USB: validate wMaxPacketValue entries in endpoint descriptors

USB: validate wMaxPacketValue entries in endpoint descriptors

commit aed9d65ac3278d4febd8665bd7db59ef53e825fe upstream.

Erroneous or malicious endpoint descriptors may have non-zero bits in
reserved positions, or out-of-bounds values.  This patch helps prevent
these from causing problems by bounds-checking the wMaxPacketValue
entries in endpoint descriptors and capping the values at the maximum
allowed.

This issue was first discovered and tests were conducted by Jake Lamberson
<jake.lamberson1@gmail.com>, an intern working for Rosie Hall.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: roswest <roswest@cisco.com>
Tested-by: roswest <roswest@cisco.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: drop the USB_SPEED_SUPER_PLUS case]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>