drm/amdgpu/mmhub3.0.2: add bounds checking for cid

commit e5e6d67 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 1441f52c7f6ae6553664aa9e3e4562f6fc2fe8ea)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: alexdeucher

drivers/gpu/drm/amd/amdgpu/mmhub_v3_0_2.c

@@ -108,7 +108,8 @@ mmhub_v3_0_2_print_l2_protection_fault_status(struct amdgpu_device *adev,
 		"MMVM_L2_PROTECTION_FAULT_STATUS:0x%08X\n",
 		status);
 
-	mmhub_cid = mmhub_client_ids_v3_0_2[cid][rw];
+	mmhub_cid = cid < ARRAY_SIZE(mmhub_client_ids_v3_0_2) ?
+		mmhub_client_ids_v3_0_2[cid][rw] : NULL;
 	dev_err(adev->dev, "\t Faulty UTCL2 client ID: %s (0x%x)\n",
 		mmhub_cid ? mmhub_cid : "unknown", cid);
 	dev_err(adev->dev, "\t MORE_FAULTS: 0x%lx\n",