drm/amdgpu/mmhub4.1.0: add bounds checking for cid

commit 3cdd405 upstream.

The value should never exceed the array size as those
are the only values the hardware is expected to return,
but add checks anyway.

Reviewed-by: Benjamin Cheng <benjamin.cheng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 04f063d85090f5dd0c671010ce88ee49d9dcc8ed)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: alexdeucher

drivers/gpu/drm/amd/amdgpu/mmhub_v4_1_0.c

@@ -102,7 +102,8 @@ mmhub_v4_1_0_print_l2_protection_fault_status(struct amdgpu_device *adev,
 		status);
 	switch (amdgpu_ip_version(adev, MMHUB_HWIP, 0)) {
 	case IP_VERSION(4, 1, 0):
-		mmhub_cid = mmhub_client_ids_v4_1_0[cid][rw];
+		mmhub_cid = cid < ARRAY_SIZE(mmhub_client_ids_v4_1_0) ?
+			mmhub_client_ids_v4_1_0[cid][rw] : NULL;
 		break;
 	default:
 		mmhub_cid = NULL;