From 4f9785cc99feeb3673993b471f646b4dbaec2cc1 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 3 Jan 2017 16:39:44 +0100 Subject: [PATCH] USB: serial: io_ti: fix another NULL-deref at open 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") Cc: stable Signed-off-by: Johan Hovold --- drivers/usb/serial/io_ti.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c index bf8a4f432f4b..3b1cfba0ec84 100644 --- a/drivers/usb/serial/io_ti.c +++ b/drivers/usb/serial/io_ti.c @@ -1508,7 +1508,7 @@ stayinbootmode: dev_dbg(dev, "%s - STAYING IN BOOT MODE\n", __func__); serial->product_info.TiMode = TI_MODE_BOOT; - return 0; + return 1; } static int ti_do_config(struct edgeport_port *port, int feature, int on) @@ -2560,14 +2560,18 @@ static int edge_startup(struct usb_serial *serial) mutex_init(&edge_serial->es_lock); edge_serial->serial = serial; + INIT_DELAYED_WORK(&edge_serial->heartbeat_work, edge_heartbeat_work); 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 */ + product_id = le16_to_cpu( edge_serial->serial->dev->descriptor.idProduct); @@ -2579,7 +2583,6 @@ static int edge_startup(struct usb_serial *serial) } } - INIT_DELAYED_WORK(&edge_serial->heartbeat_work, edge_heartbeat_work); edge_heartbeat_schedule(edge_serial); return 0;