diff --git a/spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/nio/file/NestedByteChannel.java b/spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/nio/file/NestedByteChannel.java
index e41b27fd65..3e51924ed3 100644
--- a/spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/nio/file/NestedByteChannel.java
+++ b/spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/nio/file/NestedByteChannel.java
@@ -81,11 +81,16 @@ class NestedByteChannel implements SeekableByteChannel {
 	@Override
 	public int read(ByteBuffer dst) throws IOException {
 		assertNotClosed();
-		int count = this.resources.getData().read(dst, this.position);
-		if (count > 0) {
+		int total = 0;
+		while (dst.remaining() > 0) {
+			int count = this.resources.getData().read(dst, this.position);
+			if (count <= 0) {
+				return (total != 0) ? 0 : count;
+			}
+			total += count;
 			this.position += count;
 		}
-		return count;
+		return total;
 	}
 
 	@Override
diff --git a/spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/nio/file/NestedByteChannelTests.java b/spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/nio/file/NestedByteChannelTests.java
index d9ff2e83a1..7fef82d351 100644
--- a/spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/nio/file/NestedByteChannelTests.java
+++ b/spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/nio/file/NestedByteChannelTests.java
@@ -17,11 +17,16 @@
 package org.springframework.boot.loader.nio.file;
 
 import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
 import java.lang.ref.Cleaner.Cleanable;
 import java.nio.ByteBuffer;
 import java.nio.channels.ClosedChannelException;
 import java.nio.channels.NonWritableChannelException;
+import java.util.jar.JarEntry;
+import java.util.jar.JarOutputStream;
+import java.util.zip.CRC32;
+import java.util.zip.ZipEntry;
 
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
@@ -32,6 +37,7 @@ import org.mockito.ArgumentCaptor;
 import org.springframework.boot.loader.ref.Cleaner;
 import org.springframework.boot.loader.testsupport.TestJar;
 import org.springframework.boot.loader.zip.AssertFileChannelDataBlocksClosed;
+import org.springframework.boot.loader.zip.FileChannelDataBlockManagedFileChannel;
 import org.springframework.boot.loader.zip.ZipContent;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -117,6 +123,36 @@ class NestedByteChannelTests {
 		assertThat(dst.array()).isNotEqualTo(ByteBuffer.allocate(10).array());
 	}
 
+	@Test // gh-38592
+	void readReadsAsManyBytesAsPossible() throws Exception {
+		// ZipFileSystem checks that the number of bytes read matches an expected value
+		// ...if (readFullyAt(cen, 0, cen.length, cenpos) != end.cenlen + ENDHDR)
+		// but the readFullyAt assumes that all remaining bytes are attempted to be read
+		// This doesn't seem to exactly match the contract of ReadableByteChannel.read
+		// which states "A read operation might not fill the buffer, and in fact it might
+		// not read any bytes at all", but we need to match ZipFileSystem's expectations
+		int size = FileChannelDataBlockManagedFileChannel.BUFFER_SIZE * 2;
+		byte[] data = new byte[size];
+		this.file = new File(this.temp, "testread.jar");
+		FileOutputStream fileOutputStream = new FileOutputStream(this.file);
+		try (JarOutputStream jarOutputStream = new JarOutputStream(fileOutputStream)) {
+			JarEntry nestedEntry = new JarEntry("data");
+			nestedEntry.setSize(size);
+			nestedEntry.setCompressedSize(size);
+			CRC32 crc32 = new CRC32();
+			crc32.update(data);
+			nestedEntry.setCrc(crc32.getValue());
+			nestedEntry.setMethod(ZipEntry.STORED);
+			jarOutputStream.putNextEntry(nestedEntry);
+			jarOutputStream.write(data);
+			jarOutputStream.closeEntry();
+		}
+		this.channel = new NestedByteChannel(this.file.toPath(), null);
+		ByteBuffer buffer = ByteBuffer.allocate((int) this.file.length());
+		assertThat(this.channel.read(buffer)).isEqualTo(buffer.capacity());
+		assertThat(this.file).binaryContent().isEqualTo(buffer.array());
+	}
+
 	@Test
 	void writeThrowsException() {
 		assertThatExceptionOfType(NonWritableChannelException.class)
diff --git a/spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/zip/FileChannelDataBlockManagedFileChannel.java b/spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/zip/FileChannelDataBlockManagedFileChannel.java
new file mode 100644
index 0000000000..6e945dbd43
--- /dev/null
+++ b/spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/zip/FileChannelDataBlockManagedFileChannel.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2012-2023 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.loader.zip;
+
+import org.springframework.boot.loader.zip.FileChannelDataBlock.ManagedFileChannel;
+
+/**
+ * Test access to {@link ManagedFileChannel} details.
+ *
+ * @author Phillip Webb
+ */
+public final class FileChannelDataBlockManagedFileChannel {
+
+	private FileChannelDataBlockManagedFileChannel() {
+	}
+
+	public static int BUFFER_SIZE = FileChannelDataBlock.ManagedFileChannel.BUFFER_SIZE;
+
+}