Ignore invalid stream types when reading log update events

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/docker/LogUpdateEvent.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,8 @@
 import java.util.function.Consumer;
 import java.util.regex.Pattern;
 
+import org.springframework.util.StreamUtils;
+
 /**
  * An update event used to provide log updates.
  *
@@ -80,6 +82,16 @@ static void readAll(InputStream inputStream, Consumer<LogUpdateEvent> consumer)
 				consumer.accept(event);
 			}
 		}
+		catch (IllegalStateException ex) {
+			// Parsing has failed, abort further parsing
+			LogUpdateEvent abortedEvent = new LogUpdateEvent(StreamType.STD_ERR,
+					ex.getMessage().getBytes(StandardCharsets.UTF_8));
+			consumer.accept(abortedEvent);
+
+			// At this point, the inputStream is burned, consume it fully to prevent
+			// further processing
+			StreamUtils.drain(inputStream);
+		}
 		finally {
 			inputStream.close();
 		}
@@ -90,12 +102,21 @@ private static LogUpdateEvent read(InputStream inputStream) throws IOException {
 		if (header == null) {
 			return null;
 		}
-		StreamType streamType = StreamType.values()[header[0]];
+
+		// First byte denotes stream type. 0 = stdin, 1 = stdout, 2 = stderr
+		byte streamTypeId = header[0];
+		if (streamTypeId < 0 || streamTypeId >= StreamType.values().length) {
+			throw new IllegalStateException("Stream type is out of bounds. Must be >= 0 and < "
+					+ StreamType.values().length + ", but was " + streamTypeId + ". Will abort parsing.");
+		}
+
 		long size = 0;
 		for (int i = 0; i < 4; i++) {
 			size = (size << 8) + (header[i + 4] & 0xff);
 		}
 		byte[] payload = read(inputStream, size);
+
+		StreamType streamType = StreamType.values()[streamTypeId];
 		return new LogUpdateEvent(streamType, payload);
 	}
 

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/test/java/org/springframework/boot/buildpack/platform/docker/LogUpdateEventTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -53,6 +53,14 @@ void readAllWhenAnsiStreamReturnsEvents() throws Exception {
 		assertThat(events.get(2).toString()).isEqualTo("  OpenJDK JRE 11.0.5: Reusing cached layer");
 	}
 
+	@Test
+	void readSucceedsWhenStreamTypeIsInvalid() throws IOException {
+		List<LogUpdateEvent> events = readAll("log-update-event-invalid-stream-type.stream");
+		assertThat(events).hasSize(1);
+		assertThat(events.get(0).toString())
+				.isEqualTo("Stream type is out of bounds. Must be >= 0 and < 3, but was 3. Will abort parsing.");
+	}
+
 	private List<LogUpdateEvent> readAll(String name) throws IOException {
 		List<LogUpdateEvent> events = new ArrayList<>();
 		try (InputStream inputStream = getClass().getResourceAsStream(name)) {