From patchwork Sun Aug 30 15:04:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guenter Roeck X-Patchwork-Id: 258725 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=-12.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 355C2C433E6 for ; Sun, 30 Aug 2020 15:06:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0606A20720 for ; Sun, 30 Aug 2020 15:06:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UpO3YKI6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727031AbgH3PFw (ORCPT ); Sun, 30 Aug 2020 11:05:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726479AbgH3PE5 (ORCPT ); Sun, 30 Aug 2020 11:04:57 -0400 Received: from mail-oi1-x244.google.com (mail-oi1-x244.google.com [IPv6:2607:f8b0:4864:20::244]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75339C06123A; Sun, 30 Aug 2020 08:04:57 -0700 (PDT) Received: by mail-oi1-x244.google.com with SMTP id j7so4987008oij.9; Sun, 30 Aug 2020 08:04:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=ZkNcNHVU6ZdU0VSPf8SeudCLMA4dEM0Dg2KzNaFvtGE=; b=UpO3YKI6UQgD7Xdn2rcCT/uQz+L2twkbkTjDy+RojmAPSG+Gp4QIzNuK+DvVrIDVOJ eSo0BabTjvvpoWIgIGg3zxLBQ41gPRLZJXZ2MnzKWwp8S2DyMdnz5fmSb/0/d0alctqy rDJ2fMioRGlUtb7qkJInnbBD0CBQDIdkJt5sf4bU3E+94eQkP4gxDw9RCWFiyilego5D uikWnuZyngSfMiLP4XfFpx4/jJ3kNdxhjUNU9KylWY2aLlIZwFz0NS0qtS140N/Oa2ja x5+9MpHYWuSMtu0+5wAdfP3x7PWDZk1xs37OHDYgk4H4/aKHwpbeguwRaGOhMlnosBXd O1SA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references; bh=ZkNcNHVU6ZdU0VSPf8SeudCLMA4dEM0Dg2KzNaFvtGE=; b=tBYgxEGMfM33cDWIT5sEgNKLsmuLiWfpIRrzDoIeZFfwxW+W63HKTSK2OHbIgXFEP0 CIxClmnBITwi9uO1xdkY/X34DJo8A0/fGn396QYvY7wnNl2ZcKLWAg8if0lO4XTQYUH4 v3bLcpbIvfNhh4SD8ziFpmwEwTS1MaXm2f6spB7QO8o4Bv4ztntY5iOKUoudIoCtCrCl LCd7doDMRkENYYD194YGIhU4jq8FXUZxfrJ7Dr9BOfBLgC+WMbVCKA6rE4CpzBQ5BKZi nzVLPArBzVjFIfsuznpSZ3pr7nupYgeGluDV79WqNmbYSo1TkD9XR1ECwuyGDUFkXce9 Y3Bw== X-Gm-Message-State: AOAM531ESF2iH5/fAN24nFOAkV6glMz3zR6BA2/gXD8z8VROIk+PEsQD qBH7cF+TMWwf6LWYTp1hBxLvHaOuCVE= X-Google-Smtp-Source: ABdhPJwpwH5meTO8EaihTTnsgJ8Qc+B2Ncdt52ZwH/k3pp5avUFLREigtVwA9WXPHX1mCx7ZpeWqxQ== X-Received: by 2002:aca:4a13:: with SMTP id x19mr1474406oia.17.1598799894300; Sun, 30 Aug 2020 08:04:54 -0700 (PDT) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id 111sm1192674otc.15.2020.08.30.08.04.53 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Sun, 30 Aug 2020 08:04:53 -0700 (PDT) From: Guenter Roeck To: Laurent Pinchart Cc: Mauro Carvalho Chehab , Sakari Ailus , linux-uvc-devel@lists.sourceforge.net, linux-usb@vger.kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Guenter Roeck , Alan Stern , Hans Verkuil Subject: [PATCH 4/5] media: uvcvideo: Protect uvc queue file operations against disconnect Date: Sun, 30 Aug 2020 08:04:42 -0700 Message-Id: <20200830150443.167286-5-linux@roeck-us.net> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200830150443.167286-1-linux@roeck-us.net> References: <20200830150443.167286-1-linux@roeck-us.net> Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org uvc queue file operations have no mutex protection against USB disconnect. This is questionable at least for the poll operation, which has to wait for the uvc queue mutex. By the time that mutex has been acquired, is it possible that the video device has been unregistered. Protect all file operations by using the queue mutex to avoid possible race conditions. After acquiring the mutex, check if the video device is still registered, and bail out if not. Cc: Laurent Pinchart Cc: Alan Stern Cc: Hans Verkuil Signed-off-by: Guenter Roeck --- drivers/media/usb/uvc/uvc_queue.c | 32 +++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c index cd60c6c1749e..c7964177a99d 100644 --- a/drivers/media/usb/uvc/uvc_queue.c +++ b/drivers/media/usb/uvc/uvc_queue.c @@ -358,24 +358,52 @@ int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type) int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma) { - return vb2_mmap(&queue->queue, vma); + struct uvc_streaming *stream = uvc_queue_to_stream(queue); + int ret; + + mutex_lock(&queue->mutex); + if (!video_is_registered(&stream->vdev)) { + ret = -ENODEV; + goto unlock; + } + ret = vb2_mmap(&queue->queue, vma); +unlock: + mutex_unlock(&queue->mutex); + return ret; } #ifndef CONFIG_MMU unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue, unsigned long pgoff) { - return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0); + struct uvc_streaming *stream = uvc_queue_to_stream(queue); + unsigned long ret; + + mutex_lock(&queue->mutex); + if (!video_is_registered(&stream->vdev)) { + ret = -ENODEV; + goto unlock; + } + ret = vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0); +unlock: + mutex_unlock(&queue->mutex); + return ret; } #endif __poll_t uvc_queue_poll(struct uvc_video_queue *queue, struct file *file, poll_table *wait) { + struct uvc_streaming *stream = uvc_queue_to_stream(queue); __poll_t ret; mutex_lock(&queue->mutex); + if (!video_is_registered(&stream->vdev)) { + ret = -ENODEV; + goto unlock; + } ret = vb2_poll(&queue->queue, file, wait); +unlock: mutex_unlock(&queue->mutex); return ret;