From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936675AbdCJNEh (ORCPT ); Fri, 10 Mar 2017 08:04:37 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:44246 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935159AbdCJLxU (ORCPT ); Fri, 10 Mar 2017 06:53:20 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Johan Hovold" Date: Fri, 10 Mar 2017 11:46:10 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 070/199] USB: serial: io_ti: fix another NULL-deref at open In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.87-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit 4f9785cc99feeb3673993b471f646b4dbaec2cc1 upstream. In case a device is left in "boot-mode" we must not register any port devices in order to avoid a NULL-pointer dereference on open due to missing endpoints. This could be used by a malicious device to trigger an OOPS: Unable to handle kernel NULL pointer dereference at virtual address 00000030 ... [] (edge_open [io_ti]) from [] (serial_port_activate+0x68/0x98 [usbserial]) [] (serial_port_activate [usbserial]) from [] (tty_port_open+0x9c/0xe8) [] (tty_port_open) from [] (serial_open+0x48/0x6c [usbserial]) [] (serial_open [usbserial]) from [] (tty_open+0xcc/0x5cc) Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Johan Hovold [bwh: Backported to 3.2: - No heartbeat_work to initialise earlier - No separate port_probe and port_remove operations, so add check for null port pointers in edge_release() - Adjust context] Signed-off-by: Ben Hutchings --- drivers/usb/serial/io_ti.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/drivers/usb/serial/io_ti.c +++ b/drivers/usb/serial/io_ti.c @@ -1500,7 +1500,7 @@ stayinbootmode: dbg("%s - STAYING IN BOOT MODE", __func__); serial->product_info.TiMode = TI_MODE_BOOT; - return 0; + return 1; } @@ -2660,11 +2660,14 @@ static int edge_startup(struct usb_seria usb_set_serial_data(serial, edge_serial); status = download_fw(edge_serial); - if (status) { + if (status < 0) { kfree(edge_serial); return status; } + if (status > 0) + return 1; /* bind but do not register any ports */ + /* set up our port private structures */ for (i = 0; i < serial->num_ports; ++i) { edge_port = kzalloc(sizeof(struct edgeport_port), GFP_KERNEL); @@ -2715,6 +2718,8 @@ static void edge_release(struct usb_seri for (i = 0; i < serial->num_ports; ++i) { edge_port = usb_get_serial_port_data(serial->port[i]); + if (!edge_port) + continue; kfifo_free(&edge_port->write_fifo); kfree(edge_port); }