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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5397CC433F5 for ; Mon, 18 Oct 2021 09:21:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 322A460FC3 for ; Mon, 18 Oct 2021 09:21:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231230AbhJRJXr (ORCPT ); Mon, 18 Oct 2021 05:23:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:45976 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231149AbhJRJXq (ORCPT ); Mon, 18 Oct 2021 05:23:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 40060610A6; Mon, 18 Oct 2021 09:21:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1634548895; bh=45uHLhSwbxZGqieE58NQBSMQKb+4dloBQaOE2gvnbEI=; h=Subject:To:Cc:From:Date:From; b=R2ij7LD6CrwOI6D/ZMzffkKkb0XKmvopY2LQmRSfMnxHi+eXNOf21C2Zx8TMZrrZR CnoRtTYwLVN5t3RMzGQfsGGlit5KE1jxmfX1ZzPFdSorwhw+nQsfjVUMZLLBBJePve Wd2GvqhFDME7QDCViIIFaHBqGhQGSk/Bzl3Cf204= Subject: FAILED: patch "[PATCH] USB: xhci: dbc: fix tty registration race" failed to apply to 4.19-stable tree To: johan@kernel.org, baolu.lu@linux.intel.com, gregkh@linuxfoundation.org, mathias.nyman@linux.intel.com Cc: From: Date: Mon, 18 Oct 2021 11:21:25 +0200 Message-ID: <163454888522184@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 880de403777376e50bdf60def359fa50a722006f Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Fri, 8 Oct 2021 12:25:45 +0300 Subject: [PATCH] USB: xhci: dbc: fix tty registration race Make sure to allocate resources before registering the tty device to avoid having a racing open() and write() fail to enable rx or dereference a NULL pointer when accessing the uninitialised fifo. Fixes: dfba2174dc42 ("usb: xhci: Add DbC support in xHCI driver") Cc: stable@vger.kernel.org # 4.16 Cc: Lu Baolu Signed-off-by: Johan Hovold Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20211008092547.3996295-4-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/usb/host/xhci-dbgtty.c b/drivers/usb/host/xhci-dbgtty.c index 6e784f2fc26d..eb46e642e87a 100644 --- a/drivers/usb/host/xhci-dbgtty.c +++ b/drivers/usb/host/xhci-dbgtty.c @@ -408,40 +408,38 @@ static int xhci_dbc_tty_register_device(struct xhci_dbc *dbc) return -EBUSY; xhci_dbc_tty_init_port(dbc, port); - tty_dev = tty_port_register_device(&port->port, - dbc_tty_driver, 0, NULL); - if (IS_ERR(tty_dev)) { - ret = PTR_ERR(tty_dev); - goto register_fail; - } ret = kfifo_alloc(&port->write_fifo, DBC_WRITE_BUF_SIZE, GFP_KERNEL); if (ret) - goto buf_alloc_fail; + goto err_exit_port; ret = xhci_dbc_alloc_requests(dbc, BULK_IN, &port->read_pool, dbc_read_complete); if (ret) - goto request_fail; + goto err_free_fifo; ret = xhci_dbc_alloc_requests(dbc, BULK_OUT, &port->write_pool, dbc_write_complete); if (ret) - goto request_fail; + goto err_free_requests; + + tty_dev = tty_port_register_device(&port->port, + dbc_tty_driver, 0, NULL); + if (IS_ERR(tty_dev)) { + ret = PTR_ERR(tty_dev); + goto err_free_requests; + } port->registered = true; return 0; -request_fail: +err_free_requests: xhci_dbc_free_requests(&port->read_pool); xhci_dbc_free_requests(&port->write_pool); +err_free_fifo: kfifo_free(&port->write_fifo); - -buf_alloc_fail: - tty_unregister_device(dbc_tty_driver, 0); - -register_fail: +err_exit_port: xhci_dbc_tty_exit_port(port); dev_err(dbc->dev, "can't register tty port, err %d\n", ret);