Fix #3009

Author: JimBobSquarePants

src/ImageSharp/Image.FromBytes.cs

@@ -34,7 +34,12 @@ public static IImageFormat DetectFormat(ReadOnlySpan<byte> buffer)
     /// <exception cref="UnknownImageFormatException">The encoded image format is unknown.</exception>
     public static unsafe IImageFormat DetectFormat(DecoderOptions options, ReadOnlySpan<byte> buffer)
     {
-        Guard.NotNull(options, nameof(options.Configuration));
+        Guard.NotNull(options, nameof(options));
+
+        if (buffer.IsEmpty)
+        {
+            throw new UnknownImageFormatException("Cannot detect image format from empty data.");
+        }
 
         fixed (byte* ptr = buffer)
         {
@@ -66,6 +71,13 @@ public static ImageInfo Identify(ReadOnlySpan<byte> buffer)
     /// <exception cref="UnknownImageFormatException">The encoded image format is unknown.</exception>
     public static unsafe ImageInfo Identify(DecoderOptions options, ReadOnlySpan<byte> buffer)
     {
+        Guard.NotNull(options, nameof(options));
+
+        if (buffer.IsEmpty)
+        {
+            throw new UnknownImageFormatException("Cannot identify image format from empty data.");
+        }
+
         fixed (byte* ptr = buffer)
         {
             using UnmanagedMemoryStream stream = new(ptr, buffer.Length);
@@ -99,6 +111,13 @@ public static Image Load(ReadOnlySpan<byte> buffer)
     /// <exception cref="UnknownImageFormatException">The encoded image format is unknown.</exception>
     public static unsafe Image Load(DecoderOptions options, ReadOnlySpan<byte> buffer)
     {
+        Guard.NotNull(options, nameof(options));
+
+        if (buffer.IsEmpty)
+        {
+            throw new UnknownImageFormatException("Cannot load image from empty data.");
+        }
+
         fixed (byte* ptr = buffer)
         {
             using UnmanagedMemoryStream stream = new(ptr, buffer.Length);
@@ -133,6 +152,13 @@ public static Image<TPixel> Load<TPixel>(ReadOnlySpan<byte> data)
     public static unsafe Image<TPixel> Load<TPixel>(DecoderOptions options, ReadOnlySpan<byte> data)
         where TPixel : unmanaged, IPixel<TPixel>
     {
+        Guard.NotNull(options, nameof(options));
+
+        if (data.IsEmpty)
+        {
+            throw new UnknownImageFormatException("Cannot load image from empty data.");
+        }
+
         fixed (byte* ptr = data)
         {
             using UnmanagedMemoryStream stream = new(ptr, data.Length);

src/ImageSharp/Image.LoadPixelData.cs

@@ -69,6 +69,11 @@ public static Image<TPixel> LoadPixelData<TPixel>(Configuration configuration, R
     {
         Guard.NotNull(configuration, nameof(configuration));
 
+        if (data.IsEmpty)
+        {
+            throw new ArgumentException("Pixel data cannot be empty.", nameof(data));
+        }
+
         int count = width * height;
         Guard.MustBeGreaterThanOrEqualTo(data.Length, count, nameof(data));
 

tests/ImageSharp.Tests/Image/ImageTests.DetectFormat.cs

@@ -50,6 +50,10 @@ public void FromBytes_CustomConfiguration()
             Assert.Equal(this.LocalImageFormat, format);
         }
 
+        [Fact]
+        public void FromBytes_EmptySpan_Throws()
+            => Assert.Throws<UnknownImageFormatException>(() => Image.DetectFormat([]));
+
         [Fact]
         public void FromFileSystemPath_GlobalConfiguration()
         {

tests/ImageSharp.Tests/Image/ImageTests.Identify.cs

@@ -38,6 +38,10 @@ public void FromBytes_GlobalConfiguration()
             Assert.Equal(ExpectedGlobalFormat, info.Metadata.DecodedImageFormat);
         }
 
+        [Fact]
+        public void FromBytes_EmptySpan_Throws()
+            => Assert.Throws<UnknownImageFormatException>(() => Image.Identify([]));
+
         [Fact]
         public void FromBytes_CustomConfiguration()
         {

tests/ImageSharp.Tests/Image/ImageTests.Load_FromBytes_PassLocalConfiguration.cs

@@ -79,5 +79,16 @@ public void Configuration_Bytes_OutFormat_Agnostic()
 
             this.TestFormat.VerifyAgnosticDecodeCall(this.Marker, this.TopLevelConfiguration);
         }
+
+        [Fact]
+        public void FromBytes_EmptySpan_Throws()
+        {
+            DecoderOptions options = new()
+            {
+                Configuration = this.TopLevelConfiguration
+            };
+
+            Assert.Throws<UnknownImageFormatException>(() => Image.Load(options, []));
+        }
     }
 }

tests/ImageSharp.Tests/Image/ImageTests.Load_FromBytes_UseGlobalConfiguration.cs

@@ -45,5 +45,9 @@ public void Bytes_OutFormat_Agnostic()
             VerifyDecodedImage(img);
             Assert.IsType<BmpFormat>(img.Metadata.DecodedImageFormat);
         }
+
+        [Fact]
+        public void FromBytes_EmptySpan_Throws()
+            => Assert.ThrowsAny<UnknownImageFormatException>(() => Image.Load<Rgba32>([]));
     }
 }

tests/ImageSharp.Tests/Image/ImageTests.Load_FromStream_ThrowsRightException.cs

@@ -32,6 +32,17 @@ public void Image_Load_T_Throws_UnknownImageFormatException()
                 }
             });
 
-        public void Dispose() => this.Stream?.Dispose();
+        [Fact]
+        public void FromStream_Empty_Throws()
+        {
+            using MemoryStream ms = new();
+            Assert.Throws<UnknownImageFormatException>(() => Image.Load(DecoderOptions.Default, ms));
+        }
+
+        public void Dispose()
+        {
+            this.Stream?.Dispose();
+            GC.SuppressFinalize(this);
+        }
     }
 }