Fixes for #424: Add null checking and wrap NPE

ion/src/main/java/com/fasterxml/jackson/dataformat/ion/IonParser.java

@@ -278,9 +278,10 @@ public String getText() throws IOException
                     // trying to get the text for a symbol id that cannot be resolved.
                     // stringValue() has an assert statement which could throw an
                     throw _constructError(e.getMessage(), e);
-                } catch (AssertionError e) {
+                } catch (AssertionError | NullPointerException e) {
                     // AssertionError if we're trying to get the text with a symbol
                     // id less than or equals to 0.
+                    // NullPointerException may also be thrown on invalid data
                     String msg = e.getMessage();
                     if (msg == null) {
                         msg = "UNKNOWN ROOT CAUSE";
@@ -331,34 +332,50 @@ public int getTextOffset() throws IOException {
 
     @Override
     public BigInteger getBigIntegerValue() throws IOException {
+        _verifyIsNumberToken();
         return _reader.bigIntegerValue();
     }
 
     @Override
     public BigDecimal getDecimalValue() throws IOException {
+        _verifyIsNumberToken();
         return _reader.bigDecimalValue();
     }
 
     @Override
     public double getDoubleValue() throws IOException {
+        _verifyIsNumberToken();
         return _reader.doubleValue();
     }
 
     @Override
     public float getFloatValue() throws IOException {
+        _verifyIsNumberToken();
         return (float) _reader.doubleValue();
     }
 
     @Override
     public int getIntValue() throws IOException {
+        _verifyIsNumberToken();
         return _reader.intValue();
     }
 
     @Override
     public long getLongValue() throws IOException {
+        _verifyIsNumberToken();
         return _reader.longValue();
     }
 
+    // @since 2.17
+    private void _verifyIsNumberToken() throws IOException
+    {
+        if (_currToken != JsonToken.VALUE_NUMBER_INT && _currToken != JsonToken.VALUE_NUMBER_FLOAT) {
+            // Same as `ParserBase._parseNumericValue()` exception:
+            _reportError("Current token (%s) not numeric, can not use numeric value accessors",
+                    _currToken);
+        }
+    }
+
     @Override
     public NumberType getNumberType() throws IOException
     {

ion/src/test/java/com/fasterxml/jackson/dataformat/ion/fuzz/Fuzz424_65065_65126NPETest.java

@@ -0,0 +1,48 @@
+package com.fasterxml.jackson.dataformat.ion.fuzz;
+
+import java.io.ByteArrayInputStream;
+
+import org.hamcrest.Matchers;
+import org.junit.Test;
+
+import com.fasterxml.jackson.core.exc.StreamReadException;
+import com.fasterxml.jackson.dataformat.ion.*;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.fail;
+
+// [dataformats-binary#424]
+public class Fuzz424_65065_65126NPETest
+{
+    @Test
+    public void testFuzz65065() throws Exception {
+       IonFactory f = IonFactory
+                          .builderForBinaryWriters()
+                          .build();
+
+       IonObjectMapper mapper = IonObjectMapper.builder(f).build();
+
+       try {
+           byte[] bytes = {(byte) -32, (byte) 1, (byte) 0, (byte) -22, (byte) 123, (byte) -112};
+           mapper.readTree(f.createParser(new ByteArrayInputStream(bytes)));
+           fail("Should not pass (invalid content)");
+       } catch (StreamReadException e) {
+           assertThat(e.getMessage(), Matchers.containsString("Internal `IonReader` error"));
+       }
+    }
+
+    @Test
+    public void testFuzz65126() throws Exception {
+       IonFactory f = IonFactory
+                          .builderForBinaryWriters()
+                          .build();
+
+       try {
+           byte[] bytes = {(byte) 1, (byte) 0};
+           f.createParser(bytes).getDecimalValue();
+           fail("Should not pass (invalid content)");
+       } catch (StreamReadException e) {
+           assertThat(e.getMessage(), Matchers.containsString("Current token (null) not numeric"));
+       }
+    }
+}

release-notes/CREDITS-2.x

@@ -287,3 +287,6 @@ Arthur Chan (@arthurscchan)
  (2.17.0)
  * Contributed #420: (ion) `IndexOutOfBoundsException` thrown by `IonReader` implementations
  (2.17.0)
+ * Contributed #424: (ion) `IonReader` throws `NullPointerException` for unchecked
+   invalid data
+ (2.17.0)

release-notes/VERSION-2.x

@@ -22,6 +22,8 @@ Active maintainers:
 #420: (ion) `IndexOutOfBoundsException` thrown by `IonReader` implementations
   are not handled 
  (contributed by Arthur C)
+#424: (ion) `IonReader` throws `NullPointerException` for unchecked invalid data
+ (contributed by Arthur C)
 -(ion) Update `com.amazon.ion:ion-java` to 1.11.0 (from 1.10.5)
 
 2.16.0 (15-Nov-2023)