[PATCH 4.4 81/86] usb: xhci: fix uninitialized completion when USB3 port got wrong status

Greg Kroah-Hartman
2018-11-29T14:20:37Z

From: Aaron Ma <aaron.ma@canonical.com>

commit 958c0bd86075d4ef1c936998deefe1947e539240 upstream.

Realtek USB3.0 Card Reader [0bda:0328] reports wrong port status on
Cannon lake PCH USB3.1 xHCI [8086:a36d] after resume from S3,
after clear port reset it works fine.

Since this device is registered on USB3 roothub at boot,
when port status reports not superspeed, xhci_get_port_status will call
an uninitialized completion in bus_state[0].
Kernel will hang because of NULL pointer.

Restrict the USB2 resume status check in USB2 roothub to fix hang issue.

Cc: stable@vger.kernel.org
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/host/xhci-hub.c | 2 +-
drivers/usb/host/xhci-ring.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -744,7 +744,7 @@ static u32 xhci_get_port_status(struct u
status |= USB_PORT_STAT_SUSPEND;
}
if ((raw_port_status & PORT_PLS_MASK) == XDEV_RESUME &&
- !DEV_SUPERSPEED_ANY(raw_port_status)) {
+ !DEV_SUPERSPEED_ANY(raw_port_status) && hcd->speed < HCD_USB3) {
if ((raw_port_status & PORT_RESET) ||
!(raw_port_status & PORT_PE))
return 0xffffffff;
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1673,7 +1673,7 @@ static void handle_port_status(struct xh
* RExit to a disconnect state). If so, let the the driver know it's
* out of the RExit state.
*/
- if (!DEV_SUPERSPEED_ANY(temp) &&
+ if (!DEV_SUPERSPEED_ANY(temp) && hcd->speed < HCD_USB3 &&
test_and_clear_bit(faked_port_index,
&bus_state->rexit_ports)) {
complete(&bus_state->rexit_done[faked_port_index]);