From: Hui Peng benquike@gmail.com
[ Upstream commit 5146f95df782b0ac61abde36567e718692725c89 ]
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: Sasha Levin sashal@kernel.org --- drivers/net/usb/hso.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c index d7a3379ea668..18a0952f68a8 100644 --- a/drivers/net/usb/hso.c +++ b/drivers/net/usb/hso.c @@ -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 */