fix: patch CWA-2023-004 (#343)

* fix: Add function number checks

This is a cherry-pick of 68486ce4d58847f9bb2368e689a4df3ce1f3f388

* fix: Catch panic

This is a cherry-pick of e6979a3d9822766cc0103db44c09b64b5a18e6b4

* build: Set version: 1.1.9+0.9.0

* Revert "build: Set version: 1.1.9+0.9.0"

This reverts commit 0dfb5b2.

---------

Co-authored-by: Christoph Otter <chris@confio.gmbh>

packages/vm/src/compatibility.rs

@@ -1,3 +1,4 @@
+use parity_wasm::elements::Type;
 use parity_wasm::elements::{External, ImportEntry, Module};
 use std::collections::BTreeSet;
 use std::collections::HashSet;
@@ -51,6 +52,12 @@ const SUPPORTED_INTERFACE_VERSIONS: &[&str] = &[
 
 const MEMORY_LIMIT: u32 = 512; // in pages
 
+const MAX_FUNCTIONS: usize = 10000;
+
+const MAX_FUNCTION_PARAMS: usize = 50;
+
+const MAX_FUNCTION_RESULTS: usize = 1;
+
 /// Checks if the data is valid wasm and compatibility with the CosmWasm API (imports and exports)
 pub fn check_wasm(wasm_code: &[u8], available_capabilities: &HashSet<String>) -> VmResult<()> {
     let module = deserialize_wasm(wasm_code)?;
@@ -59,6 +66,8 @@ pub fn check_wasm(wasm_code: &[u8], available_capabilities: &HashSet<String>) ->
     check_wasm_exports(&module)?;
     check_wasm_imports(&module, SUPPORTED_IMPORTS)?;
     check_wasm_capabilities(&module, available_capabilities)?;
+    check_wasm_functions(&module)?;
+
     Ok(())
 }
 
@@ -193,6 +202,51 @@ fn check_wasm_capabilities(
     Ok(())
 }
 
+fn check_wasm_functions(module: &Module) -> VmResult<()> {
+    let functions = module
+        .function_section()
+        .map(|fs| fs.entries())
+        .unwrap_or_default();
+
+    if functions.len() > MAX_FUNCTIONS {
+        return Err(VmError::static_validation_err(format!(
+            "Wasm contract contains more than {MAX_FUNCTIONS} functions"
+        )));
+    }
+
+    let types = module
+        .type_section()
+        .map(|ts| ts.types())
+        .unwrap_or_default();
+
+    let max_func_params = types
+        .iter()
+        .map(|t| match t {
+            Type::Function(f) => f.params().len(),
+        })
+        .max()
+        .unwrap_or_default();
+    let max_func_results = types
+        .iter()
+        .map(|t| match t {
+            Type::Function(f) => f.results().len(),
+        })
+        .max()
+        .unwrap_or_default();
+
+    if max_func_params > MAX_FUNCTION_PARAMS {
+        return Err(VmError::static_validation_err(format!(
+            "Wasm contract contains function with more than {MAX_FUNCTION_PARAMS} parameters"
+        )));
+    }
+    if max_func_results > MAX_FUNCTION_RESULTS {
+        return Err(VmError::static_validation_err(format!(
+            "Wasm contract contains function with more than {MAX_FUNCTION_RESULTS} results"
+        )));
+    }
+    Ok(())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

packages/vm/src/modules/file_system_cache.rs

@@ -1,5 +1,7 @@
 use std::fs;
 use std::io;
+use std::panic::catch_unwind;
+use std::panic::AssertUnwindSafe;
 use std::path::PathBuf;
 
 use wasmer::{DeserializeError, Module, Store};
@@ -124,9 +126,13 @@ impl FileSystemCache {
             .map_err(|e| VmError::cache_err(format!("Error creating directory: {}", e)))?;
         let filename = checksum.to_hex();
         let path = modules_dir.join(filename);
-        module
-            .serialize_to_file(path)
-            .map_err(|e| VmError::cache_err(format!("Error writing module to disk: {}", e)))?;
+
+        catch_unwind(AssertUnwindSafe(|| {
+            module
+                .serialize_to_file(&path)
+                .map_err(|e| VmError::cache_err(format!("Error writing module to disk: {e}")))
+        }))
+        .map_err(|_| VmError::cache_err("Could not write module to disk"))??;
         Ok(())
     }