From f36ec126959b2a7fe021aa51678c64e658e9fb2e Mon Sep 17 00:00:00 2001
From: antonfirsov <antonfir@gmail.com>
Date: Sun, 15 Oct 2023 14:47:56 +0200
Subject: [PATCH] Disallow allocation attempts of unrepresentable sizes

backport of #2545
---
 .../UniformUnmanagedMemoryPoolMemoryAllocator.cs           | 5 +++++
 tests/ImageSharp.Tests/Image/ImageTests.cs                 | 4 ++++
 .../Allocators/UniformUnmanagedPoolMemoryAllocatorTests.cs | 7 +++++++
 3 files changed, 16 insertions(+)

diff --git a/src/ImageSharp/Memory/Allocators/UniformUnmanagedMemoryPoolMemoryAllocator.cs b/src/ImageSharp/Memory/Allocators/UniformUnmanagedMemoryPoolMemoryAllocator.cs
index 0da4ff9f8c..7395ec9ac7 100644
--- a/src/ImageSharp/Memory/Allocators/UniformUnmanagedMemoryPoolMemoryAllocator.cs
+++ b/src/ImageSharp/Memory/Allocators/UniformUnmanagedMemoryPoolMemoryAllocator.cs
@@ -121,6 +121,11 @@ internal override MemoryGroup<T> AllocateGroup<T>(
             AllocationOptions options = AllocationOptions.None)
         {
             long totalLengthInBytes = totalLength * Unsafe.SizeOf<T>();
+            if (totalLengthInBytes < 0)
+            {
+                throw new InvalidMemoryOperationException("Attempted to allocate a MemoryGroup of a size that is not representable.");
+            }
+
             if (totalLengthInBytes <= this.sharedArrayPoolThresholdInBytes)
             {
                 var buffer = new SharedArrayPoolBuffer<T>((int)totalLength);
diff --git a/tests/ImageSharp.Tests/Image/ImageTests.cs b/tests/ImageSharp.Tests/Image/ImageTests.cs
index 0a9e2817a5..1bfd307cbd 100644
--- a/tests/ImageSharp.Tests/Image/ImageTests.cs
+++ b/tests/ImageSharp.Tests/Image/ImageTests.cs
@@ -40,6 +40,10 @@ public void Width_Height()
                 }
             }
 
+            [Fact]
+            public void Width_Height_SizeNotRepresentable_ThrowsInvalidImageOperationException()
+                => Assert.Throws<InvalidMemoryOperationException>(() => new Image<Rgba32>(int.MaxValue, int.MaxValue));
+
             [Fact]
             public void Configuration_Width_Height()
             {
diff --git a/tests/ImageSharp.Tests/Memory/Allocators/UniformUnmanagedPoolMemoryAllocatorTests.cs b/tests/ImageSharp.Tests/Memory/Allocators/UniformUnmanagedPoolMemoryAllocatorTests.cs
index 0520c3c1fe..f49dcf05db 100644
--- a/tests/ImageSharp.Tests/Memory/Allocators/UniformUnmanagedPoolMemoryAllocatorTests.cs
+++ b/tests/ImageSharp.Tests/Memory/Allocators/UniformUnmanagedPoolMemoryAllocatorTests.cs
@@ -111,6 +111,13 @@ public void AllocateGroup_MultipleTimes_ExceedPoolLimit()
             }
         }
 
+        [Fact]
+        public void AllocateGroup_SizeInBytesOverLongMaxValue_ThrowsInvalidMemoryOperationException()
+        {
+            var allocator = new UniformUnmanagedMemoryPoolMemoryAllocator(null);
+            Assert.Throws<InvalidMemoryOperationException>(() => allocator.AllocateGroup<S4>(int.MaxValue * (long)int.MaxValue, int.MaxValue));
+        }
+
         [Fact]
         public unsafe void Allocate_MemoryIsPinnableMultipleTimes()
         {