From 02d8f53246b326ccf5904a6314f9e9f0293e2a47 Mon Sep 17 00:00:00 2001
From: Florian Schmaus <flo@geekplace.eu>
Date: Tue, 15 Oct 2024 12:47:55 +0200
Subject: [PATCH] [core] Increase resilience against faulty parser
 implementions

If one of the parser throws a NullPointerException or
NumberFormatException, then this should not lead to a disconnect due
to an unhandled exception. Instead wrap those in an exception that is
handled by the parsing exception callback and ask the user to fill a
bug report for those faulty parsers.

We may adjust the list of exceptions that are wrapped in the future.
---
 .../jivesoftware/smack/AbstractXMPPConnection.java |  9 ++++++++-
 .../main/java/org/jivesoftware/smack/Smack.java    | 14 +++++++++++++-
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java b/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java
index a3fc2f941..00d19c4f0 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java
@@ -1460,7 +1460,14 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
         int parserDepth = parser.getDepth();
         Stanza stanza = null;
         try {
-            stanza = PacketParserUtils.parseStanza(parser, incomingStreamXmlEnvironment);
+            try {
+                stanza = PacketParserUtils.parseStanza(parser, incomingStreamXmlEnvironment);
+            } catch (NullPointerException | NumberFormatException e) {
+                // Those exceptions should probably be wrapped into a SmackParsingException and therefore likely constitute a missing verification in the throwing parser.
+                String message = "Smack parser throw unexpected exception '" + e.getMessage() + "', please report this at " + Smack.BUG_REPORT_URL;
+                LOGGER.log(Level.SEVERE, message, e);
+                throw new IOException(message, e);
+            }
         }
         catch (XmlPullParserException | SmackParsingException | IOException | IllegalArgumentException e) {
             CharSequence content = PacketParserUtils.parseContentDepth(parser,
diff --git a/smack-core/src/main/java/org/jivesoftware/smack/Smack.java b/smack-core/src/main/java/org/jivesoftware/smack/Smack.java
index daa7a18b4..6996e1ac9 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/Smack.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/Smack.java
@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2020-2021 Florian Schmaus
+ * Copyright 2020-2024 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,8 @@
 package org.jivesoftware.smack;
 
 import java.io.InputStream;
+import java.net.MalformedURLException;
+import java.net.URL;
 import java.util.logging.Logger;
 
 import org.jivesoftware.smack.util.FileUtils;
@@ -29,6 +31,16 @@ public class Smack {
 
     public static final String SMACK_PACKAGE = SMACK_ORG + ".smack";
 
+    public static final URL BUG_REPORT_URL;
+
+    static {
+        try {
+            BUG_REPORT_URL = new URL("https://discourse.igniterealtime.org/c/smack/smack-support/9");
+        } catch (MalformedURLException e) {
+            throw new ExceptionInInitializerError(e);
+        }
+    }
+
     /**
      * Returns the Smack version information, e.g."1.3.0".
      *