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, 73 insertions, 0 deletions

diff --git a/tools/gpio/gpio-utils.h b/tools/gpio/gpio-utils.h
new file mode 100644
index 000000000..8af7c8ee1
--- /dev/null
+++ b/tools/gpio/gpio-utils.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * GPIO tools - utility helpers library for the GPIO tools
+ *
+ * Copyright (C) 2015 Linus Walleij
+ *
+ * Portions copied from iio_utils and lssio:
+ * Copyright (c) 2010 Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
+ * Copyright (c) 2008 Jonathan Cameron
+ * *
+ */
+#ifndef _GPIO_UTILS_H_
+#define _GPIO_UTILS_H_
+
+#include <stdbool.h>
+#include <string.h>
+#include <linux/types.h>
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+static inline int check_prefix(const char *str, const char *prefix)
+{
+	return strlen(str) > strlen(prefix) &&
+		strncmp(str, prefix, strlen(prefix)) == 0;
+}
+
+int gpiotools_request_line(const char *device_name,
+			   unsigned int *lines,
+			   unsigned int num_lines,
+			   struct gpio_v2_line_config *config,
+			   const char *consumer);
+int gpiotools_set_values(const int fd, struct gpio_v2_line_values *values);
+int gpiotools_get_values(const int fd, struct gpio_v2_line_values *values);
+int gpiotools_release_line(const int fd);
+
+int gpiotools_get(const char *device_name, unsigned int line);
+int gpiotools_gets(const char *device_name, unsigned int *lines,
+		   unsigned int num_lines, unsigned int *values);
+int gpiotools_set(const char *device_name, unsigned int line,
+		  unsigned int value);
+int gpiotools_sets(const char *device_name, unsigned int *lines,
+		   unsigned int num_lines, unsigned int *values);
+
+/* helper functions for gpio_v2_line_values bits */
+static inline void gpiotools_set_bit(__u64 *b, int n)
+{
+	*b |= _BITULL(n);
+}
+
+static inline void gpiotools_change_bit(__u64 *b, int n)
+{
+	*b ^= _BITULL(n);
+}
+
+static inline void gpiotools_clear_bit(__u64 *b, int n)
+{
+	*b &= ~_BITULL(n);
+}
+
+static inline int gpiotools_test_bit(__u64 b, int n)
+{
+	return !!(b & _BITULL(n));
+}
+
+static inline void gpiotools_assign_bit(__u64 *b, int n, bool value)
+{
+	if (value)
+		gpiotools_set_bit(b, n);
+	else
+		gpiotools_clear_bit(b, n);
+}
+
+#endif /* _GPIO_UTILS_H_ */