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@vger.kernel.org Reported-by: Peter Chen peter.chen@nxp.com Tested-by: Jack Pham jackp@codeaurora.org Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com --- drivers/usb/host/xhci-ring.c | 7 +++++++ 1 file changed, 7 insertions(+)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index a8d92c9..80d464e 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1556,6 +1556,13 @@ static void handle_port_status(struct xhci_hcd *xhci, 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;