drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform devicegrafted

platform_device_register_data() can fail and return an ERR_PTR, but the
return value is used without checking, leading to an invalid pointer
being stored in ddp_comp[].dev and passed to component_match_add() and
mtk_ddp_comp_init(), which could result in a kernel crash.

Add an IS_ERR() check to jump to the error handling path on failure.

Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195")
Cc: stable@vger.kernel.org
Signed-off-by: Haojie Li <lihaojie@kylinos.cn>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

1 files changed, 64 insertions, 0 deletions

diff --git a/tools/crypto/ccp/dbc.py b/tools/crypto/ccp/dbc.py
new file mode 100644
index 000000000..2b91415b1
--- /dev/null
+++ b/tools/crypto/ccp/dbc.py
@@ -0,0 +1,64 @@
+#!/usr/bin/python3
+# SPDX-License-Identifier: GPL-2.0
+
+import ctypes
+import os
+
+DBC_UID_SIZE = 16
+DBC_NONCE_SIZE = 16
+DBC_SIG_SIZE = 32
+
+PARAM_GET_FMAX_CAP = (0x3,)
+PARAM_SET_FMAX_CAP = (0x4,)
+PARAM_GET_PWR_CAP = (0x5,)
+PARAM_SET_PWR_CAP = (0x6,)
+PARAM_GET_GFX_MODE = (0x7,)
+PARAM_SET_GFX_MODE = (0x8,)
+PARAM_GET_CURR_TEMP = (0x9,)
+PARAM_GET_FMAX_MAX = (0xA,)
+PARAM_GET_FMAX_MIN = (0xB,)
+PARAM_GET_SOC_PWR_MAX = (0xC,)
+PARAM_GET_SOC_PWR_MIN = (0xD,)
+PARAM_GET_SOC_PWR_CUR = (0xE,)
+
+DEVICE_NODE = "/dev/dbc"
+
+lib = ctypes.CDLL("./dbc_library.so", mode=ctypes.RTLD_GLOBAL)
+
+
+def handle_error(code):
+    raise OSError(code, os.strerror(code))
+
+
+def get_nonce(device, signature):
+    if not device:
+        raise ValueError("Device required")
+    buf = ctypes.create_string_buffer(DBC_NONCE_SIZE)
+    ret = lib.get_nonce(device.fileno(), ctypes.byref(buf), signature)
+    if ret:
+        handle_error(ret)
+    return buf.value
+
+
+def set_uid(device, new_uid, signature):
+    if not signature:
+        raise ValueError("Signature required")
+    if not new_uid:
+        raise ValueError("UID required")
+    ret = lib.set_uid(device.fileno(), new_uid, signature)
+    if ret:
+        handle_error(ret)
+    return True
+
+
+def process_param(device, message, signature, data=None):
+    if not signature:
+        raise ValueError("Signature required")
+    if type(message) != tuple:
+        raise ValueError("Expected message tuple")
+    arg = ctypes.c_int(data if data else 0)
+    sig = ctypes.create_string_buffer(signature, len(signature))
+    ret = lib.process_param(device.fileno(), message[0], ctypes.pointer(sig), ctypes.pointer(arg))
+    if ret:
+        handle_error(ret)
+    return arg.value, sig.value