xhci: Fix xhci debugfs NULL pointer dereference in resume from hibernate

Free the virt_device and its debugfs_private member together.

When resuming from hibernate the .free_dev callback unconditionally
freed the debugfs_private member, but could leave virt_device intact.

This triggered a NULL pointer dereference after resume when usbmuxd
sent a USBDEVFS_SETCONFIGURATION ioctl to a device, trying to add a
endpoint debugfs entry to a already freed debugfs_private pointer.

Fixes: 02b6fdc2a153 ("usb: xhci: Add debugfs interface for xHCI driver")
Reported-by: Alexander Kappner <agk@godking.net>
Tested-by: Alexander Kappner <agk@godking.net>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 2424d30..da6dbe3 100644 (file)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3525,8 +3525,6 @@ static void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev)
        struct xhci_slot_ctx *slot_ctx;
        int i, ret;
 
-       xhci_debugfs_remove_slot(xhci, udev->slot_id);
-
 #ifndef CONFIG_USB_DEFAULT_PERSIST
        /*
         * We called pm_runtime_get_noresume when the device was attached.
@@ -3555,8 +3553,10 @@ static void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev)
        }
 
        ret = xhci_disable_slot(xhci, udev->slot_id);
-       if (ret)
+       if (ret) {
+               xhci_debugfs_remove_slot(xhci, udev->slot_id);
                xhci_free_virt_device(xhci, udev->slot_id);
+       }
 }
 
 int xhci_disable_slot(struct xhci_hcd *xhci, u32 slot_id)