RE: [PATCH] usb/core: fix NULL pointer dereference inrecursively_mark_NOTATTACHED

From: Du, ChangbinX
Date: Wed Dec 25 2013 - 21:12:38 EST


> On Tue, 24 Dec 2013, Alan Stern wrote:
> I think this will fix it. Take a close look and do some careful testing.
>
> Alan Stern
>
> Index: usb-3.13/drivers/usb/core/hub.c
> ==========================================================
> =========
> --- usb-3.13.orig/drivers/usb/core/hub.c
> +++ usb-3.13/drivers/usb/core/hub.c
> @@ -1622,11 +1622,14 @@ static void hub_disconnect(struct usb_in
> hub->error = 0;
> hub_quiesce(hub, HUB_DISCONNECT);
>
> - usb_set_intfdata (intf, NULL);
> -
> for (i = 0; i < hdev->maxchild; i++)
> usb_hub_remove_port_device(hub, i + 1);
> +
> + /* Avoid races with recursively_mark_NOTATTACHED() */
> + spin_lock_irq(&device_state_lock);
> hub->hdev->maxchild = 0;
> + usb_set_intfdata(intf, NULL);
> + spin_unlock_irq(&device_state_lock);
>
> if (hub->hdev->speed == USB_SPEED_HIGH)
> highspeed_hubs--;
>

Sorry for late response. Agree with you. I will test your patch carefully and
let you know the result. Thanks!

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