Add missing clearing of pooled arrays

src/Components/Components/src/NavigationManager.cs

@@ -447,6 +447,7 @@ protected async ValueTask<bool> NotifyLocationChangingAsync(string uri, string?
                 }
                 finally
                 {
+                    locationChangingHandlersCopy.AsSpan(0, handlerCount).Clear();
                     ArrayPool<Func<LocationChangingContext, ValueTask>>.Shared.Return(locationChangingHandlersCopy);
                 }
             }

src/Components/Endpoints/src/FormMapping/Converters/CollectionAdapters/ArrayPoolBufferAdapter.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Buffers;
+using System.Runtime.CompilerServices;
 
 namespace Microsoft.AspNetCore.Components.Endpoints.FormMapping;
 
@@ -17,7 +18,14 @@ public static PooledBuffer Add(ref PooledBuffer buffer, TElement element)
         {
             var newBuffer = ArrayPool<TElement>.Shared.Rent(buffer.Data.Length * 2);
             Array.Copy(buffer.Data, newBuffer, buffer.Data.Length);
+
+            if (RuntimeHelpers.IsReferenceOrContainsReferences<TElement>())
+            {
+                buffer.Data.AsSpan(0, buffer.Count).Clear();
+            }
+
             ArrayPool<TElement>.Shared.Return(buffer.Data);
+
             buffer.Data = newBuffer;
         }
 
@@ -28,7 +36,14 @@ public static PooledBuffer Add(ref PooledBuffer buffer, TElement element)
     public static TCollection ToResult(PooledBuffer buffer)
     {
         var result = TCollectionFactory.ToResultCore(buffer.Data, buffer.Count);
+
+        if (RuntimeHelpers.IsReferenceOrContainsReferences<TElement>())
+        {
+            buffer.Data.AsSpan(0, buffer.Count).Clear();
+        }
+
         ArrayPool<TElement>.Shared.Return(buffer.Data);
+
         return result;
     }
 

src/Components/Endpoints/src/FormMapping/PrefixResolver.cs

@@ -38,6 +38,7 @@ public void Dispose()
     {
         if (_sortedKeys != null)
         {
+            _sortedKeys.AsSpan(0, _length).Clear();
             ArrayPool<FormKey>.Shared.Return(_sortedKeys);
         }
     }

src/Middleware/OutputCaching/src/OutputCacheEntryFormatter.cs

@@ -49,6 +49,11 @@ public static async ValueTask StoreAsync(string key, OutputCacheEntry value, Has
                 await bufferStore.SetAsync(key, new(buffer.GetCommittedMemory()), CopyToLeasedMemory(tags, out var lease), duration, cancellationToken);
                 if (lease is not null)
                 {
+                    if (tags is not null)
+                    {
+                        lease.AsSpan(0, tags.Count).Clear();
+                    }
+
                     ArrayPool<string>.Shared.Return(lease);
                 }
             }

src/Middleware/OutputCaching/src/RecyclableArrayBufferWriter.cs

@@ -3,6 +3,7 @@
 
 using System.Buffers;
 using System.Diagnostics;
+using System.Runtime.CompilerServices;
 
 namespace Microsoft.AspNetCore.OutputCaching;
 
@@ -32,10 +33,16 @@ public RecyclableArrayBufferWriter()
     public void Dispose()
     {
         var tmp = _buffer;
+        var count = _index;
         _index = 0;
         _buffer = Array.Empty<T>();
         if (tmp.Length != 0)
         {
+            if (RuntimeHelpers.IsReferenceOrContainsReferences<T>())
+            {
+                tmp.AsSpan(0, count).Clear();
+            }
+
             ArrayPool<T>.Shared.Return(tmp);
         }
     }
@@ -120,6 +127,11 @@ private void CheckAndResizeBuffer(int sizeHint)
             oldArray.AsSpan(0, _index).CopyTo(_buffer);
             if (oldArray.Length != 0)
             {
+                if (RuntimeHelpers.IsReferenceOrContainsReferences<T>())
+                {
+                    oldArray.AsSpan(0, _index).Clear();
+                }
+
                 ArrayPool<T>.Shared.Return(oldArray);
             }
         }

src/Mvc/Mvc.NewtonsoftJson/src/JsonArrayPool.cs

@@ -3,6 +3,7 @@
 
 using System.Buffers;
 using Newtonsoft.Json;
+using System.Runtime.CompilerServices;
 
 namespace Microsoft.AspNetCore.Mvc.NewtonsoftJson;
 
@@ -26,6 +27,11 @@ public void Return(T[]? array)
     {
         ArgumentNullException.ThrowIfNull(array);
 
+        if (RuntimeHelpers.IsReferenceOrContainsReferences<T>())
+        {
+            array.AsSpan().Clear();
+        }
+
         _inner.Return(array);
     }
 }

src/Shared/ValueStringBuilder/ValueListBuilder.cs

@@ -60,6 +60,12 @@ public void Dispose()
         if (toReturn != null)
         {
             _arrayFromPool = null;
+
+            if (RuntimeHelpers.IsReferenceOrContainsReferences<T>())
+            {
+                toReturn.AsSpan(0, _pos).Clear();
+            }
+
             ArrayPool<T>.Shared.Return(toReturn);
         }
     }
@@ -95,6 +101,11 @@ private void Grow(int additionalCapacityRequired = 1)
         _span = _arrayFromPool = array;
         if (toReturn != null)
         {
+            if (RuntimeHelpers.IsReferenceOrContainsReferences<T>())
+            {
+                toReturn.AsSpan(0, _pos).Clear();
+            }
+
             ArrayPool<T>.Shared.Return(toReturn);
         }
     }

src/SignalR/common/Shared/JsonUtils.cs

@@ -5,6 +5,7 @@
 using System.Buffers;
 using System.Globalization;
 using System.IO;
+using System.Runtime.CompilerServices;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 
@@ -216,6 +217,15 @@ public void Return(T[]? array)
                 return;
             }
 
+#if NET
+            if (RuntimeHelpers.IsReferenceOrContainsReferences<T>())
+#else
+            if (!typeof(T).IsPrimitive)
+#endif
+            {
+                array.AsSpan().Clear();
+            }
+
             _inner.Return(array);
         }
     }