Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753254Ab1B1JeN (ORCPT ); Mon, 28 Feb 2011 04:34:13 -0500 Received: from mail.pripojeni.net ([217.66.174.14]:36585 "EHLO smtp.pripojeni.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752384Ab1B1JeL (ORCPT ); Mon, 28 Feb 2011 04:34:11 -0500 From: Jiri Slaby To: gregkh@suse.de Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, jirislaby@gmail.com, Alan Cox Subject: [PATCH 1/2] USB: serial/keyspan_pda, fix potential tty NULL dereferences Date: Mon, 28 Feb 2011 10:34:05 +0100 Message-Id: <1298885646-9293-1-git-send-email-jslaby@suse.cz> X-Mailer: git-send-email 1.7.4.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2622 Lines: 81 Make sure that we check the return value of tty_port_tty_get. Sometimes it may return NULL and we later dereference that. There are several places to check. For easier handling, tty_port_tty_get is moved directly to the palce where needed in keyspan_pda_rx_interrupt. Signed-off-by: Jiri Slaby Cc: Alan Cox Cc: Greg Kroah-Hartman --- drivers/usb/serial/keyspan_pda.c | 15 ++++++++------- 1 files changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c index 554a869..7b690f3 100644 --- a/drivers/usb/serial/keyspan_pda.c +++ b/drivers/usb/serial/keyspan_pda.c @@ -173,7 +173,8 @@ static void keyspan_pda_wakeup_write(struct work_struct *work) container_of(work, struct keyspan_pda_private, wakeup_work); struct usb_serial_port *port = priv->port; struct tty_struct *tty = tty_port_tty_get(&port->port); - tty_wakeup(tty); + if (tty) + tty_wakeup(tty); tty_kref_put(tty); } @@ -206,7 +207,7 @@ static void keyspan_pda_request_unthrottle(struct work_struct *work) static void keyspan_pda_rx_interrupt(struct urb *urb) { struct usb_serial_port *port = urb->context; - struct tty_struct *tty = tty_port_tty_get(&port->port); + struct tty_struct *tty; unsigned char *data = urb->transfer_buffer; int retval; int status = urb->status; @@ -223,7 +224,7 @@ static void keyspan_pda_rx_interrupt(struct urb *urb) /* this urb is terminated, clean up */ dbg("%s - urb shutting down with status: %d", __func__, status); - goto out; + return; default: dbg("%s - nonzero urb status received: %d", __func__, status); @@ -233,12 +234,14 @@ static void keyspan_pda_rx_interrupt(struct urb *urb) /* see if the message is data or a status interrupt */ switch (data[0]) { case 0: - /* rest of message is rx data */ - if (urb->actual_length) { + tty = tty_port_tty_get(&port->port); + /* rest of message is rx data */ + if (tty && urb->actual_length) { tty_insert_flip_string(tty, data + 1, urb->actual_length - 1); tty_flip_buffer_push(tty); } + tty_kref_put(tty); break; case 1: /* status interrupt */ @@ -265,8 +268,6 @@ exit: dev_err(&port->dev, "%s - usb_submit_urb failed with result %d", __func__, retval); -out: - tty_kref_put(tty); } -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/