From c9de0fbd29ad4559d64a467b68fdd1906bd34671 Mon Sep 17 00:00:00 2001
From: coffeepots <coffeepotsgh@gmail.com>
Date: Thu, 16 Aug 2018 20:19:53 +0100
Subject: [PATCH] Reduce range of cleanMemRef

---
 nimbus/vm/interpreter/opcodes_impl.nim | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/nimbus/vm/interpreter/opcodes_impl.nim b/nimbus/vm/interpreter/opcodes_impl.nim
index 407fad8a2..e7bceb8c0 100644
--- a/nimbus/vm/interpreter/opcodes_impl.nim
+++ b/nimbus/vm/interpreter/opcodes_impl.nim
@@ -235,9 +235,10 @@ proc writePaddedResult(mem: var Memory,
 func cleanMemRef(x: UInt256): int {.inline.} =
   ## Sanitize memory addresses, catch negative or impossibly big offsets
   # See https://github.com/status-im/nimbus/pull/97 for more info
-  const upperBound = high(int32).u256
+  # For rational on shr, see https://github.com/status-im/nimbus/pull/101
+  const upperBound = (high(int32) shr 2).u256
   if x > upperBound:
-    return high(int32)
+    return high(int32) shr 2
   return x.toInt
 
 op address, inline = true: