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, 55 insertions, 0 deletions

diff --git a/io_uring/wait.h b/io_uring/wait.h
new file mode 100644
index 000000000..b7b9c46b1
--- /dev/null
+++ b/io_uring/wait.h
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef IOU_WAIT_H
+#define IOU_WAIT_H
+
+#include <linux/io_uring_types.h>
+
+/*
+ * ->cq_wait_nr is armed with the number of lazy task_work adds the waiter
+ * still needs, and counted down by the add side, with the add reaching zero
+ * issuing the (single) wake up for this wait cycle. Zero and below means no
+ * wake up is to be issued: IO_CQ_WAKE_INIT when no task is waiting (also
+ * what a forced wake up resets it to when claiming one), zero once the
+ * countdown has fired.
+ */
+#define IO_CQ_WAKE_INIT		(-1)
+
+struct ext_arg {
+	size_t argsz;
+	struct timespec64 ts;
+	const sigset_t __user *sig;
+	ktime_t min_time;
+	bool ts_set;
+	bool iowait;
+};
+
+int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, u32 flags,
+		   struct ext_arg *ext_arg);
+int io_run_task_work_sig(struct io_ring_ctx *ctx);
+void io_cqring_do_overflow_flush(struct io_ring_ctx *ctx);
+void io_cqring_overflow_flush_locked(struct io_ring_ctx *ctx);
+
+static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx)
+{
+	struct io_rings *rings = io_get_rings(ctx);
+	return ctx->cached_cq_tail - READ_ONCE(rings->cq.head);
+}
+
+static inline unsigned int __io_cqring_events_user(struct io_ring_ctx *ctx)
+{
+	struct io_rings *rings = io_get_rings(ctx);
+
+	return READ_ONCE(rings->cq.tail) - READ_ONCE(rings->cq.head);
+}
+
+/*
+ * Reads the tail/head of the CQ ring while providing an acquire ordering,
+ * see comment at top of io_uring.c.
+ */
+static inline unsigned io_cqring_events(struct io_ring_ctx *ctx)
+{
+	smp_rmb();
+	return __io_cqring_events(ctx);
+}
+
+#endif