Fix segmentation fault when calling Zstd.loadFastDictDecompress(long, ZstdDictDecompress)

garydgregory · luben · commit b97eed71fd7c · 2025-04-28T14:31:24.000Z
diff --git a/src/main/native/jni_zstd.c b/src/main/native/jni_zstd.c
@@ -254,6 +254,7 @@ JNIEXPORT jint JNICALL Java_com_github_luben_zstd_Zstd_loadDictDecompress
  */
 JNIEXPORT jint JNICALL Java_com_github_luben_zstd_Zstd_loadFastDictDecompress
   (JNIEnv *env, jclass obj, jlong stream, jobject dict) {
+    if (dict == NULL) return -ZSTD_error_dictionary_wrong;
     jclass dict_clazz = (*env)->GetObjectClass(env, dict);
     jfieldID decompress_dict = (*env)->GetFieldID(env, dict_clazz, "nativePtr", "J");
     ZSTD_DDict* ddict = (ZSTD_DDict*)(intptr_t)(*env)->GetLongField(env, dict, decompress_dict);
diff --git a/src/test/scala/Zstd.scala b/src/test/scala/Zstd.scala
@@ -918,14 +918,25 @@ class ZstdSpec extends AnyFlatSpec with ScalaCheckPropertyChecks {
     }
   }
 
-  "ZstdOutputStream" should s"do not cause a segmentation fault" in {
+  "ZstdOutputStream" should s"do not cause a segmentation fault in setDict(ZstdDictCompress)" in {
     val os  = new ByteArrayOutputStream(100)
     val zos = new ZstdOutputStream(os)
     assertThrows[ZstdIOException] {
       zos.setDict(null.asInstanceOf[ZstdDictCompress])
     }
   }
 
+  "Zstd" should s"do not cause a segmentation fault in loadFastDictDecompress()" in {
+    val zin = new ZstdInputStreamNoFinalizer(new ByteArrayInputStream(Array[Byte]()))
+    assertThrows[NullPointerException] {
+      zin.setDict(null.asInstanceOf[ZstdDictDecompress])
+    }
+    // Avoid:
+    //  0 0x0000000103a067c8 AccessInternal::PostRuntimeDispatch<G1BarrierSet::AccessBarrier<548964ull, G1BarrierSet>, (AccessInternal::BarrierType)2, 548964ull>::oop_access_barrier(void*) + 8 in libjvm.dylib
+    //  1 0x0000000103daa0f8 jni_GetObjectClass + 184 in libjvm.dylib
+    assert(Zstd.loadFastDictDecompress(0, null.asInstanceOf[ZstdDictDecompress]) == -32)
+  }
+
   "ZstdDirectBufferCompressingStream" should s"do nothing on double close but throw on writing on closed stream" in {
     val os  = ByteBuffer.allocateDirect(100)
     val zos = new ZstdDirectBufferCompressingStream(os, 1)
