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xhci: Set correct transferred length for cancelled bulk transfers
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commit f026058 upstream.

The transferred length is set incorrectly for cancelled bulk
transfer TDs in case the bulk transfer ring stops on the last transfer
block with a 'Stop - Length Invalid' completion code.

length essentially ends up being set to the requested length:
urb->actual_length = urb->transfer_buffer_length

Length for 'Stop - Length Invalid' cases should be the sum of all
TRB transfer block lengths up to the one the ring stopped on,
_excluding_ the one stopped on.

Fix this by always summing up TRB lengths for 'Stop - Length Invalid'
bulk cases.

This issue was discovered by Alan Stern while debugging
https://bugzilla.kernel.org/show_bug.cgi?id=218890, but does not
solve that bug. Issue is older than 4.10 kernel but fix won't apply
to those due to major reworks in that area.

Tested-by: Pierre Tomon <pierretom+12@ik.me>
Cc: stable@vger.kernel.org # v4.10+
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20240611120610.3264502-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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matnyman authored and gregkh committed Jul 5, 2024
1 parent fc745f6 commit 22de7c9
Showing 1 changed file with 2 additions and 3 deletions.
5 changes: 2 additions & 3 deletions drivers/usb/host/xhci-ring.c
Original file line number Diff line number Diff line change
Expand Up @@ -2386,9 +2386,8 @@ static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_virt_ep *ep,
goto finish_td;
case COMP_STOPPED_LENGTH_INVALID:
/* stopped on ep trb with invalid length, exclude it */
ep_trb_len = 0;
remaining = 0;
break;
td->urb->actual_length = sum_trb_lengths(xhci, ep_ring, ep_trb);
goto finish_td;
case COMP_USB_TRANSACTION_ERROR:
if (xhci->quirks & XHCI_NO_SOFT_RETRY ||
(ep->err_count++ > MAX_SOFT_RETRY) ||
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