On 27.09.2018 19:26, Mathias Nyman wrote:
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>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
---
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 f0a99aa..3d314b8 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1552,6 +1552,13 @@ 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;
This probably only applies from 4.18 onwards, to test on older kernel try something
like this instead:
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 6996235..7925da9 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1606,7 +1606,11 @@ static void handle_port_status(struct xhci_hcd *xhci,
hcd = xhci_to_hcd(xhci);
if ((major_revision == 0x03) != (hcd->speed >= HCD_USB3))
hcd = xhci->shared_hcd;
-
+ if (!hcd) {
+ bogus_port_status = true;
+ goto cleanup;
+ }
if (major_revision == 0) {
xhci_warn(xhci, "Event for port %u not in "
"Extended Capabilities, ignoring.\n",
Jack, Peter, do these patches solve the remove issues you are seeing?
Thanks
-Mathias
