xhci: handle port status events for removed USB3 hcd

PATCH New Mathias Nyman 1 participant 1 message Nov 12, 2018

Subsystems (2)

USB USB xHCI driver

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Mathias Nyman

author

2018-11-12 08:21 UTC #0 lore raw

PATCH 2/6 xhci: handle port status events for removed USB3 hcd

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 <[email protected]>

Reported-by Peter Chen <[email protected]>

Tested-by Jack Pham <[email protected]>

Signed-off-by Mathias Nyman <[email protected]>

---
 drivers/usb/host/xhci-ring.c | 7 +++++++
 1 file changed, 7 insertions(+)

drivers/usb/host/xhci-ring.c +7 -0

index a8d92c9..80d464e 100644
@@ -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;