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 --- drivers/usb/host/xhci-ring.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 9e90d2952760..1db61bb2b9b5 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2524,9 +2524,8 @@ 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) ||