[PATCH] PCI: hv: Fix a use-after-free bug in hv_eject_device_work()

[Dexuan Cui]

> From: Michael Kelley <mikelley at microsoft.com>
> > @@ -1880,6 +1880,7 @@ static void hv_pci_devices_present(struct
> hv_pcibus_device
> > *hbus,
> >  static void hv_eject_device_work(struct work_struct *work)
> >  {
> >  	struct pci_eject_response *ejct_pkt;
> > +	struct hv_pcibus_device *hbus;
> >  	struct hv_pci_dev *hpdev;
> >  	struct pci_dev *pdev;
> >  	unsigned long flags;
> > @@ -1890,6 +1891,7 @@ static void hv_eject_device_work(struct
> work_struct *work)
> >  	} ctxt;
> >
> >  	hpdev = container_of(work, struct hv_pci_dev, wrk);
> > +	hbus = hpdev->hbus;
> 
> In the lines of code following this new assignment, there are four uses of
> hpdev->hbus besides the one at the bottom of the function that causes the
> use-after-free error.  With 'hbus' now available as a local variable, it looks
> rather strange to have those other places still using hpdev->hbus.  I'm
> thinking
> they should be shortened to just 'hbus' for consistency, even though such
> changes aren't directly related to fixing the bug.
> 
> Michael
 
Ok, let me post a v2 for this.

Thanks,
Dexuan