3.16.64-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Hui Peng <benquike@xxxxxxxxx>
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@xxxxxxxxx>
Reported-by: Mathias Payer <mathias.payer@xxxxxxxxxxxxx>
Signed-off-by: Hui Peng <benquike@xxxxxxxxx>
Signed-off-by: Mathias Payer <mathias.payer@xxxxxxxxxxxxx>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
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 */
