Memory Management: Dispose IDisposable resources correctly in four internal classes

src/Umbraco.Cms.DevelopmentMode.Backoffice/InMemoryAuto/InMemoryAssemblyLoadContextManager.cs

@@ -3,13 +3,16 @@
 
 namespace Umbraco.Cms.DevelopmentMode.Backoffice.InMemoryAuto;
 
-internal sealed class InMemoryAssemblyLoadContextManager
+internal sealed class InMemoryAssemblyLoadContextManager : IDisposable
 {
     private UmbracoAssemblyLoadContext? _currentAssemblyLoadContext;
 
     public InMemoryAssemblyLoadContextManager() =>
         AssemblyLoadContext.Default.Resolving += OnResolvingDefaultAssemblyLoadContext;
 
+    public void Dispose() =>
+        AssemblyLoadContext.Default.Resolving -= OnResolvingDefaultAssemblyLoadContext;
+
     private string? _modelsAssemblyLocation;
 
     public string? ModelsAssemblyLocation => _modelsAssemblyLocation;

src/Umbraco.Infrastructure/Security/MemberPasswordHasher.cs

@@ -161,8 +161,8 @@ private bool IsSuccessfulLegacyPassword(string hashedPassword, string providedPa
     private static string DecryptLegacyPassword(string encryptedPassword, SymmetricAlgorithm algorithm)
     {
         using var memoryStream = new MemoryStream();
-        ICryptoTransform cryptoTransform = algorithm.CreateDecryptor();
-        var cryptoStream = new CryptoStream(memoryStream, cryptoTransform, CryptoStreamMode.Write);
+        using ICryptoTransform cryptoTransform = algorithm.CreateDecryptor();
+        using var cryptoStream = new CryptoStream(memoryStream, cryptoTransform, CryptoStreamMode.Write);
         var buf = Convert.FromBase64String(encryptedPassword);
         cryptoStream.Write(buf, 0, 32);
         cryptoStream.FlushFinalBlock();

src/Umbraco.Infrastructure/Services/CacheInstructionService.cs

@@ -290,7 +290,17 @@ private int ProcessDatabaseInstructions(CacheRefresherCollection cacheRefreshers
                         continue;
                     }
 
-                    List<RefreshInstruction> instructionBatch = GetAllInstructions(jsonInstructions?.RootElement);
+                    // Dispose the JsonDocument once we've extracted instructions from its RootElement.
+                    // Use try/finally to ensure pooled buffers are returned even if retrieving the instructions throws.
+                    List<RefreshInstruction> instructionBatch;
+                    try
+                    {
+                        instructionBatch = GetAllInstructions(jsonInstructions?.RootElement);
+                    }
+                    finally
+                    {
+                        jsonInstructions?.Dispose();
+                    }
 
                     // Process as per-normal.
                     var success = ProcessDatabaseInstructions(cacheRefreshers, instructionBatch, instruction, processed, cancellationToken, ref lastId);

src/Umbraco.Infrastructure/Sync/DatabaseServerMessenger.cs

@@ -343,6 +343,7 @@ protected virtual void Dispose(bool disposing)
             if (disposing)
             {
                 _syncIdle.Dispose();
+                _cancellationTokenSource.Dispose();
             }
 
             _disposedValue = true;