From e5f0c361f5baea5e2b56e1776143d841b0cc6e6c Mon Sep 17 00:00:00 2001
From: Fan Yang <52458914+fanyang-mono@users.noreply.github.com>
Date: Tue, 19 Mar 2024 12:20:23 -0400
Subject: [PATCH] Add generic parameter checks for fields of generic types
 (#99911)

---
 src/mono/mono/metadata/class-init.c                           | 4 ++++
 .../Loader/classloader/generics/ByRefLike/ValidateNegative.cs | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/mono/mono/metadata/class-init.c b/src/mono/mono/metadata/class-init.c
index 6d2426cc71a49..d9cfd751c8192 100644
--- a/src/mono/mono/metadata/class-init.c
+++ b/src/mono/mono/metadata/class-init.c
@@ -2573,6 +2573,10 @@ mono_class_layout_fields (MonoClass *klass, int base_instance_size, int packing_
 		case MONO_TYPE_VALUETYPE:
 		case MONO_TYPE_GENERICINST:
 			field_class = mono_class_from_mono_type_internal (field->type);
+			if (mono_class_is_ginst (field_class) && !mono_verifier_class_is_valid_generic_instantiation (field_class)) {
+				mono_class_set_type_load_failure (klass, "Field '%s' is an invalid generic instantiation of type %s", field->name, mono_type_get_full_name (field_class));
+				return;
+			}
 			break;
 		default:
 			break;
diff --git a/src/tests/Loader/classloader/generics/ByRefLike/ValidateNegative.cs b/src/tests/Loader/classloader/generics/ByRefLike/ValidateNegative.cs
index 20feede256b48..78f091b14acaf 100644
--- a/src/tests/Loader/classloader/generics/ByRefLike/ValidateNegative.cs
+++ b/src/tests/Loader/classloader/generics/ByRefLike/ValidateNegative.cs
@@ -18,7 +18,6 @@ public static void AllowByRefLike_Substituted_For_NonByRefLike_Invalid()
         Console.WriteLine($"{nameof(AllowByRefLike_Substituted_For_NonByRefLike_Invalid)}...");
 
         Assert.Throws<TypeLoadException>(() => { Exec.TypeSubstitutionInterfaceImplementationAllowByRefLikeIntoNonByRefLike(); });
-        Assert.Throws<TypeLoadException>(() => { Exec.TypeSubstitutionFieldAllowByRefLikeIntoNonByRefLike(); });
         Assert.Throws<TypeLoadException>(() => { Exec.OverrideMethodNotByRefLike(); });
     }
 
@@ -28,5 +27,6 @@ public static void AllowByRefLike_Substituted_For_NonByRefLike_Invalid_Class()
         Console.WriteLine($"{nameof(AllowByRefLike_Substituted_For_NonByRefLike_Invalid_Class)}...");
 
         Assert.Throws<TypeLoadException>(() => { Exec.TypeSubstitutionInheritanceAllowByRefLikeIntoNonByRefLike(); });
+        Assert.Throws<TypeLoadException>(() => { Exec.TypeSubstitutionFieldAllowByRefLikeIntoNonByRefLike(); });
     }
 }
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