regulator: of: Implement the unwind path of of_regulator_match()

[ Upstream commit dddca3b ]

of_regulator_match() does not release the OF node reference in the error
path, resulting in an OF node leak. Therefore, call of_node_put() on the
obtained nodes before returning the EINVAL error.

Since it is possible that some drivers call this function and do not
exit on failure, such as s2mps11_pmic_driver, clear the init_data and
of_node in the error path.

This was reported by an experimental verification tool that I am
developing. As I do not have access to actual devices nor the QEMU board
configuration to test drivers that call this function, no runtime test
was able to be performed.

Fixes: 1c8fa58 ("regulator: Add generic DT parsing for regulators")
Signed-off-by: Joe Hattori <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
(cherry picked from commit c22e13ecc9ca7d23423e28d70170b01d991281a4)

Author: joehattori

drivers/regulator/of_regulator.c

@@ -435,7 +435,7 @@ int of_regulator_match(struct device *dev, struct device_node *node,
 					"failed to parse DT for regulator %pOFn\n",
 					child);
 				of_node_put(child);
-				return -EINVAL;
+				goto err_put;
 			}
 			match->of_node = of_node_get(child);
 			count++;
@@ -444,6 +444,18 @@ int of_regulator_match(struct device *dev, struct device_node *node,
 	}
 
 	return count;
+
+err_put:
+	for (i = 0; i < num_matches; i++) {
+		struct of_regulator_match *match = &matches[i];
+
+		match->init_data = NULL;
+		if (match->of_node) {
+			of_node_put(match->of_node);
+			match->of_node = NULL;
+		}
+	}
+	return -EINVAL;
 }
 EXPORT_SYMBOL_GPL(of_regulator_match);