dnlib x64 exhausts all memory when read method body.

test.zip

static void Main(string[] args) {
        Console.WriteLine(IntPtr.Size); // Can only reproduce if current program is AnyCPU/x64
	var module = ModuleDefMD.Load("test.exe");
	var method = module.ResolveMethod(0x11d);
	var body = method.Body; // here
        Console.WriteLine(body);
	Console.ReadKey();
}

[CreateAndInject]

But the first parameter of GenericParamUser is ushort number rather than uint number

Yes but it doesn’t mean the runtime will throw or report an error if the signature has > 0x10000 generic arguments. Have you tested this? If the runtime doesn’t do anything and the code just runs, we need to support it too.

Yes, I test it, when run the output Test.exe .NET will throw TypeLoadException when greater than 65535: Internal limit: There’re so many generic arguments. (I don’t know the exact message, I translate from Chinese) EDIT: TypeLoadException even if 0-65535 without overflow

var module = new ModuleDefUser("Test.exe");
new AssemblyDefUser("Test").Modules.Add(module);
module.Kind = ModuleKind.Console;
var type = new TypeDefUser("Program", module.CorLibTypes.Object.TypeDefOrRef);
var method = new MethodDefUser("Main", MethodSig.CreateStatic(module.CorLibTypes.Void), MethodAttributes.Public | MethodAttributes.Static);
module.EntryPoint = method;
method.Body = new CilBody();
var instrs = method.Body.Instructions;
var generic = new TypeDefUser("Generic", module.CorLibTypes.Object.TypeDefOrRef);
int max = 65536;
for (int i = 0; i < max; i++) {
	ushort number = (ushort)i;
	generic.GenericParameters.Add(new GenericParamUser(number, GenericParamAttributes.NonVariant, "T" + i));
}
module.Types.Add(generic);
instrs.Add(OpCodes.Ldtoken.ToInstruction(generic));
instrs.Add(OpCodes.Call.ToInstruction(new MemberRefUser(module, "GetTypeFromHandle", MethodSig.CreateStatic(new ClassSig(module.CorLibTypes.GetTypeRef("System", "Type")), new ValueTypeSig(module.CorLibTypes.GetTypeRef("System", "RuntimeTypeHandle"))), module.CorLibTypes.GetTypeRef("System", "Type"))));
instrs.Add(OpCodes.Call.ToInstruction(new MemberRefUser(module, "WriteLine", MethodSig.CreateStatic(module.CorLibTypes.Void, module.CorLibTypes.Object), module.CorLibTypes.GetTypeRef("System", "Console"))));
instrs.Add(OpCodes.Call.ToInstruction(new MemberRefUser(module, "ReadLine", MethodSig.CreateStatic(module.CorLibTypes.String), module.CorLibTypes.GetTypeRef("System", "Console"))));
instrs.Add(OpCodes.Ret.ToInstruction());
method.DeclaringType = type;
module.Types.Add(type);
module.Write("Test.exe");
Console.WriteLine("OK");
Console.ReadKey();

[wwh1004]

>	dnlib.dll!dnlib.DotNet.SignatureReader.ReadSig<dnlib.DotNet.MethodSig>(dnlib.DotNet.MethodSig methodSig) Line 493	C#
 	dnlib.dll!dnlib.DotNet.SignatureReader.ReadMethod(dnlib.DotNet.CallingConvention callingConvention) Line 474	C#
 	dnlib.dll!dnlib.DotNet.SignatureReader.ReadSig() Line 434	C#
 	dnlib.dll!dnlib.DotNet.SignatureReader.ReadSig(dnlib.DotNet.ModuleDefMD readerModule, uint sig, dnlib.DotNet.GenericParamContext gpContext) Line 70	C#
 	dnlib.dll!dnlib.DotNet.ModuleDefMD.ReadSignature(uint sig, dnlib.DotNet.GenericParamContext gpContext) Line 1219	C#
 	dnlib.dll!dnlib.DotNet.StandAloneSigMD.StandAloneSigMD(dnlib.DotNet.ModuleDefMD readerModule, uint rid, dnlib.DotNet.GenericParamContext gpContext) Line 174	C#

its metadata is invalid. bp at line ‘if (!reader.TryReadCompressedUInt32(out uint numParams))’ you will see ‘numParams’ is a extremely large number.