USB: prevent buggy hubs from crashing the USB stack

commit d199c96d41d80a567493e12b8e96ea056a1350c1 upstream.

If anyone comes across a high-speed hub that (by mistake or by design)
claims to have no Transaction Translators, plugging a full- or
low-speed device into it will cause the USB stack to crash.  This
patch (as1446) prevents the problem by ignoring such devices, since
the kernel has no way to communicate with them.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Perry Neben <neben@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 53467b526b1257117679a79144cb4903d4347b96..0b156a55c5a64b9fb367fabae59419fdc7b3ee76 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2721,6 +2721,11 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
                udev->ttport = hdev->ttport;
        } else if (udev->speed != USB_SPEED_HIGH
                        && hdev->speed == USB_SPEED_HIGH) {
+               if (!hub->tt.hub) {
+                       dev_err(&udev->dev, "parent hub has no TT\n");
+                       retval = -EINVAL;
+                       goto fail;
+               }
                udev->tt = &hub->tt;
                udev->ttport = port1;
        }