From 467850f7570fd79f3c2e144fceb57c5542cd2307 Mon Sep 17 00:00:00 2001
From: Anton Firszov <antonfir@gmail.com>
Date: Wed, 8 May 2024 18:01:38 +0200
Subject: [PATCH] Fix overflow in MemoryAllocator.Create(options) (#2730)

Fix an overlook from #2706. See https://github.com/SixLabors/ImageSharp/commit/92b82779ac8e7a032989533bb9a01ef092186b2e#r141770676.
---
 .../Memory/Allocators/MemoryAllocator.cs         |  2 +-
 .../UniformUnmanagedPoolMemoryAllocatorTests.cs  | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/ImageSharp/Memory/Allocators/MemoryAllocator.cs b/src/ImageSharp/Memory/Allocators/MemoryAllocator.cs
index b56bedd045..8eaf0b6d69 100644
--- a/src/ImageSharp/Memory/Allocators/MemoryAllocator.cs
+++ b/src/ImageSharp/Memory/Allocators/MemoryAllocator.cs
@@ -49,7 +49,7 @@ public static MemoryAllocator Create(MemoryAllocatorOptions options)
         UniformUnmanagedMemoryPoolMemoryAllocator allocator = new(options.MaximumPoolSizeMegabytes);
         if (options.AllocationLimitMegabytes.HasValue)
         {
-            allocator.MemoryGroupAllocationLimitBytes = options.AllocationLimitMegabytes.Value * 1024 * 1024;
+            allocator.MemoryGroupAllocationLimitBytes = options.AllocationLimitMegabytes.Value * 1024L * 1024L;
             allocator.SingleBufferAllocationLimitBytes = (int)Math.Min(allocator.SingleBufferAllocationLimitBytes, allocator.MemoryGroupAllocationLimitBytes);
         }
 
diff --git a/tests/ImageSharp.Tests/Memory/Allocators/UniformUnmanagedPoolMemoryAllocatorTests.cs b/tests/ImageSharp.Tests/Memory/Allocators/UniformUnmanagedPoolMemoryAllocatorTests.cs
index 077d0afed8..aa34a5c108 100644
--- a/tests/ImageSharp.Tests/Memory/Allocators/UniformUnmanagedPoolMemoryAllocatorTests.cs
+++ b/tests/ImageSharp.Tests/Memory/Allocators/UniformUnmanagedPoolMemoryAllocatorTests.cs
@@ -442,4 +442,20 @@ public void AllocateGroup_OverLimit_ThrowsInvalidMemoryOperationException()
         allocator.AllocateGroup<byte>(4 * oneMb, 1024).Dispose(); // Should work
         Assert.Throws<InvalidMemoryOperationException>(() => allocator.AllocateGroup<byte>(5 * oneMb, 1024));
     }
+
+    [ConditionalFact(typeof(Environment), nameof(Environment.Is64BitProcess))]
+    public void MemoryAllocator_Create_SetHighLimit()
+    {
+        RemoteExecutor.Invoke(RunTest).Dispose();
+        static void RunTest()
+        {
+            const long threeGB = 3L * (1 << 30);
+            MemoryAllocator allocator = MemoryAllocator.Create(new MemoryAllocatorOptions()
+            {
+                AllocationLimitMegabytes = (int)(threeGB / 1024)
+            });
+            using MemoryGroup<byte> memoryGroup = allocator.AllocateGroup<byte>(threeGB, 1024);
+            Assert.Equal(threeGB, memoryGroup.TotalLength);
+        }
+    }
 }