AW: [Patch v4] usb: hcd: fix use-after-free on driver removal

["Schmid, Carsten" <Carsten_Schmid@mentor.com>]

> > On driver removal, the platform_device_unregister call
> > attached through devm_add_action_or_reset was executed
> > after usb_hcd_pci_remove.
> > This lead to a use-after-free for the iomem resource of
> > the xhci-ext-caps driver in the platform removal
> > because the parent of the resource was freed earlier.
> >
> > Fix this by using devm for hcd-pci created resources.
> > This simplifies error handling on driver initialisation
> > and fixes the removal sequence.
> >
> > Signed-off-by: Carsten Schmid <carsten_schmid@mentor.com>
> > Tested-by: Carsten Schmid <carsten_schmid@mentor.com>
> > ---
> 
> Thanks, code looks good to me.
> 
> But as this is no longer a xhci specific fix I'm not sure if this
> commit message is generic enough.
> 
> Could be worth explaining that using managed device resources
> in usb_hcd_pci_probe() allows devm usage for resource subranges, such
> as the mmio resource for the platform device created to control host/device
> mode mux, which is a xhci extended capability, and sits inside the xhci mmio
> region.
> 
> If managed device resources are not used then "parent" resource
> is released before subrange at driver removal as .remove callback is
> called before the devres list of resources for this device is walked
> and released
> 
> -Mathias
> 
I agree, this covers more than the fix i originally have in mind.

May i use/cite your "could be worth explaining" above for the commit message?
(of course, a bit adapted :-) )

And: i would like replace the commit title again to read:
usb: hcd: use managed device resources

Ok for you?

BR
Carsten