Fix OOM bug: UTXO entries with invalid script length

Author: sipa

src/compressor.h

@@ -86,8 +86,14 @@ class CScriptCompressor
             return;
         }
         nSize -= nSpecialScripts;
-        script.resize(nSize);
-        s >> REF(CFlatData(script));
+        if (nSize > MAX_SCRIPT_SIZE) {
+            // Overly long script, replace with a short invalid one
+            script << OP_RETURN;
+            s.ignore(nSize);
+        } else {
+            script.resize(nSize);
+            s >> REF(CFlatData(script));
+        }
     }
 };
 

src/streams.h

@@ -406,6 +406,20 @@ class CAutoFile
         return (*this);
     }
 
+    CAutoFile& ignore(size_t nSize)
+    {
+        if (!file)
+            throw std::ios_base::failure("CAutoFile::ignore: file handle is NULL");
+        unsigned char data[4096];
+        while (nSize > 0) {
+            size_t nNow = std::min<size_t>(nSize, sizeof(data));
+            if (fread(data, 1, nNow, file) != nNow)
+                throw std::ios_base::failure(feof(file) ? "CAutoFile::ignore: end of file" : "CAutoFile::read: fread failed");
+            nSize -= nNow;
+        }
+        return (*this);
+    }
+
     CAutoFile& write(const char* pch, size_t nSize)
     {
         if (!file)