Example reproducing the issue described in https://bugs.openjdk.org/browse/JDK-8280703

DecryptAlloc.java

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.nio.ByteBuffer;
import java.security.GeneralSecurityException;

/**
 * This demonstrates a memory allocation problem in com.sun.crypto.provider.CipherCore.
 * <p>
 * To reproduce the issue, run this class using:
 * <code>-XX:+FlightRecorder -XX:StartFlightRecording=dumponexit=true,filename=decryptAlloc.jfr</code>
 */
public class DecryptAlloc {

	public static void main(String[] args) throws GeneralSecurityException {
		var cipher = Cipher.getInstance("AES/CTR/NoPadding");
		var key = new SecretKeySpec(new byte[32], "AES");
		var iv = new IvParameterSpec(new byte[16]);

		// encryption runs fine:
		cipher.init(Cipher.ENCRYPT_MODE, key, iv);
		ByteBuffer cleartext = ByteBuffer.allocate(4096);
		ByteBuffer ciphertext = ByteBuffer.allocate(cipher.getOutputSize(4096));
		for (int i = 0; i < 1_000_000; i++) {
			cleartext.clear();
			ciphertext.clear();
			cipher.doFinal(cleartext, ciphertext);
		}

		// decryption causes lots of allocations:
		cipher.init(Cipher.DECRYPT_MODE, key, iv);
		for (int i = 0; i < 1_000_000; i++) {
			cleartext.clear();
			ciphertext.clear();
			cipher.doFinal(ciphertext, cleartext);
		}
		
		// "Blackhole.consume()" for dummies:
		System.out.println(cleartext);
	}

}