Commit 1f2235b8 authored Sep 12, 2012 by Alexander Shishkin Committed by Greg Kroah-Hartman Sep 12, 2012

usb: move children deallocation after quiescing the hub



Commit ff823c79 ("usb: move children
to struct usb_port") forgot to consider the hub_disconnect sequence,
which releases ports before quiescing the hub, which will lead to a
use-after-free, since hub_quiesce() will try to disconnect ports'
children, which are already deallocated. Simple modprobe dummy_hcd &&
rmmod dummy_hcd will illustrate the problem.

This patch moves deallocation of hub's ports after hub_quiesce() call
in hub_disconnect().

Cc: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 58efc77c

drivers/usb/core/hub.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -1584,9 +1584,6 @@ static void hub_disconnect(struct usb_interface *intf)
		struct usb_device *hdev = interface_to_usbdev(intf);
		int i;

		for (i = 0; i < hdev->maxchild; i++)
		usb_hub_remove_port_device(hub, i + 1);

		/* Take the hub off the event list and don't let it be added again */
		spin_lock_irq(&hub_event_lock);
		if (!list_empty(&hub->event_list)) {
		@@ -1601,6 +1598,9 @@ static void hub_disconnect(struct usb_interface *intf)
		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);
		hub->hdev->maxchild = 0;

		if (hub->hdev->speed == USB_SPEED_HIGH)

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