On 12/12/19 7:30 PM, Suwan Kim wrote:
If a transaction error happens in vhci_recv_ret_submit(), event
handler closes connection and changes port status to kick hub_event.
Then hub tries to flush the endpoint URBs, but that causes infinite
loop between usb_hub_flush_endpoint() and vhci_urb_dequeue() because
"vhci_priv" in vhci_urb_dequeue() was already released by
vhci_recv_ret_submit() before a transmission error occurred. Thus,
vhci_urb_dequeue() terminates early and usb_hub_flush_endpoint()
continuously calls vhci_urb_dequeue().
The root cause of this issue is that vhci_recv_ret_submit()
terminates early without giving back URB when transaction error
occurs in vhci_recv_ret_submit(). That causes the error URB to still
be linked at endpoint list without “vhci_priv".
So, in the case of transaction error in vhci_recv_ret_submit(),
unlink URB from the endpoint, insert proper error code in
urb->status and give back URB.
Reported-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
Tested-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Suwan Kim <suwan.kim027@xxxxxxxxx>
---
drivers/usb/usbip/vhci_rx.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/usbip/vhci_rx.c b/drivers/usb/usbip/vhci_rx.c
index 33f8972ba842..00fc98741c5d 100644
--- a/drivers/usb/usbip/vhci_rx.c
+++ b/drivers/usb/usbip/vhci_rx.c
@@ -77,16 +77,21 @@ static void vhci_recv_ret_submit(struct vhci_device *vdev,
usbip_pack_pdu(pdu, urb, USBIP_RET_SUBMIT, 0);
/* recv transfer buffer */
- if (usbip_recv_xbuff(ud, urb) < 0)
- return;
+ if (usbip_recv_xbuff(ud, urb) < 0) {
+ urb->status = -EPROTO;
+ goto error;
+ }
/* recv iso_packet_descriptor */
- if (usbip_recv_iso(ud, urb) < 0)
- return;
+ if (usbip_recv_iso(ud, urb) < 0) {
+ urb->status = -EPROTO;
+ goto error;
+ }
/* restore the padding in iso packets */
usbip_pad_iso(ud, urb);
+error:
if (usbip_dbg_flag_vhci_rx)
usbip_dump_urb(urb);
Acked-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
thanks,
-- Shuah
