[PATCH 4.14 041/125] ACPI: Add out of bounds and numa_off protections to pxm_to_node()

[Greg Kroah-Hartman]

From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

[ Upstream commit 8a3decac087aa897df5af04358c2089e52e70ac4 ]

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@xxxxxxxxxx>
Reviewed-by: Barry Song <song.bao.hua@xxxxxxxxxxxxx>
Reviewed-by: Hanjun Guo <guohanjun@xxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/acpi/numa.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/numa.c b/drivers/acpi/numa.c
index a7907b58562a7..986712fe2a71c 100644
--- a/drivers/acpi/numa.c
+++ b/drivers/acpi/numa.c
@@ -46,7 +46,7 @@ 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];
 }
-- 
2.27.0