patch "usb: gadget: composite: correctly initialize ep->maxpacket" added to usb-next

patch "usb: gadget: composite: correctly initialize ep->maxpacket" added to usb-next

[gregkh]

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

    usb: gadget: composite: correctly initialize ep->maxpacket

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-next branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will also be merged in the next major kernel release
during the merge window.

If you have any questions about this process, please let me know.


>From e8f29bb719b47a234f33b0af62974d7a9521a52c Mon Sep 17 00:00:00 2001
From: Felipe Balbi <felipe.balbi@linux.intel.com>
Date: Wed, 28 Sep 2016 10:38:11 +0300
Subject: usb: gadget: composite: correctly initialize ep->maxpacket

usb_endpoint_maxp() returns wMaxPacketSize in its
raw form. Without taking into consideration that it
also contains other bits reserved for isochronous
endpoints.

This patch fixes one occasion where this is a
problem by making sure that we initialize
ep->maxpacket only with lower 10 bits of the value
returned by usb_endpoint_maxp(). Note that seperate
patches will be necessary to audit all call sites of
usb_endpoint_maxp() and make sure that
usb_endpoint_maxp() only returns lower 10 bits of
wMaxPacketSize.

Cc: <stable@vger.kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
---
 drivers/usb/gadget/composite.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 32176f779861..f6a7583ab6d1 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -197,7 +197,7 @@ int config_ep_by_speed(struct usb_gadget *g,
 
 ep_found:
 	/* commit results */
-	_ep->maxpacket = usb_endpoint_maxp(chosen_desc);
+	_ep->maxpacket = usb_endpoint_maxp(chosen_desc) & 0x7ff;
 	_ep->desc = chosen_desc;
 	_ep->comp_desc = NULL;
 	_ep->maxburst = 0;
-- 
2.10.2