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USB: hub: change the locking in hub_activate
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The locking in hub_activate() is not adequate to provide full mutual
exclusion with hub_quiesce().  The subroutine locks the hub's
usb_interface, but the callers of hub_quiesce() (such as
hub_pre_reset() and hub_event()) hold the lock to the hub's
usb_device.

This patch changes hub_activate() to make it acquire the same lock as
those other routines.

Signed-off-by: Alan Stern <[email protected]>
CC: <[email protected]> #4.4+
Signed-off-by: Greg Kroah-Hartman <[email protected]>
AlanStern authored and gregkh committed Aug 9, 2016

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axelboc Axel Bocciarelli
1 parent ca5cbc8 commit 07d316a
Showing 1 changed file with 3 additions and 3 deletions.
6 changes: 3 additions & 3 deletions drivers/usb/core/hub.c
Original file line number Diff line number Diff line change
@@ -1052,7 +1052,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)

/* Continue a partial initialization */
if (type == HUB_INIT2 || type == HUB_INIT3) {
device_lock(hub->intfdev);
device_lock(&hdev->dev);

/* Was the hub disconnected while we were waiting? */
if (hub->disconnected)
@@ -1259,7 +1259,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
queue_delayed_work(system_power_efficient_wq,
&hub->init_work,
msecs_to_jiffies(delay));
device_unlock(hub->intfdev);
device_unlock(&hdev->dev);
return; /* Continues at init3: below */
} else {
msleep(delay);
@@ -1282,7 +1282,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
/* Allow autosuspend if it was suppressed */
disconnected:
usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
device_unlock(hub->intfdev);
device_unlock(&hdev->dev);
}

kref_put(&hub->kref, hub_release);

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