Commit 9640bcac authored Dec 13, 2019 by Suwan Kim Committed by Greg Kroah-Hartman Jan 04, 2020

usbip: Fix error path of vhci_recv_ret_submit()



commit aabb5b833872524eaf28f52187e5987984982264 upstream.

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@invisiblethingslab.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Suwan Kim <suwan.kim027@gmail.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20191213023055.19933-3-suwan.kim027@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 3420bd51

drivers/usb/usbip/vhci_rx.c

+9 −4

Original line number	Diff line number	Diff line
		@@ -90,16 +90,21 @@ 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);