[ 3.5.y.z extended stable ] Patch "usbfs: Always allow ctrl requests with USB_RECIP_ENDPOINT on" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    usbfs: Always allow ctrl requests with USB_RECIP_ENDPOINT on

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From daad54d3dd678e828f468f909a0dc608d40262b4 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede at redhat.com>
Date: Tue, 16 Apr 2013 11:08:33 +0200
Subject: [PATCH] usbfs: Always allow ctrl requests with USB_RECIP_ENDPOINT on
 the ctrl ep

commit 1361bf4b9f9ef45e628a5b89e0fd9bedfdcb7104 upstream.

When usbfs receives a ctrl-request from userspace it calls check_ctrlrecip,
which for a request with USB_RECIP_ENDPOINT tries to map this to an interface
to see if this interface is claimed, except for ctrl-requests with a type of
USB_TYPE_VENDOR.

When trying to use this device: http://www.akaipro.com/eiepro
redirected to a Windows vm running on qemu on top of Linux.

The windows driver makes a ctrl-req with USB_TYPE_CLASS and
USB_RECIP_ENDPOINT with index 0, and the mapping of the endpoint (0) to
the interface fails since ep 0 is the ctrl endpoint and thus never is
part of an interface.

This patch fixes this ctrl-req failing by skipping the checkintf call for
USB_RECIP_ENDPOINT ctrl-reqs on the ctrl endpoint.

Reported-by: Dave Stikkolorum <d.r.stikkolorum at hhs.nl>
Tested-by: Dave Stikkolorum <d.r.stikkolorum at hhs.nl>
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
Acked-by: Alan Stern <stern at rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/usb/core/devio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 62679bc..f70b887 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -681,6 +681,8 @@ static int check_ctrlrecip(struct dev_state *ps, unsigned int requesttype,
 	index &= 0xff;
 	switch (requesttype & USB_RECIP_MASK) {
 	case USB_RECIP_ENDPOINT:
+		if ((index & ~USB_DIR_IN) == 0)
+			return 0;
 		ret = findintfep(ps->dev, index);
 		if (ret >= 0)
 			ret = checkintf(ps, ret);
--
1.8.1.2