RE: [PATCH v2 1/6] ACPI: Add out of bounds and numa_off protections to pxm_to_node

["Song Bao Hua (Barry Song)" <song.bao.hua@hisilicon.com>]

> -----Original Message-----
> From: Jonathan Cameron
> Sent: Saturday, July 18, 2020 6:00 AM
> To: linux-mm@kvack.org; linux-acpi@vger.kernel.org;
> linux-arm-kernel@lists.infradead.org; x86@kernel.org
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>; Bjorn Helgaas
> <bhelgaas@google.com>; linux-pci@vger.kernel.org; martin@geanix.com; Ingo
> Molnar <mingo@redhat.com>; linux-ia64@vger.kernel.org; Tony Luck
> <tony.luck@intel.com>; Fenghua Yu <fenghua.yu@intel.com>; Thomas
> Gleixner <tglx@linutronix.de>; Linuxarm <linuxarm@huawei.com>; Dan
> Williams <dan.j.williams@intel.com>; Song Bao Hua (Barry Song)
> <song.bao.hua@hisilicon.com>; Jonathan Cameron
> <jonathan.cameron@huawei.com>
> Subject: [PATCH v2 1/6] ACPI: Add out of bounds and numa_off protections to
> pxm_to_node
> 
> The function should check the validity of the pxm value before using
> it to index the pxm_to_node_map array.
> 
> Whilst hardening this code may be good in general, the main intent
> here is to enable following patches that use this function to replace
> acpi_map_pxm_to_node for non SRAT usecases which should return
> NO_NUMA_NODE for PXM entries not matching with those in SRAT.
> 
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Reviewed-by: Barry Song <song.bao.hua@hisilicon.com>

> ---
>  drivers/acpi/numa/srat.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
> index 5be5a977da1b..8ef44ee0d76b 100644
> --- a/drivers/acpi/numa/srat.c
> +++ b/drivers/acpi/numa/srat.c
> @@ -31,7 +31,7 @@ int acpi_numa __initdata;
> 
>  int pxm_to_node(int pxm)
>  {
> -	if (pxm < 0)
> +	if (pxm < 0 || pxm >= MAX_PXM_DOMAINS || numa_off)
>  		return NUMA_NO_NODE;
>  	return pxm_to_node_map[pxm];
>  }
> --
> 2.19.1