diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 442608220b5c8..4c97b0f44fce2 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -5,6 +5,7 @@
 #include <linux/list_sort.h>
 #include <linux/libnvdimm.h>
 #include <linux/module.h>
+#include <linux/nospec.h>
 #include <linux/mutex.h>
 #include <linux/ndctl.h>
 #include <linux/sysfs.h>
@@ -478,8 +479,11 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 		cmd_mask = nd_desc->cmd_mask;
 		if (cmd == ND_CMD_CALL && call_pkg->nd_family) {
 			family = call_pkg->nd_family;
-			if (!test_bit(family, &nd_desc->bus_family_mask))
+			if (family > NVDIMM_BUS_FAMILY_MAX ||
+			    !test_bit(family, &nd_desc->bus_family_mask))
 				return -EINVAL;
+			family = array_index_nospec(family,
+						    NVDIMM_BUS_FAMILY_MAX + 1);
 			dsm_mask = acpi_desc->family_dsm_mask[family];
 			guid = to_nfit_bus_uuid(family);
 		} else {