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, 54 insertions, 0 deletions

diff --git a/tools/lib/slab.c b/tools/lib/slab.c
new file mode 100644
index 000000000..981a21404
--- /dev/null
+++ b/tools/lib/slab.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdio.h>
+#include <string.h>
+
+#include <urcu/uatomic.h>
+#include <linux/slab.h>
+#include <malloc.h>
+#include <linux/gfp.h>
+
+int kmalloc_nr_allocated;
+int kmalloc_verbose;
+
+void *kmalloc(size_t size, gfp_t gfp)
+{
+	void *ret;
+
+	if (!(gfp & __GFP_DIRECT_RECLAIM))
+		return NULL;
+
+	ret = malloc(size);
+	uatomic_inc(&kmalloc_nr_allocated);
+	if (kmalloc_verbose)
+		printf("Allocating %p from malloc\n", ret);
+	if (gfp & __GFP_ZERO)
+		memset(ret, 0, size);
+	return ret;
+}
+
+void kfree(void *p)
+{
+	if (!p)
+		return;
+	uatomic_dec(&kmalloc_nr_allocated);
+	if (kmalloc_verbose)
+		printf("Freeing %p to malloc\n", p);
+	free(p);
+}
+
+void *kmalloc_array(size_t n, size_t size, gfp_t gfp)
+{
+	void *ret;
+
+	if (!(gfp & __GFP_DIRECT_RECLAIM))
+		return NULL;
+
+	ret = calloc(n, size);
+	uatomic_inc(&kmalloc_nr_allocated);
+	if (kmalloc_verbose)
+		printf("Allocating %p from calloc\n", ret);
+	if (gfp & __GFP_ZERO)
+		memset(ret, 0, n * size);
+	return ret;
+}