From patchwork Tue Apr 30 10:41:37 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zheng Yejian X-Patchwork-Id: 13648734 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (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 2934612C47A; Tue, 30 Apr 2024 10:40:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.187 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714473643; cv=none; b=l0N19JQxicVyWT7jalwOWggXnjuaEL770YgUMezFOqlZzbpGPv1YUre3LaFRwJ1yK958ySLOJ4Xf9FHH9o23o6fyadImYCaVQYjJy+MOU793WhVQrIEIDnMPAqlQCNDZ+q64L91Fnyx8aDF7/5euatNfyn261tYWKq7vTiwZaBc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714473643; c=relaxed/simple; bh=spuDbDMDBL3D0ud6jPnHsaLTenJfMN5QsjwFYIiViXA=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=XqQ7AFEn4dWxD7q4qniN/WzBFXzTBjSZOmwsUyL6KVhSG9ehqBCJLBpboRqQm1/h3X5kMCUkU+dVYUlHrvJTADUfC+gtHZLG2lUV9dw3+uX3cbP4tuF/76VJO6OlJSXXEpHtxQ6MCBkawJNL/0YDpK+I8pk6OOFJCEWQ5msTf8o= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.194]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4VTGq360bXzxNfM; Tue, 30 Apr 2024 18:37:19 +0800 (CST) Received: from dggpeml500012.china.huawei.com (unknown [7.185.36.15]) by mail.maildlp.com (Postfix) with ESMTPS id 31A8A14035F; Tue, 30 Apr 2024 18:40:37 +0800 (CST) Received: from localhost.localdomain (10.67.175.61) by dggpeml500012.china.huawei.com (7.185.36.15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Tue, 30 Apr 2024 18:40:36 +0800 From: Zheng Yejian To: , CC: , , Subject: [PATCH v2] media: dvb-usb: Fix unexpected infinite loop in dvb_usb_read_remote_control() Date: Tue, 30 Apr 2024 18:41:37 +0800 Message-ID: <20240430104137.1014471-1-zhengyejian1@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240412135256.1546051-1-zhengyejian1@huawei.com> References: <20240412135256.1546051-1-zhengyejian1@huawei.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpeml500012.china.huawei.com (7.185.36.15) Infinite log printing occurs during fuzz test: rc rc1: DViCO FusionHDTV DVB-T USB (LGZ201) as ... ... dvb-usb: schedule remote query interval to 100 msecs. dvb-usb: DViCO FusionHDTV DVB-T USB (LGZ201) successfully initialized ... dvb-usb: bulk message failed: -22 (1/0) dvb-usb: bulk message failed: -22 (1/0) dvb-usb: bulk message failed: -22 (1/0) ... dvb-usb: bulk message failed: -22 (1/0) Looking into the codes, there is a loop in dvb_usb_read_remote_control(), that is in rc_core_dvb_usb_remote_init() create a work that will call dvb_usb_read_remote_control(), and this work will reschedule itself at 'rc_interval' intervals to recursively call dvb_usb_read_remote_control(), see following code snippet: rc_core_dvb_usb_remote_init() { ... INIT_DELAYED_WORK(&d->rc_query_work, dvb_usb_read_remote_control); schedule_delayed_work(&d->rc_query_work, msecs_to_jiffies(rc_interval)); ... } dvb_usb_read_remote_control() { ... err = d->props.rc.core.rc_query(d); if (err) err(...) // Did not return even if query failed schedule_delayed_work(&d->rc_query_work, msecs_to_jiffies(rc_interval)); } When the infinite log printing occurs, the query callback 'd->props.rc.core.rc_query' is cxusb_rc_query(). And the log is due to the failure of finding a valid 'generic_bulk_ctrl_endpoint' in usb_bulk_msg(), see following code snippet: cxusb_rc_query() { cxusb_ctrl_msg() { dvb_usb_generic_rw() { ret = usb_bulk_msg(d->udev, usb_sndbulkpipe(d->udev, d->props.generic_bulk_ctrl_endpoint),...); if (ret) err("bulk message failed: %d (%d/%d)",ret,wlen,actlen); ... } ... } By analyzing the corresponding USB descriptor, it shows that the bNumEndpoints is 0 in its interface descriptor, but the 'generic_bulk_ctrl_endpoint' is 1, that means user don't configure a valid endpoint for 'generic_bulk_ctrl_endpoint', therefore this 'invalid' USB device should be rejected before it calls into dvb_usb_read_remote_control(). To fix it, we need to add endpoint check for 'generic_bulk_ctrl_endpoint'. And as Sean suggested, the same check and clear halts should be done for 'generic_bulk_ctrl_endpoint_response'. So introduce dvb_usb_check_bulk_endpoint() to do it for both of them. Fixes: 4d43e13f723e ("V4L/DVB (4643): Multi-input patch for DVB-USB device") Signed-off-by: Zheng Yejian --- drivers/media/usb/dvb-usb/dvb-usb-init.c | 27 ++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-) v2: - As Sean suggested, check endpoint and clear halt for both 'generic_bulk_ctrl_endpoint' and 'generic_bulk_ctrl_endpoint_response' with the new introduced dvb_usb_check_bulk_endpoint(); Link: https://lore.kernel.org/all/ZjCl97Ww6NrzJQCB@gofer.mess.org/ Link: https://lore.kernel.org/all/ZjC7rXU7ViaH60_S@gofer.mess.org/ - Add Fixes tag. v1: - Link: https://lore.kernel.org/all/20240412135256.1546051-1-zhengyejian1@huawei.com/ diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c index fbf58012becd..7eb321bab84f 100644 --- a/drivers/media/usb/dvb-usb/dvb-usb-init.c +++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c @@ -23,6 +23,23 @@ static int dvb_usb_force_pid_filter_usage; module_param_named(force_pid_filter_usage, dvb_usb_force_pid_filter_usage, int, 0444); MODULE_PARM_DESC(force_pid_filter_usage, "force all dvb-usb-devices to use a PID filter, if any (default: 0)."); +static int dvb_usb_check_bulk_endpoint(struct dvb_usb_device *d, u8 endpoint) +{ + if (endpoint) { + int ret; + + ret = usb_pipe_type_check(d->udev, usb_sndbulkpipe(d->udev, endpoint)); + if (ret) + return ret; + ret = usb_pipe_type_check(d->udev, usb_rcvbulkpipe(d->udev, endpoint)); + if (ret) + return ret; + usb_clear_halt(d->udev, usb_sndbulkpipe(d->udev, endpoint)); + usb_clear_halt(d->udev, usb_rcvbulkpipe(d->udev, endpoint)); + } + return 0; +} + static int dvb_usb_adapter_init(struct dvb_usb_device *d, short *adapter_nrs) { struct dvb_usb_adapter *adap; @@ -103,10 +120,12 @@ static int dvb_usb_adapter_init(struct dvb_usb_device *d, short *adapter_nrs) * when reloading the driver w/o replugging the device * sometimes a timeout occurs, this helps */ - if (d->props.generic_bulk_ctrl_endpoint != 0) { - usb_clear_halt(d->udev, usb_sndbulkpipe(d->udev, d->props.generic_bulk_ctrl_endpoint)); - usb_clear_halt(d->udev, usb_rcvbulkpipe(d->udev, d->props.generic_bulk_ctrl_endpoint)); - } + ret = dvb_usb_check_bulk_endpoint(d, d->props.generic_bulk_ctrl_endpoint); + if (ret) + goto frontend_init_err; + ret = dvb_usb_check_bulk_endpoint(d, d->props.generic_bulk_ctrl_endpoint_response); + if (ret) + goto frontend_init_err; return 0;