4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> commit 1245374e9b8340fc255fd51b2015173a83050d03 upstream. At xhci removal the USB3 hcd (shared_hcd) is removed before the primary USB2 hcd. Interrupts for port status changes may still occur for USB3 ports after the shared_hcd is freed, causing NULL pointer dereference. Check if xhci->shared_hcd is still valid before handing USB3 port events Cc: <stable@xxxxxxxxxxxxxxx> Reported-by: Peter Chen <peter.chen@xxxxxxx> Tested-by: Jack Pham <jackp@xxxxxxxxxxxxxx> Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/host/xhci-ring.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1552,6 +1552,13 @@ static void handle_port_status(struct xh goto cleanup; } + /* We might get interrupts after shared_hcd is removed */ + if (port->rhub == &xhci->usb3_rhub && xhci->shared_hcd == NULL) { + xhci_dbg(xhci, "ignore port event for removed USB3 hcd\n"); + bogus_port_status = true; + goto cleanup; + } + hcd = port->rhub->hcd; bus_state = &xhci->bus_state[hcd_index(hcd)]; hcd_portnum = port->hcd_portnum;