[PATCH v2] media: adv748x: Fix endpoint reference leaks on probe failure

[Ruoyu Wang]

adv748x_parse_dt() takes an extra reference for every endpoint saved in
state->endpoints. If parsing later fails, adv748x_probe() skips
adv748x_dt_cleanup(), so the saved references remain held. A CSI-2 lane
parsing error also returns from for_each_endpoint_of_node() without
dropping the iterator's reference.

Save the endpoint reference only after lane parsing succeeds. Drop the
iterator reference before returning a lane parsing error and route all
parse failures through the endpoint cleanup path to release any saved
references. This retains the endpoints only for a successful probe.

This issue was found by a static analysis checker and confirmed by
manual source review.

Fixes: 6a18865da8e3 ("media: i2c: adv748x: store number of CSI-2 lanes described in device tree")
Fixes: eccf442ce156 ("media: i2c: adv748x: Support probing a single output")
Suggested-by: Hans Verkuil <hverkuil+cisco@xxxxxxxxxx>
Signed-off-by: Ruoyu Wang <ruoyuw560@xxxxxxxxx>
---
Changes in v2:
- Move of_node_get() and the assignment to state->endpoints[ep.port]
  after successful lane parsing, as suggested by Hans Verkuil.

v1: https://lore.kernel.org/r/20260814134106.1387486-1-ruoyuw560@xxxxxxxxx/

 drivers/media/i2c/adv748x/adv748x-core.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/media/i2c/adv748x/adv748x-core.c b/drivers/media/i2c/adv748x/adv748x-core.c
index 3eb6d5e8f0826..70594d0018048 100644
--- a/drivers/media/i2c/adv748x/adv748x-core.c
+++ b/drivers/media/i2c/adv748x/adv748x-core.c
@@ -675,9 +675,6 @@ static int adv748x_parse_dt(struct adv748x_state *state)
 			continue;
 		}
 
-		of_node_get(ep_np);
-		state->endpoints[ep.port] = ep_np;
-
 		/*
 		 * At least one input endpoint and one output endpoint shall
 		 * be defined.
@@ -689,8 +686,13 @@ static int adv748x_parse_dt(struct adv748x_state *state)
 
 		/* Store number of CSI-2 lanes used for TXA and TXB. */
 		ret = adv748x_parse_csi2_lanes(state, ep.port, ep_np);
-		if (ret)
+		if (ret) {
+			of_node_put(ep_np);
 			return ret;
+		}
+
+		of_node_get(ep_np);
+		state->endpoints[ep.port] = ep_np;
 	}
 
 	return in_found && out_found ? 0 : -ENODEV;
@@ -739,7 +741,7 @@ static int adv748x_probe(struct i2c_client *client)
 	ret = adv748x_parse_dt(state);
 	if (ret) {
 		adv_err(state, "Failed to parse device tree");
-		goto err_free_mutex;
+		goto err_cleanup_dt;
 	}
 
 	/* Configure IO Regmap region */
@@ -809,7 +811,6 @@ static int adv748x_probe(struct i2c_client *client)
 	adv748x_unregister_clients(state);
 err_cleanup_dt:
 	adv748x_dt_cleanup(state);
-err_free_mutex:
 	mutex_destroy(&state->mutex);
 
 	return ret;

-- 
2.34.1