Re: [PATCH] xhci: fix memleak on setup address fails.

[Mathias Nyman]

On 26.8.2019 9.41, Ikjoon Jang wrote:
> On Wed, Aug 14, 2019 at 9:57 PM Mathias Nyman
> <mathias.nyman@xxxxxxxxxxxxxxx> wrote:
> > On 11.8.2019 11.22, Ikjoon Jang wrote:
> > > Xhci re-enables a slot on transaction error in set_address using
> > > xhci_disable_slot() + xhci_alloc_dev().
> > >
> > > But in this case, xhci_alloc_dev() creates debugfs entries upon an
> > > existing device without cleaning up old entries, thus memory leaks.
> > >
> > > So this patch simply moves calling xhci_debugfs_free_dev() from
> > > xhci_free_dev() to xhci_disable_slot().
> >
> > Othwerwise this looks good, but xhci_alloc_dev() will call xhci_disable_slot()
> > in some failure cases before the slot debugfs entry is created.
> >
> > In these cases xhci_debugfs_remove_slot() will be called without
> > xhci_debugfs_create_slot() ever being called.
> >
> > This might not be an issue as xhci_debugfs_remove_slot() checks
> > if (!dev || !dev->debugfs_private) before doing anything, but should
> > be checked out.
>
> I checked out the case by adding simple fault injection on xhci_alloc_dev(),
> to simulate xhci_debugfs_remove_slot() can be called without
> xhci_debugfs_create_slot() being called.

Thanks, patch sent forward

-Mathias