patch "xhci: handle port status events for removed USB3 hcd" added to usb-linus

patch "xhci: handle port status events for removed USB3 hcd" added to usb-linus

[gregkh]

This is a note to let you know that I've just added the patch titled

    xhci: handle port status events for removed USB3 hcd

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


>From 1245374e9b8340fc255fd51b2015173a83050d03 Mon Sep 17 00:00:00 2001
From: Mathias Nyman <mathias.nyman@linux.intel.com>
Date: Fri, 9 Nov 2018 17:21:18 +0200
Subject: 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: <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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 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 a8d92c90fb58..80d464ea5a9a 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;
-- 
2.19.1