Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934760AbbDIJmI (ORCPT ); Thu, 9 Apr 2015 05:42:08 -0400 Received: from mail.kernel.org ([198.145.29.136]:42429 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755317AbbDIIyk (ORCPT ); Thu, 9 Apr 2015 04:54:40 -0400 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Johan Hovold , Zefan Li Subject: [PATCH 3.4 097/176] USB: console: fix potential use after free Date: Thu, 9 Apr 2015 16:45:45 +0800 Message-Id: <1428569224-23820-97-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1428569028-23762-1-git-send-email-lizf@kernel.org> References: <1428569028-23762-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2555 Lines: 84 From: Johan Hovold 3.4.107-rc1 review patch. If anyone has any objections, please let me know. ------------------ commit 32a4bf2e81ec378e5925d4e069e0677a6c86a6ad upstream. Use tty kref to release the fake tty in usb_console_setup to avoid use after free if the underlying serial driver has acquired a reference. Note that using the tty destructor release_one_tty requires some more state to be initialised. Fixes: 4a90f09b20f4 ("tty: usb-serial krefs") Signed-off-by: Johan Hovold [lizf: Backported to 3.4: adjust context] Signed-off-by: Zefan Li --- drivers/usb/serial/console.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/usb/serial/console.c b/drivers/usb/serial/console.c index 1ee6b2a..ae0fa72 100644 --- a/drivers/usb/serial/console.c +++ b/drivers/usb/serial/console.c @@ -47,6 +47,8 @@ static struct console usbcons; * ------------------------------------------------------------ */ +static const struct tty_operations usb_console_fake_tty_ops = { +}; /* * The parsing of the command line works exactly like the @@ -141,14 +143,17 @@ static int usb_console_setup(struct console *co, char *options) goto reset_open_count; } kref_init(&tty->kref); - tty_port_tty_set(&port->port, tty); tty->driver = usb_serial_tty_driver; tty->index = co->index; + INIT_LIST_HEAD(&tty->tty_files); + kref_get(&tty->driver->kref); + tty->ops = &usb_console_fake_tty_ops if (tty_init_termios(tty)) { retval = -ENOMEM; err("no more memory"); - goto free_tty; + goto put_tty; } + tty_port_tty_set(&port->port, tty); } /* only call the device specific open if this @@ -170,7 +175,7 @@ static int usb_console_setup(struct console *co, char *options) serial->type->set_termios(tty, port, &dummy); tty_port_tty_set(&port->port, NULL); - kfree(tty); + tty_kref_put(tty); } set_bit(ASYNCB_INITIALIZED, &port->port.flags); } @@ -186,8 +191,8 @@ static int usb_console_setup(struct console *co, char *options) fail: tty_port_tty_set(&port->port, NULL); - free_tty: - kfree(tty); + put_tty: + tty_kref_put(tty); reset_open_count: port->port.count = 0; usb_autopm_put_interface(serial->interface); -- 1.9.1 -- 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/