhWRAumCMarF3gPX3sm65 GhZQ0m62TFm61A7en7/lgzy9scosFPIF1saDIeKLk+M8WEoutCup4S6UFfTwZYC3b6z/ KIKkcA8ejbYc/U4g01Kg6NYekxqm93vyA6m6MCpkO/9rEmayijootHhbYGOBOr31XaTK kKR5z63kFhoRyOxylfP+SbhC6G+ODHEGmPsQnhJEOpstHhEJY7XeQwP3fdx7Rzr70ahO 7jN8IIaF5UCAHj+fxsvwCO0gbHWaBxCrfvp4Fs3NuTUPihVilBcgYxkAs2u6nqGdYc07 UR+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=ed53biS0Z1WkaZmk97GMEJDJhEcCDxqfC9gtj4Eukkw=; b=SndadUzn5PQDJhQlp5K9Zrd5QdbxM1HMqzsS24g2AsukreiWc+V0oJBf2FIsmi7WTh hBvqQB65d5wqtVON7P1FI416vsrBqy0zGfaLQdOHgXQSW4JSgzH65IjcnlMTLE1iWxw5 PHM84EceewG0noZAzjTK/CPB2r3TKlc2imMR2cu6NYEj9pxwul92M12u8AALGO+I9jaL k19SZo7FyfRXU2Ze6DhvFTJPR2awYO2T9NECG6LHycNlxUrjfk7DEb2xXI5YGfRS/J/Q 74QklyeUGHVyOpnJkuthbW/eweXzJqSrGJ+eGWGX/SKIgzYKsYMYhIdy+Blql8PV5qSn B7gw== X-Gm-Message-State: ABuFfohh+HfRZbUuw23ZCoyeZuCt49s1v47egx7uG5gNzBDWKX+tmlAc 6q4+MHNIKb5WUaiGY0Qk1wLjEZOD X-Google-Smtp-Source: ACcGV60CjOSxFjmxZdE9rzXhjje+AvvMCI7kVKkHz3Hmvc4Xna0y/ZRfv0kJbi1z9yAE8IN6eKESOw== X-Received: by 2002:a62:178f:: with SMTP id 137-v6mr37725488pfx.215.1540045604080; Sat, 20 Oct 2018 07:26:44 -0700 (PDT) Received: from mita-MS-7A45.lan ([240f:34:212d:1:28d8:ef69:4040:67dc]) by smtp.gmail.com with ESMTPSA id q68-v6sm28624799pfb.160.2018.10.20.07.26.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Sat, 20 Oct 2018 07:26:43 -0700 (PDT) From: Akinobu Mita To: linux-media@vger.kernel.org Cc: Akinobu Mita , Matt Ranostay , Sakari Ailus , Hans Verkuil , Mauro Carvalho Chehab Subject: [PATCH v4 1/6] media: video-i2c: avoid accessing released memory area when removing driver Date: Sat, 20 Oct 2018 23:26:23 +0900 Message-Id: <1540045588-9091-2-git-send-email-akinobu.mita@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1540045588-9091-1-git-send-email-akinobu.mita@gmail.com> References: <1540045588-9091-1-git-send-email-akinobu.mita@gmail.com> Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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") Cc: Matt Ranostay Cc: Sakari Ailus Cc: Hans Verkuil Cc: Mauro Carvalho Chehab Reviewed-by: Matt Ranostay Signed-off-by: Akinobu Mita Acked-by: Sakari Ailus --- * v4 - Add Reviewed-by line 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 06d29d8..f27d294 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; }