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

[Jonathan Cameron]

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 at huawei.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