From 315b87c718d6c8dc9c60b48cf1c5bf24d22184de Mon Sep 17 00:00:00 2001
From: Patrick Ventuzelo <ventuzelo.patrick@gmail.com>
Date: Wed, 18 Sep 2019 10:28:49 +0200
Subject: [PATCH] check index before accessing imports.globals

---
 lib/runtime-core/src/backing.rs | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/lib/runtime-core/src/backing.rs b/lib/runtime-core/src/backing.rs
index 814dc56e7..710471d15 100644
--- a/lib/runtime-core/src/backing.rs
+++ b/lib/runtime-core/src/backing.rs
@@ -149,6 +149,11 @@ impl LocalBacking {
                     }]);
                 }
                 Initializer::GetGlobal(import_global_index) => {
+                    if import_global_index.index() >= imports.globals.len() {
+                        return Err(vec![LinkError::Generic {
+                            message: "incorrect global index for initializer".to_string(),
+                        }]);
+                    }
                     if let Value::I32(x) = imports.globals[import_global_index].get() {
                         x as u32
                     } else {
@@ -205,6 +210,11 @@ impl LocalBacking {
                     }]);
                 }
                 Initializer::GetGlobal(import_global_index) => {
+                    if import_global_index.index() >= imports.globals.len() {
+                        return Err(vec![LinkError::Generic {
+                            message: "incorrect global index for initializer".to_string(),
+                        }]);
+                    }
                     if let Value::I32(x) = imports.globals[import_global_index].get() {
                         x as u32
                     } else {
@@ -273,6 +283,11 @@ impl LocalBacking {
                     }]);
                 }
                 Initializer::GetGlobal(import_global_index) => {
+                    if import_global_index.index() >= imports.globals.len() {
+                        return Err(vec![LinkError::Generic {
+                            message: "incorrect global index for initializer".to_string(),
+                        }]);
+                    }
                     if let Value::I32(x) = imports.globals[import_global_index].get() {
                         x as u32
                     } else {
@@ -326,6 +341,11 @@ impl LocalBacking {
                     }]);
                 }
                 Initializer::GetGlobal(import_global_index) => {
+                    if import_global_index.index() >= imports.globals.len() {
+                        return Err(vec![LinkError::Generic {
+                            message: "incorrect global index for initializer".to_string(),
+                        }]);
+                    }
                     if let Value::I32(x) = imports.globals[import_global_index].get() {
                         x as u32
                     } else {