Commit 49be8dc5 authored Dec 12, 2018 by Hui Peng Committed by Greg Kroah-Hartman Dec 29, 2018

USB: hso: Fix OOB memory access in hso_probe/hso_get_config_data



commit 5146f95df782b0ac61abde36567e718692725c89 upstream.

The function hso_probe reads if_num from the USB device (as an u8) and uses
it without a length check to index an array, resulting in an OOB memory read
in hso_probe or hso_get_config_data.

Add a length check for both locations and updated hso_probe to bail on
error.

This issue has been assigned CVE-2018-19985.

Reported-by: Hui Peng <benquike@gmail.com>
Reported-by: Mathias Payer <mathias.payer@nebelwelt.net>
Signed-off-by: Hui Peng <benquike@gmail.com>
Signed-off-by: Mathias Payer <mathias.payer@nebelwelt.net>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 3845c736

drivers/net/usb/hso.c

+16 −2

Original line number	Diff line number	Diff line
		@@ -2806,6 +2806,12 @@ static int hso_get_config_data(struct usb_interface *interface)
		return -EIO;
		}

		/* check if we have a valid interface */
		if (if_num > 16) {
		kfree(config_data);
		return -EINVAL;
		}

		switch (config_data[if_num]) {
		case 0x0:
		result = 0;
		@@ -2876,10 +2882,18 @@ static int hso_probe(struct usb_interface *interface,

		/* Get the interface/port specification from either driver_info or from
		* the device itself */
		if (id->driver_info)
		if (id->driver_info) {
		/* if_num is controlled by the device, driver_info is a 0 terminated
		* array. Make sure, the access is in bounds! */
		for (i = 0; i <= if_num; ++i)
		if (((u32 *)(id->driver_info))[i] == 0)
		goto exit;
		port_spec = ((u32 *)(id->driver_info))[if_num];
		else
		} else {
		port_spec = hso_get_config_data(interface);
		if (port_spec < 0)
		goto exit;
		}

		/* Check if we need to switch to alt interfaces prior to port
		* configuration */