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, 48 insertions, 0 deletions

diff --git a/block/partitions/ultrix.c b/block/partitions/ultrix.c
new file mode 100644
index 000000000..b4b9ddc57
--- /dev/null
+++ b/block/partitions/ultrix.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  fs/partitions/ultrix.c
+ *
+ *  Code extracted from drivers/block/genhd.c
+ *
+ *  Re-organised Jul 1999 Russell King
+ */
+
+#include "check.h"
+
+int ultrix_partition(struct parsed_partitions *state)
+{
+	int i;
+	Sector sect;
+	unsigned char *data;
+	struct ultrix_disklabel {
+		s32	pt_magic;	/* magic no. indicating part. info exits */
+		s32	pt_valid;	/* set by driver if pt is current */
+		struct  pt_info {
+			s32		pi_nblocks; /* no. of sectors */
+			u32		pi_blkoff;  /* block offset for start */
+		} pt_part[8];
+	} *label;
+
+#define PT_MAGIC	0x032957	/* Partition magic number */
+#define PT_VALID	1		/* Indicates if struct is valid */
+
+	data = read_part_sector(state, (16384 - sizeof(*label))/512, &sect);
+	if (!data)
+		return -1;
+	
+	label = (struct ultrix_disklabel *)(data + 512 - sizeof(*label));
+
+	if (label->pt_magic == PT_MAGIC && label->pt_valid == PT_VALID) {
+		for (i=0; i<8; i++)
+			if (label->pt_part[i].pi_nblocks)
+				put_partition(state, i+1, 
+					      label->pt_part[i].pi_blkoff,
+					      label->pt_part[i].pi_nblocks);
+		put_dev_sector(sect);
+		seq_buf_puts(&state->pp_buf, "\n");
+		return 1;
+	} else {
+		put_dev_sector(sect);
+		return 0;
+	}
+}