Re: [PATCH v2 02/37] PNPACPI: Fix device ref leaking in acpi_pnp_match

From: Bjorn Helgaas
Date: Mon Mar 12 2012 - 22:41:21 EST


On Sat, Mar 10, 2012 at 12:00 AM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> During testing pci root bus removal, found some root bus bridge is not freed.
>
> If booting with pnpacpi=off, those hostbridge could be freed without problem.
>
> It turns out that some devices reference are not released during acpi_pnp_match.
>
> That match should not hold one device ref during every calling.
>
> Add put_device calling before returning.

Changelog doesn't fit in 80 columns when using "git log". I mentioned
this before; please try it yourself.

> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxx
> Cc: Len Brown <lenb@xxxxxxxxxx>
> Cc: Adam Belay <abelay@xxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: linux-acpi@xxxxxxxxxxxxxxx
> ---
>  drivers/pnp/pnpacpi/core.c |    7 ++++++-
>  1 files changed, 6 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/pnp/pnpacpi/core.c b/drivers/pnp/pnpacpi/core.c
> index b00c176..d21e8f5 100644
> --- a/drivers/pnp/pnpacpi/core.c
> +++ b/drivers/pnp/pnpacpi/core.c
> @@ -321,9 +321,14 @@ static int __init acpi_pnp_match(struct device *dev, void *_pnp)
>  {
>        struct acpi_device *acpi = to_acpi_device(dev);
>        struct pnp_dev *pnp = _pnp;
> +       struct device *physical_device;
> +
> +       physical_device = acpi_get_physical_device(acpi->handle);
> +       if (physical_device)
> +               put_device(physical_device);
>
>        /* true means it matched */
> -       return !acpi_get_physical_device(acpi->handle)
> +       return !physical_device
>            && compare_pnp_id(pnp->id, acpi_device_hid(acpi));
>  }
>
> --
> 1.7.7
>
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