4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Johan Hovold <johan@xxxxxxxxxx>
commit 2c25a2c818023df64463aac3288a9f969491e507 upstream.
A SuperSpeed hub descriptor does not have any variable-length fields so
bail out when reading a short descriptor.
This avoids parsing and leaking two bytes of uninitialised slab data
through sysfs removable-attributes.
Fixes: dbe79bbe9dcb ("USB 3.0 Hub Changes")
Cc: John Youn <John.Youn@xxxxxxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/core/hub.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -376,8 +376,12 @@ static int get_hub_descriptor(struct usb
USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
dtype << 8, 0, data, size,
USB_CTRL_GET_TIMEOUT);
- if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2))
+ if (hub_is_superspeed(hdev)) {
+ if (ret == size)
+ return ret;
+ } else if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2)) {
return ret;
+ }
}
return -EINVAL;
}
@@ -1303,7 +1307,7 @@ static int hub_configure(struct usb_hub
/* Request the entire hub descriptor.
* hub->descriptor can handle USB_MAXCHILDREN ports,
- * but the hub can/will return fewer bytes here.
+ * but a (non-SS) hub can/will return fewer bytes here.
*/
ret = get_hub_descriptor(hdev, hub->descriptor);
if (ret < 0) {