From bc4c5c5a975f546f1af07e746054ed1d7aa5787e Mon Sep 17 00:00:00 2001
From: Jack May <jack@solana.com>
Date: Thu, 6 Aug 2020 02:35:07 -0700
Subject: [PATCH] Realloc not supported

---
 programs/bpf_loader/src/syscalls.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/programs/bpf_loader/src/syscalls.rs b/programs/bpf_loader/src/syscalls.rs
index 5287752aec..6c4d368b96 100644
--- a/programs/bpf_loader/src/syscalls.rs
+++ b/programs/bpf_loader/src/syscalls.rs
@@ -879,6 +879,12 @@ fn call<'a>(
         let account = account.borrow();
         if message.is_writable(i) && !account.executable {
             *lamport_ref = account.lamports;
+            if data.len() != account.data.len() {
+                return Err(SyscallError::InstructionError(
+                    InstructionError::AccountDataSizeChanged,
+                )
+                .into());
+            }
             data.clone_from_slice(&account.data);
         }
     }