bug: Integer overflow while calculating the remaining gas in GasInspe…

…ctor (#287)
bluealloy · Dec 7, 2022 · 54e0333 · 54e0333
1 parent acdbaac
commit 54e0333
Show file tree

Hide file tree

Showing 4 changed files with 38 additions and 6 deletions.
diff --git a/bins/revme/src/statetest/runner.rs b/bins/revme/src/statetest/runner.rs
@@ -277,8 +277,7 @@ pub fn execute_test_suit(path: &Path, elapsed: &Arc<Mutex<Duration>>) -> Result<
                     let db = evm.db().unwrap();
                     println!("{path:?} UNIT_TEST:{name}\n");
                     println!(
-                        "failed reason: {:?} {:?} UNIT_TEST:{}\n gas:{:?} ({:?} refunded)",
-                        exit_reason, path, name, gas_used, gas_refunded,
+                        "failed reason: {exit_reason:?} {path:?} UNIT_TEST:{name}\n gas:{gas_used:?} ({gas_refunded:?} refunded)"
                     );
                     println!("\nApplied state:{db:?}\n");
                     println!("\nStateroot: {state_root:?}\n");

diff --git a/bins/revme/src/statetest/trace.rs b/bins/revme/src/statetest/trace.rs
@@ -49,7 +49,7 @@ impl<DB: Database> Inspector<DB> for CustomPrintTracer {
             interp.program_counter(),
             gas_remaining,
             gas_remaining,
-            opcode_str.unwrap(),
+            opcode_str.unwrap_or("UNKNOWN"),
             opcode,
             interp.gas.refunded(),
             interp.gas.refunded(),
@@ -139,3 +139,35 @@ impl<DB: Database> Inspector<DB> for CustomPrintTracer {
         println!("SELFDESTRUCT on "); //{:?} target: {:?}", address, target);
     }
 }
+
+#[cfg(test)]
+mod test {
+
+    use super::*;
+    use hex_literal::hex;
+    use revm::{common::keccak256, Bytecode, TransactTo, U256};
+
+    #[test]
+    fn gas_calculation_underflow() {
+        // https://github.com/bluealloy/revm/issues/277
+        // checks this usecase
+        let mut evm = revm::new();
+        let mut database = revm::InMemoryDB::default();
+        let code: Bytes = hex::decode("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").unwrap().into();
+
+        let acc_info = revm::AccountInfo {
+            balance: "0x100c5d668240db8e00".parse().unwrap(),
+            code_hash: keccak256(&code),
+            code: Some(Bytecode::new_raw(code.clone())),
+            nonce: "1".parse().unwrap(),
+        };
+        let callee = hex!("5fdcca53617f4d2b9134b29090c87d01058e27e9");
+        database.insert_account_info(B160(callee), acc_info);
+        evm.database(database);
+        evm.env.tx.caller = B160(hex!("5fdcca53617f4d2b9134b29090c87d01058e27e0"));
+        evm.env.tx.transact_to = TransactTo::Call(B160(callee));
+        evm.env.tx.data = Bytes::from(hex::decode("").unwrap());
+        evm.env.tx.value = U256::ZERO;
+        evm.inspect_commit(CustomPrintTracer::new());
+    }
+}
diff --git a/crates/revm/src/bits.rs b/crates/revm/src/bits.rs
@@ -148,7 +148,7 @@ mod serialize {
         fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
             match *self {
                 Self::InvalidHex { character, index } => {
-                    write!(fmt, "invalid hex character: {}, at {}", character, index)
+                    write!(fmt, "invalid hex character: {character}, at {index}")
                 }
             }
         }

diff --git a/crates/revm/src/inspector.rs b/crates/revm/src/inspector.rs
@@ -202,11 +202,12 @@ impl<DB: Database> Inspector<DB> for GasInspector {
         } else if self.was_return {
             // we are ok to decrement PC by one as it is return of call
             let previous_pc = pc - 1;
+            self.reduced_gas_block = 0;
             self.full_gas_block = interp.contract.gas_block(previous_pc);
             self.was_return = false;
         }
-
-        self.gas_remaining = interp.gas.remaining() + self.full_gas_block - self.reduced_gas_block;
+        self.gas_remaining =
+            interp.gas.remaining() + (self.full_gas_block - self.reduced_gas_block);
 
         Return::Continue
     }