tree de9048eb3f09838828b52ee2bae5d0b9275a4ac1
parent 3e595e41a1d31b9dad72dc959b6e85bae59c62a9
author Peter Korsgaard <peter@korsgaard.com> 1712225195 +0200
committer Vegard Nossum <vegard.nossum@oracle.com> 1717418850 +0000

usb: gadget: composite: fix OS descriptors w_value logic

commit ec6ce7075ef879b91a8710829016005dc8170f17 upstream.

The OS descriptors logic had the high/low byte of w_value inverted, causing
the extended properties to not be accessible for interface != 0.

>From the Microsoft documentation:
https://learn.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-os-1-0-descriptors-specification

OS_Desc_CompatID.doc (w_index = 0x4):

- wValue:

  High Byte = InterfaceNumber.  InterfaceNumber is set to the number of the
  interface or function that is associated with the descriptor, typically
  0x00.  Because a device can have only one extended compat ID descriptor,
  it should ignore InterfaceNumber, regardless of the value, and simply
  return the descriptor.

  Low Byte = 0.  PageNumber is used to retrieve descriptors that are larger
  than 64 KB.  The header section is 16 bytes, so PageNumber is set to 0 for
  this request.

We currently do not support >64KB compat ID descriptors, so verify that the
low byte is 0.

OS_Desc_Ext_Prop.doc (w_index = 0x5):

- wValue:

  High byte = InterfaceNumber.  The high byte of wValue is set to the number
  of the interface or function that is associated with the descriptor.

  Low byte = PageNumber.  The low byte of wValue is used to retrieve
  descriptors that are larger than 64 KB.  The header section is 10 bytes, so
  PageNumber is set to 0 for this request.

We also don't support >64KB extended properties, so verify that the low byte
is 0 and use the high byte for the interface number.

Fixes: 37a3a533429e ("usb: gadget: OS Feature Descriptors support")
Cc: stable <stable@kernel.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Link: https://lore.kernel.org/r/20240404100635.3215340-1-peter@korsgaard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit c037e0ebc0cabb1906203ca3322ad9dc7eeddc8e)
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>