Merge pull request #9 from binance-chain/issue8

[R4R]fix gov hub do not well handle when the target account is not contract
bnb-chain · May 27, 2020 · 3f966fb · 3f966fb
2 parents ad7c557 + 12a4c16
commit 3f966fb
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Showing 4 changed files with 36 additions and 1 deletion.
diff --git a/contracts/GovHub.sol b/contracts/GovHub.sol
@@ -82,6 +82,10 @@ contract GovHub is System{
         if (target == address(this)){
             updateParam(key, value);
         }else{
+            if (!isContract(target)){
+                emit failReasonWithStr("the target is not a contract");
+                return;
+            }
             try IParamSubscriber(target).updateParam(key, value){
             }catch Error(string memory reason) {
                 emit failReasonWithStr(reason);
@@ -110,4 +114,10 @@ contract GovHub is System{
             emit failReasonWithStr("unknown param");
         }
     }
+
+    function isContract(address addr) internal view returns (bool) {
+        uint size;
+        assembly { size := extcodesize(addr) }
+        return size > 0;
+    }
 }
diff --git a/contracts/GovHub.template b/contracts/GovHub.template
@@ -83,6 +83,10 @@ contract GovHub is System{
         if (target == address(this)){
             updateParam(key, value);
         }else{
+            if (!isContract(target)){
+                emit failReasonWithStr("the target is not a contract");
+                return;
+            }
             try IParamSubscriber(target).updateParam(key, value){
             }catch Error(string memory reason) {
                 emit failReasonWithStr(reason);
@@ -111,4 +115,10 @@ contract GovHub is System{
             emit failReasonWithStr("unknown param");
         }
     }
+
+    function isContract(address addr) internal view returns (bool) {
+        uint size;
+        assembly { size := extcodesize(addr) }
+        return size > 0;
+    }
 }