From SourceForge: invalid URB length (less than 4 bytes), some devices don't respond

[Oxalin]

Reported by: daniel danzberger
Date: 2013-02-18
Link: https://sourceforge.net/p/usbip/discussion/418507/thread/af21439c/

Description: "invalid read lengths < 4 bytes on some urbs. Causes some devices to not respond on this urb."

Proposed fix (to be validated):
Index: busenum.c
-- busenum.c (revision 201)
+++ busenum.c (working copy)
@@ -832,15 +832,23 @@

CHECK_SIZE_READ

++ len = req->TransferBufferLength;
++
++ /* minimal read len is 4 bytes */
++ if (len != 0 && len < 4)
++ len = 4;
++
set_cmd_submit_usbip_header (h,
seqnum, devid,
USBIP_DIR_IN, 0,
-- USBD_SHORT_TRANSFER_OK, req->TransferBufferLength);
++ USBD_SHORT_TRANSFER_OK,
++ len
++ );
build_setup_packet(setup,
USBIP_DIR_IN,
BMREQUEST_STANDARD, BMREQUEST_TO_DEVICE, USB_REQUEST_GET_DESCRIPTOR);

-- setup->wLength = (unsigned short)req->TransferBufferLength;
++ setup->wLength = (unsigned short)len;
setup->wValue = (req->DescriptorType<<8) | req->Index;

switch(req->DescriptorType){
Index: busenum.h

[Oxalin]

What needs to be done:

• investigate what's the root cause of this bug and if it has been fixed;
• validate proposed fix.

[MailYouLater]

Shouldn't that diff be in a code block?

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