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authorJoe Lawrence <joe.lawrence@stratus.com>2014-09-10 15:07:50 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-09-10 13:32:35 -0700
commitc605f3cdff53a743f6d875b76956b239deca1272 (patch)
tree3ea0899daecae8401afa16e5feec9f0124257eae /drivers/usb/core
parenta9c54caa456dccba938005f6479892b589975e6a (diff)
downloadlinux-c605f3cdff53a743f6d875b76956b239deca1272.tar.bz2
usb: hub: take hub->hdev reference when processing from eventlist
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 <joe.lawrence@stratus.com> Suggested-by: David Bulkow <david.bulkow@stratus.com> for using kref Suggested-by: Alan Stern <stern@rowland.harvard.edu> for placement Acked-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core')
-rw-r--r--drivers/usb/core/hub.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 46f5161c7891..d481c99a20d7 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -5024,9 +5024,10 @@ 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",
@@ -5139,6 +5140,7 @@ 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) */