From: Joe Lawrence Date: Wed, 10 Sep 2014 19:07:50 +0000 (-0400) Subject: usb: hub: take hub->hdev reference when processing from eventlist X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3f6622c77fe9a0bc5ed668e5e9b03944e3cd80a4;p=karo-tx-linux.git usb: hub: take hub->hdev reference when processing from eventlist commit c605f3cdff53a743f6d875b76956b239deca1272 upstream. During surprise device hotplug removal tests, it was observed that hub_events may try to call usb_lock_device on a device that has already been freed. Protect the usb_device by taking out a reference (under the hub_event_lock) when hub_events pulls it off the list, returning the reference after hub_events is finished using it. Signed-off-by: Joe Lawrence Suggested-by: David Bulkow for using kref Suggested-by: Alan Stern for placement Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 6650df70bb35..263612ce1f62 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -4764,9 +4764,10 @@ static void hub_events(void) hub = list_entry(tmp, struct usb_hub, event_list); kref_get(&hub->kref); + hdev = hub->hdev; + usb_get_dev(hdev); spin_unlock_irq(&hub_event_lock); - hdev = hub->hdev; hub_dev = hub->intfdev; intf = to_usb_interface(hub_dev); dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n", @@ -4979,6 +4980,7 @@ static void hub_events(void) usb_autopm_put_interface(intf); loop_disconnected: usb_unlock_device(hdev); + usb_put_dev(hdev); kref_put(&hub->kref, hub_release); } /* end while (1) */