Diff from https://github.com/JumpCrypto/security-research/blob/master/advisories/2023-003-cosmwasm.md

malicious_alloc_implementation.diff

diff --git a/packages/std/src/memory.rs b/packages/std/src/memory.rs
index c331a53c..09462d25 100644
--- a/packages/std/src/memory.rs
+++ b/packages/std/src/memory.rs
@@ -15,9 +15,21 @@ pub struct Region {
     pub length: u32,
 }
 
+
+extern "C" {
+    fn addr_validate(source_ptr: u32) -> u32;
+}
+
 /// Creates a memory region of capacity `size` and length 0. Returns a pointer to the Region.
 /// This is the same as the `allocate` export, but designed to be called internally.
 pub fn alloc(size: usize) -> *mut Region {
+
+    let source = build_region("".as_bytes());
+    let source_ptr = &*source as *const Region as u32;
+
+    let result = unsafe { addr_validate(source_ptr) };
+
+
     let data: Vec<u8> = Vec::with_capacity(size);
     let data_ptr = data.as_ptr() as usize;