| From: Hui Peng <benquike@gmail.com> |
| Date: Wed, 12 Dec 2018 12:42:24 +0100 |
| Subject: 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: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| drivers/net/usb/hso.c | 18 ++++++++++++++++-- |
| 1 file changed, 16 insertions(+), 2 deletions(-) |
| |
| --- a/drivers/net/usb/hso.c |
| +++ b/drivers/net/usb/hso.c |
| @@ -2812,6 +2812,12 @@ static int hso_get_config_data(struct us |
| 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; |
| @@ -2882,10 +2888,18 @@ static int hso_probe(struct usb_interfac |
| |
| /* 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 */ |
