Do not ignore status byte on VM step / in the chal solver

op-challenger/game/fault/solver/solver.go

@@ -133,7 +133,7 @@ func (s *Solver) defend(ctx context.Context, claim types.Claim) (*types.Claim, e
 // agreeWithClaim returns true if the claim is correct according to the internal [TraceProvider].
 func (s *Solver) agreeWithClaim(ctx context.Context, claim types.ClaimData) (bool, error) {
 	ourValue, err := s.traceAtPosition(ctx, claim.Position)
-	return bytes.Equal(ourValue[1:], claim.Value[1:]), err
+	return bytes.Equal(ourValue[:], claim.Value[:]), err
 }
 
 // traceAtPosition returns the [common.Hash] from internal [TraceProvider] at the given [Position].

packages/contracts-bedrock/.gas-snapshot

@@ -88,16 +88,16 @@ FaucetTest:test_nonAdmin_drip_fails() (gas: 262520)
 FaucetTest:test_receive_succeeds() (gas: 17401)
 FaucetTest:test_withdraw_nonAdmin_reverts() (gas: 13145)
 FaucetTest:test_withdraw_succeeds() (gas: 78359)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot1:test_resolvesCorrectly_succeeds() (gas: 509676)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot2:test_resolvesCorrectly_succeeds() (gas: 516934)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot3:test_resolvesCorrectly_succeeds() (gas: 513235)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot4:test_resolvesCorrectly_succeeds() (gas: 516475)
-FaultDisputeGame_ResolvesCorrectly_CorrectRoot5:test_resolvesCorrectly_succeeds() (gas: 514814)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot1:test_resolvesCorrectly_succeeds() (gas: 508441)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot2:test_resolvesCorrectly_succeeds() (gas: 515699)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot3:test_resolvesCorrectly_succeeds() (gas: 512000)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot4:test_resolvesCorrectly_succeeds() (gas: 513240)
-FaultDisputeGame_ResolvesCorrectly_IncorrectRoot5:test_resolvesCorrectly_succeeds() (gas: 511579)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot1:test_resolvesCorrectly_succeeds() (gas: 509652)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot2:test_resolvesCorrectly_succeeds() (gas: 516910)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot3:test_resolvesCorrectly_succeeds() (gas: 513211)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot4:test_resolvesCorrectly_succeeds() (gas: 516451)
+FaultDisputeGame_ResolvesCorrectly_CorrectRoot5:test_resolvesCorrectly_succeeds() (gas: 514790)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot1:test_resolvesCorrectly_succeeds() (gas: 508417)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot2:test_resolvesCorrectly_succeeds() (gas: 515675)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot3:test_resolvesCorrectly_succeeds() (gas: 511976)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot4:test_resolvesCorrectly_succeeds() (gas: 513216)
+FaultDisputeGame_ResolvesCorrectly_IncorrectRoot5:test_resolvesCorrectly_succeeds() (gas: 511555)
 FaultDisputeGame_Test:test_addLocalData_static_succeeds() (gas: 640504)
 FaultDisputeGame_Test:test_createdAt_succeeds() (gas: 10342)
 FaultDisputeGame_Test:test_extraData_succeeds() (gas: 32377)

packages/contracts-bedrock/semver-lock.json

@@ -16,7 +16,7 @@
   "src/L2/L2StandardBridge.sol": "0xe025dcccbf21d48828ecf588941c9ba04c91b87bdd177a653d3f1b265b0b02a8",
   "src/L2/L2ToL1MessagePasser.sol": "0xda56ba2e5b2c28fa8ca2df24077d49e96155a00ecc99cd0778d681be6ed166fe",
   "src/L2/SequencerFeeVault.sol": "0x37816035c992d38cf7e3d5a1846b02d017dd7bdca46abe6e5c5171b9ee6225ab",
-  "src/dispute/FaultDisputeGame.sol": "0x80a0571e79b452c086e5432606c26ff548d2ae4443d0836833302c2989b0a1ea",
+  "src/dispute/FaultDisputeGame.sol": "0x43a8ef33b55a90532760cf4062038fe548aa68316457520bcf64e206a160a453",
   "src/legacy/DeployerWhitelist.sol": "0xf2129ec3da75307ba8e21bc943c332bb04704642e6e263149b5c8ee92dbcb7a8",
   "src/legacy/L1BlockNumber.sol": "0x30aae1fc85103476af0226b6e98c71c01feebbdc35d93401390b1ad438a37be6",
   "src/legacy/LegacyMessagePasser.sol": "0x5c08b0a663cc49d30e4e38540f6aefab19ef287c3ecd31c8d8c3decd5f5bd497",

packages/contracts-bedrock/src/dispute/FaultDisputeGame.sol

@@ -167,11 +167,7 @@ contract FaultDisputeGame is IFaultDisputeGame, Clone, Semver {
         // SAFETY:    While the `attack` path does not need an extra check for the post
         //            state's depth in relation to the parent, we don't need another
         //            branch because (n - n) % 2 == 0.
-        //            We ignore the highest order byte of the digest because it is used to
-        //            indicate the VM Status and is added after the digest is computed. The
-        //            hash commits to the exit code and the exit status, so the VM status does
-        //            not need to be checked for equivalence.
-        bool validStep = (VM.step(_stateData, _proof)) << 8 == (Claim.unwrap(postState.claim) << 8);
+        bool validStep = VM.step(_stateData, _proof) == Claim.unwrap(postState.claim);
         bool parentPostAgree = (parentPos.depth() - postState.position.depth()) % 2 == 0;
         if (parentPostAgree == validStep) revert ValidStep();