[lvc-project] [PATCH] ACPICA: fix largest possible resource descriptor index

[Fedor Pchelkin]

Hey Dmitry,

On Wed, 06. Aug 19:13, Dmitry Antipov wrote:
> ACPI_RESOURCE_NAME_LARGE_MAX should be equal to the last actually
> used resource descriptor index (ACPI_RESOURCE_NAME_CLOCK_INPUT).
> Otherwise 'resource_index' in 'acpi_ut_validate_resource()' may be
> clamped incorrectly and resulting value may issue an out-of-bounds
> access for 'acpi_gbl_resource_types' array. Compile tested only.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: 520d4a0ee5b6 ("ACPICA: add support for ClockInput resource (v6.5)")
> Signed-off-by: Dmitry Antipov <dmantipov at yandex.ru>
> ---

ACPICA patches should go through the separate Github project [1] first.
Please see [2] and [3] for examples.

[1]: https://github.com/acpica/acpica
[2]: https://docs.kernel.org/driver-api/acpi/linuxized-acpica.html
[3]: https://lore.kernel.org/acpica-devel/CAJZ5v0i7LYzF13M0qdeYWXZ7uO6HUpAS7pE5RJnOAJtKB8o88A@mail.gmail.com/T/#u

>  drivers/acpi/acpica/aclocal.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/acpi/acpica/aclocal.h b/drivers/acpi/acpica/aclocal.h
> index 0c41f0097e8d..f98640086f4e 100644
> --- a/drivers/acpi/acpica/aclocal.h
> +++ b/drivers/acpi/acpica/aclocal.h
> @@ -1141,7 +1141,7 @@ struct acpi_port_info {
>  #define ACPI_RESOURCE_NAME_PIN_GROUP_FUNCTION   0x91
>  #define ACPI_RESOURCE_NAME_PIN_GROUP_CONFIG     0x92
>  #define ACPI_RESOURCE_NAME_CLOCK_INPUT          0x93
> -#define ACPI_RESOURCE_NAME_LARGE_MAX            0x94
> +#define ACPI_RESOURCE_NAME_LARGE_MAX            0x93

I think some brief comment in the code explaining the reasoning for such a
definition for the MAX value would be worth it.

Though another way is to tweak the check inside acpi_ut_validate_resource()
to have '>=':

	if (resource_type > ACPI_RESOURCE_NAME_LARGE_MAX) {
		goto invalid_resource;
	}

Maybe that'd be a bit clearer?

Thanks!

>  
>  /*****************************************************************************
>   *
> -- 
> 2.50.1