Patch "USB: hub: fix SS max number of ports" has been added to the 4.9-stable tree

Patch "USB: hub: fix SS max number of ports" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    USB: hub: fix SS max number of ports

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usb-hub-fix-ss-max-number-of-ports.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 93491ced3c87c94b12220dbac0527e1356702179 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Wed, 10 May 2017 18:18:29 +0200
Subject: USB: hub: fix SS max number of ports

From: Johan Hovold <johan@kernel.org>

commit 93491ced3c87c94b12220dbac0527e1356702179 upstream.

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>

---
 drivers/usb/core/hub.c        |    8 +++++++-
 include/uapi/linux/usb/ch11.h |    3 +++
 2 files changed, 10 insertions(+), 1 deletion(-)

--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1334,7 +1334,13 @@ static int hub_configure(struct usb_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;
--- 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
  */


Patches currently in stable-queue which might be from johan@kernel.org are

queue-4.9/usb-usbip-fix-nonconforming-hub-descriptor.patch
queue-4.9/usb-gadget-dummy_hcd-fix-hub-descriptor-removable-fields.patch
queue-4.9/usb-hub-fix-ss-max-number-of-ports.patch