Merge pull request #10 from Joffref/joffref/fix-memory-leak

Fix OOM issues due to wrong pointer allocation

Makefile

@@ -18,7 +18,7 @@ rust-test: rust-dependencies
 
 wasm:
 	cd $(PROJECT_DIR)/lib && cargo build --target wasm32-unknown-unknown --release
-	mkdir -p $(PROJECT_DIR)/pkg/cedar/static
+	mkdir -p $(PROJECT_DIR)/static
 	cp $(PROJECT_DIR)/lib/target/wasm32-unknown-unknown/release/cedarwasm.wasm $(PROJECT_DIR)/static/cedar.wasm
 
 build: dependencies wasm

api_test.go

@@ -39,7 +39,7 @@ func aHugeAllocationMustReturnAPtr(t *testing.T, module api.Module) {
 
 func twoConcurrentAllocationMustReturnDifferentPtr(t *testing.T, module api.Module) {
 	exportedFuncs := exportFuncs(module)
-	entitiesSize := uint64(100)
+	entitiesSize := uint64(10)
 	entitiesPtr1, err := exportedFuncs[string(allocate)].Call(context.Background(), entitiesSize)
 	if err != nil {
 		t.Fatal(err)

lib/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2021"
 version = "1.0.0"
 
 [dependencies]
-cedar-policy = { version = "2.0" }
+cedar-policy = { version = "2.0.0" }
 wee_alloc = "0.4.5"
 once_cell = "1.17.1"
 

lib/src/interface.rs

@@ -2,7 +2,6 @@ extern crate alloc;
 extern crate core;
 extern crate wee_alloc;
 
-use std::mem::MaybeUninit;
 use cedar_policy::{PolicySet, Entities, Authorizer, EntityUid, Context, Request, Decision};
 
 use std::{slice};
@@ -19,7 +18,7 @@ static mut ENGINE: Lazy<CedarEngine>= Lazy::new(|| {
     }
 });
 
-static mut HEAP: Lazy<HashMap<* mut u8, Box<[MaybeUninit<u8>]>>> = Lazy::new(|| {
+static mut HEAP: Lazy<HashMap<* mut u8, &mut [u8]>> = Lazy::new(|| {
     HashMap::new()
 });
 
@@ -137,18 +136,15 @@ pub unsafe extern "C" fn _allocate(size: u32) -> * mut u8 {
 /// Allocates size bytes and leaks the pointer where they start.
 unsafe fn allocate(size: usize) -> *mut u8 {
     // Allocate the amount of bytes needed.
-    let vec: Vec<MaybeUninit<u8>> = Vec::with_capacity(size);
-
-    let boxed_vec = vec.into_boxed_slice();
+    let vec: Vec<u8> = Vec::with_capacity(size);
 
     // into_raw leaks the memory to the caller.
-    let  ptr = Box::into_raw(Box::from(&boxed_vec)) as *mut u8;
+    let  ptr = vec.as_ptr() as *mut u8;
 
     // Store the boxed_vec to prevent it from being deallocated.
-    HEAP.insert(ptr, boxed_vec);
+    HEAP.insert(ptr, vec.leak());
     // Return the pointer to the caller.
     ptr
-
 }
 
 
@@ -255,9 +251,6 @@ mod test {
     #[test]
      fn allocate_deallocate() {
         unsafe {
-            let zero:u8 = 0;
-            HEAP.insert(zero as *mut u8, Box::new([MaybeUninit::new(0); 10])); // Insert a dummy value to make sure the map is initialized.
-            HEAP.remove(&(zero as *mut u8)).unwrap(); // Remove the dummy value.
             let ptr = allocate(10);
             assert_eq!(HEAP.contains_key(&ptr), true);
             deallocate(ptr, 10);