Re: [PATCH 2/2] ACPI / bind: Use (put|get)_device() on ACPI deviceobjects too

From: Greg Kroah-Hartman
Date: Wed Nov 13 2013 - 21:44:01 EST


On Thu, Nov 14, 2013 at 12:26:47AM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> When associating a "physical" device with an ACPI device object
> acpi_bind_one() only uses get_device() to increment the reference
> counter of the former, but there is no reason not to do that with
> the latter too. Among other things, that may help to avoid
> use-after-free when an ACPI device object is freed without calling
> acpi_unbind_one() for all "physical" devices associated with it
> (that only can happen in buggy code, but then it's better if the
> kernel doesn't crash as a result of a bug).
>
> For this reason, modify acpi_bind_one() to apply get_device() to
> the ACPI device object too and update acpi_unbind_one() to drop
> that reference using put_device() as appropriate.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/