The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 958c0bd86075d4ef1c936998deefe1947e539240 Mon Sep 17 00:00:00 2001

From: Aaron Ma aaron.ma@canonical.com Date: Fri, 9 Nov 2018 17:21:20 +0200 Subject: [PATCH] usb: xhci: fix uninitialized completion when USB3 port got wrong status

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

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index 12eea73d9f20..60e4ac7ae4f8 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -876,7 +876,7 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd, 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; diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 730a6ecd85fc..250b758efe9f 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1646,7 +1646,7 @@ static void handle_port_status(struct xhci_hcd *xhci, * RExit to a disconnect state). If so, let the the driver know it's * out of the RExit state. */ - if (!DEV_SUPERSPEED_ANY(portsc) && + if (!DEV_SUPERSPEED_ANY(portsc) && hcd->speed < HCD_USB3 && test_and_clear_bit(hcd_portnum, &bus_state->rexit_ports)) { complete(&bus_state->rexit_done[hcd_portnum]);