USB: hub: fix SS max number of ports

Add define for the maximum number of ports on a SuperSpeed hub as per
USB 3.1 spec Table 10-5, and use it when verifying the retrieved hub
descriptor.

This specifically avoids benign attempts to update the DeviceRemovable
mask for non-existing ports (should we get that far).

Fixes: dbe79bbe9dcb ("USB 3.0 Hub Changes")
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index f77a4eb..b8bb20d 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1336,7 +1336,13 @@ static int hub_configure(struct usb_hub *hub,
        if (ret < 0) {
                message = "can't read hub descriptor";
                goto fail;
-       } else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) {
+       }
+
+       maxchild = USB_MAXCHILDREN;
+       if (hub_is_superspeed(hdev))
+               maxchild = min_t(unsigned, maxchild, USB_SS_MAXPORTS);
+
+       if (hub->descriptor->bNbrPorts > maxchild) {
                message = "hub has too many ports!";
                ret = -ENODEV;
                goto fail;

diff --git a/include/uapi/linux/usb/ch11.h b/include/uapi/linux/usb/ch11.h
index 361297e..576c704 100644 (file)
--- a/include/uapi/linux/usb/ch11.h
+++ b/include/uapi/linux/usb/ch11.h
@@ -22,6 +22,9 @@
  */
 #define USB_MAXCHILDREN                31
 
+/* See USB 3.1 spec Table 10-5 */
+#define USB_SS_MAXPORTS                15
+
 /*
  * Hub request types
  */