From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 266241494D9; Fri, 6 Dec 2024 14:40:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733496057; cv=none; b=mYRrs9AH69GSjOo/gYtHPgNO2Po9M1+CBBdw+7Cn/0PqBnkRVVzpBkzn9xOetfAo7gLhFJyz/S3eH0KJrsx7ZfkDzv6H8AowMmz44GUQLe1YRDinLpZppwq+9X+6ZnhLUBURpLwAMijFXqKpbVsZs5pwr3fmVKJtwvflphSjcv4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733496057; c=relaxed/simple; bh=mBqEtG3V4qbhNNlJCAzw4G1//jktCLh45TWFBth+d90=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=k/uR+ZCOJHiyKoUX01rFurl6cGyQSU/ovQbdr1ycDZgecTdQC7h0Q0ydBUcMm2XFPtApiZQUZm+k0QVsKQagI6OuAVEZNtGdT040w9Yfk7kiUeJIihDVpY2phe6G0gZ52Nvrz2rMs09drVcBJdKwyZDHBWqQEUEnbTNAAr0xmgc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=V/pJeepy; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="V/pJeepy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8DCEFC4CEDC; Fri, 6 Dec 2024 14:40:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1733496057; bh=mBqEtG3V4qbhNNlJCAzw4G1//jktCLh45TWFBth+d90=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V/pJeepyC4LpxtHXfUabzF8TaW7K8YBlKRURsy9Q2rIdre+K8urDLonI3slK9IepE 2iuE/tfDTWOmBM2SBNT19KypSPf+W1TSienURUCK+KyKBAqtAZZMaUaiVz7sw2UeWE XE/e+hto+Lg+Cx+7UGY7riLQ+ugbD2wNRImAgPX4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hans Verkuil , Ricardo Ribalda , Mauro Carvalho Chehab Subject: [PATCH 6.12 038/146] media: uvcvideo: Stop stream during unregister Date: Fri, 6 Dec 2024 15:36:09 +0100 Message-ID: <20241206143529.131554559@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241206143527.654980698@linuxfoundation.org> References: <20241206143527.654980698@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ricardo Ribalda commit c9ec6f1736363b2b2bb4e266997389740f628441 upstream. uvc_unregister_video() can be called asynchronously from uvc_disconnect(). If the device is still streaming when that happens, a plethora of race conditions can occur. Make sure that the device has stopped streaming before exiting this function. If the user still holds handles to the driver's file descriptors, any ioctl will return -ENODEV from the v4l2 core. This change makes uvc more consistent with the rest of the v4l2 drivers using the vb2_fop_* and vb2_ioctl_* helpers. This driver (and many other usb drivers) always had this problem, but it wasn't possible to easily fix this until the vb2_video_unregister_device() helper was added. So the Fixes tag points to the creation of that helper. Reviewed-by: Hans Verkuil Suggested-by: Hans Verkuil Signed-off-by: Ricardo Ribalda Reviewed-by: Mauro Carvalho Chehab Fixes: f729ef5796d8 ("media: videobuf2-v4l2.c: add vb2_video_unregister_device helper function") Cc: stable@vger.kernel.org # 5.10.x [hverkuil: add note regarding Fixes version] Signed-off-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/uvc/uvc_driver.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) --- a/drivers/media/usb/uvc/uvc_driver.c +++ b/drivers/media/usb/uvc/uvc_driver.c @@ -1919,11 +1919,41 @@ static void uvc_unregister_video(struct struct uvc_streaming *stream; list_for_each_entry(stream, &dev->streams, list) { + /* Nothing to do here, continue. */ if (!video_is_registered(&stream->vdev)) continue; + /* + * For stream->vdev we follow the same logic as: + * vb2_video_unregister_device(). + */ + + /* 1. Take a reference to vdev */ + get_device(&stream->vdev.dev); + + /* 2. Ensure that no new ioctls can be called. */ video_unregister_device(&stream->vdev); - video_unregister_device(&stream->meta.vdev); + + /* 3. Wait for old ioctls to finish. */ + mutex_lock(&stream->mutex); + + /* 4. Stop streaming. */ + uvc_queue_release(&stream->queue); + + mutex_unlock(&stream->mutex); + + put_device(&stream->vdev.dev); + + /* + * For stream->meta.vdev we can directly call: + * vb2_video_unregister_device(). + */ + vb2_video_unregister_device(&stream->meta.vdev); + + /* + * Now both vdevs are not streaming and all the ioctls will + * return -ENODEV. + */ uvc_debugfs_cleanup_stream(stream); }