[PATCH v4 1/6] arm_mpam: Fix the RIS index range check in mpam_ris_create_locked

[Yin Li]

The RIS selector field is defined as MPAMCFG_PART_SEL_RIS (bits 27:24),
which is 4 bits wide and gives valid indices 0..15. MPAM_MSC_MAX_NUM_RIS
is defined as 16, so the check should use >= to reject index 16 and
above. The previous > check incorrectly accepted index 16 as valid.

Fixes: 01fb4b822472 ("arm_mpam: Add the class and component structures for firmware described ris")
Signed-off-by: Yin Li <yin.li@xxxxxxxxxxxxxxxx>
Reviewed-by: Andre Przywara <andre.przywara@xxxxxxx>
Reviewed-by: Ben Horgan <ben.horgan@xxxxxxx>
---
 drivers/resctrl/mpam_devices.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index 48adc49b833c..347a5a6d6a1d 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -700,7 +700,7 @@ static int mpam_ris_create_locked(struct mpam_msc *msc, u8 ris_idx,
 
 	lockdep_assert_held(&mpam_list_lock);
 
-	if (ris_idx > MPAM_MSC_MAX_NUM_RIS)
+	if (ris_idx >= MPAM_MSC_MAX_NUM_RIS)
 		return -EINVAL;
 
 	if (test_and_set_bit(ris_idx, &msc->ris_idxs))

-- 
2.34.1