question:so now let's move to confirm vulnerability i found this vulnerability but not all valid and correct so review them and review the contract and give the validity of every vulnerability with evidence and prove if it's correct and valid or invalid with evidence and give the vulnerable line with code and with explanation -issue 1 this reentrancy attack occurs when a contract makes an external call to another untrusted contract before it resolves its own state. An attacker can take advantage of the external call to re-enter the original function and modify the state in an unexpected way. In the context of the GuardCM contract, the _processBridgeData function makes external calls to decode and verify bridged data. If any of the called contracts are malicious, they could potentially re-enter the GuardCM contract and manipulate the state (e.g., altering the paused state or modifying authorization mappings) before the initial execution is completed. - and this Delegatecall is a feature in Solidity that allows a contract to execute code in the context of its own storage using the code from another contract. An attacker could exploit this by tricking a contract into executing a delegatecall to a malicious contract, potentially leading to state manipulation or logic takeover. The GuardCM contract explicitly prohibits delegatecalls to the owner (Timelock) in the checkTransaction function, which is a security measure to prevent such attacks. However, if there are any other functions or fallback mechanisms that do not properly restrict or handle delegatecalls, the contract could be vulnerable to this type of attack.- and this Phishing attacks involve tricking individuals into taking actions that compromise security, such as revealing sensitive information or approving malicious transactions. In the context of the GuardCM contract, an attacker could create a seemingly legitimate governance proposal that, if executed, would interact with the contract in a harmful way, such as altering its state or redirecting funds. The contract relies on external governance for certain operations, like pausing the guard, which could be exploited if governance participants are not vigilant. - and this An authorization bypass attack occurs when an attacker exploits flaws in a system's access control to perform actions they are not permitted to do. In the GuardCM contract, the setBridgeMediatorChainIds function allows the owner to link L1 bridge mediators to corresponding L2 bridge mediators and chain IDs. If an attacker gains control over the owner account or finds a way to manipulate this mapping, they could potentially register a malicious L2 bridge mediator. This could allow unauthorized transactions to be processed through the _processBridgeData function, bypassing the contract's security checks. - and this A Denial of Service (DoS) attack aims to make a resource unavailable to its intended users. In the GuardCM contract, the _verifyData, _verifyBridgedData, and _verifySchedule functions check for specific data lengths when processing transactions. If an attacker can craft a transaction with incorrect data lengths that do not meet the expected criteria, it could cause the contract to revert, potentially blocking legitimate transactions if the contract does not handle such cases gracefully.- and this An attacker could potentially manipulate the governance proposal check mechanism to pause the guard. If the attacker can influence the state of a governance proposal (governorCheckProposalId) to be Defeated, they could trigger the pause function even if the governance is active. This could be done by creating a proposal that is designed to fail or by other means of manipulating the voting process. Once the guard is paused, the attacker could execute unauthorized transactions without the usual checks and restrictions. her eis the contract to confirm and too give correct answer with evidence that is the importance // SPDX-License-Identifier: MIT pragma solidity ^0.8.23; import {Enum} from "@gnosis.pm/safe-contracts/contracts/common/Enum.sol"; interface IGovernor { function state(uint256 proposalId) external returns (ProposalState); } // Governor proposal state enum ProposalState { Pending, Active, Canceled, Defeated, Succeeded, Queued, Expired, Executed } /// @dev Only `owner` has a privilege, but the `sender` was provided. /// @param sender Sender address. /// @param owner Required sender address as an owner. error OwnerOnly(address sender, address owner); /// @dev Only `manager` has a privilege, but the `sender` was provided. /// @param sender Sender address. /// @param manager Required sender address as an owner. error ManagerOnly(address sender, address manager); /// @dev Provided zero address. error ZeroAddress(); /// @dev Provided zero value. error ZeroValue(); /// @dev Wrong length of two arrays. /// @param numValues1 Number of values in a first array. /// @param numValues2 Numberf of values in a second array. /// @param numValues3 Numberf of values in a third array. /// @param numValues4 Numberf of values in a fourth array. error WrongArrayLength(uint256 numValues1, uint256 numValues2, uint256 numValues3, uint256 numValues4); /// @dev Provided bridged mediator is not unique. /// @param bridgeMediator Bridge mediator address. error BridgeMediatorNotUnique(address bridgeMediator); /// @dev Provided incorrect data length. /// @param expected Expected minimum data length. /// @param provided Provided data length. error IncorrectDataLength(uint256 expected, uint256 provided); /// @dev No delegatecall is allowed. error NoDelegateCall(); /// @dev No self multisig call is allowed. error NoSelfCall(); /// @dev The combination of target and selector is not authorized. /// @param target Target address. /// @param selector Function selector. /// @param chainId Chain Id. error NotAuthorized(address target, bytes4 selector, uint256 chainId); /// @dev The proposal is not defeated. /// @param proposalId Proposal Id. /// @param state Current proposal state. error NotDefeated(uint256 proposalId, ProposalState state); /// @dev Passed L2 chain Id is not supported. /// @param chainId L2 chain Id. error L2ChainIdNotSupported(uint256 chainId); /// @dev Provided wrong function selector. /// @param functionSig Function selector. /// @param chainId Chain Id. error WrongSelector(bytes4 functionSig, uint256 chainId); /// @dev Provided wrong L2 bridge mediator address. /// @param provided Provided address. /// @param expected Expected address. error WrongL2BridgeMediator(address provided, address expected); /// @title GuardCM - Smart contract for Gnosis Safe community multisig (CM) guard /// @author Aleksandr Kuperman - <[email protected]> /// @author Andrey Lebedev - <<PRESIDIO_ANONYMIZED_EMAIL_ADDRESS>> contract GuardCM { event GovernorUpdated(address indexed governor); event SetTargetSelectors(address[] indexed targets, bytes4[] indexed selectors, uint256[] chainIds, bool[] statuses); event SetBridgeMediators(address[] indexed bridgeMediatorL1s, address[] indexed bridgeMediatorL2s, uint256[] chainIds); event GovernorCheckProposalIdChanged(uint256 indexed proposalId); event GuardPaused(address indexed account); event GuardUnpaused(); // schedule selector bytes4 public constant SCHEDULE = bytes4(keccak256(bytes("schedule(address,uint256,bytes,bytes32,bytes32,uint256)"))); // scheduleBatch selector bytes4 public constant SCHEDULE_BATCH = bytes4(keccak256(bytes("scheduleBatch(address[],uint256[],bytes[],bytes32,bytes32,uint256)"))); // requireToPassMessage selector (Gnosis chain) bytes4 public constant REQUIRE_TO_PASS_MESSAGE = bytes4(keccak256(bytes("requireToPassMessage(address,bytes,uint256)"))); // processMessageFromForeign selector (Gnosis chain) bytes4 public constant PROCESS_MESSAGE_FROM_FOREIGN = bytes4(keccak256(bytes("processMessageFromForeign(bytes)"))); // sendMessageToChild selector (Polygon) bytes4 public constant SEND_MESSAGE_TO_CHILD = bytes4(keccak256(bytes("sendMessageToChild(address,bytes)"))); // Initial check governance proposal Id // Calculated from the proposalHash function of the GovernorOLAS uint256 public governorCheckProposalId = 88250008686885504216650933897987879122244685460173810624866685274624741477673; // Minimum data length that is encoded for the schedule function, // plus at least 4 bytes or 32 bits for the selector from the payload uint256 public constant MIN_SCHEDULE_DATA_LENGTH = 260; // Minimum data length that contains at least a selector (4 bytes or 32 bits) uint256 public constant SELECTOR_DATA_LENGTH = 4; // Minimum payload length for message on Gnosis accounting for all required encoding and at least one selector uint256 public constant MIN_GNOSIS_PAYLOAD_LENGTH = 292; // Minimum payload length for message on Polygon accounting for all required encoding and at least one selector uint256 public constant MIN_POLYGON_PAYLOAD_LENGTH = 164; // Owner address address public immutable owner; // Multisig address address public immutable multisig; // Governor address address public governor; // Guard pausing possibility uint8 public paused = 1; // Mapping of (target address | bytes4 selector | uint64 chain Id) => enabled / disabled mapping(uint256 => bool) public mapAllowedTargetSelectorChainIds; // Mapping of bridge mediator address L1 => (bridge mediator L2 address | uint64 supported L2 chain Id) mapping(address => uint256) public mapBridgeMediatorL1L2ChainIds; /// @dev GuardCM constructor. /// @param _timelock Timelock address. /// @param _multisig Community multisig address. /// @param _governor Governor address. constructor( address _timelock, address _multisig, address _governor ) { // Check for zero addresses if (_timelock == address(0) || _multisig == address(0) || _governor == address(0)) { revert ZeroAddress(); } owner = _timelock; multisig = _multisig; governor = _governor; } /// @dev Changes the governor. /// @param newGovernor Address of a new governor. function changeGovernor(address newGovernor) external { if (msg.sender != owner) { revert OwnerOnly(msg.sender, owner); } // Check for the zero address if (newGovernor == address(0)) { revert ZeroAddress(); } governor = newGovernor; emit GovernorUpdated(newGovernor); } /// @dev Changes the governor check proposal Id. /// @param proposalId Governor check proposal Id. function changeGovernorCheckProposalId(uint256 proposalId) external { if (msg.sender != owner) { revert OwnerOnly(msg.sender, owner); } // Check for the zero value if (proposalId == 0) { revert ZeroValue(); } governorCheckProposalId = proposalId; emit GovernorCheckProposalIdChanged(proposalId); } /// @dev Verifies authorized combinations of target and selector. /// @notice The bottom-most internal function is still not "view" since some reverts are not explicitly handled /// @param target Target address. /// @param data Payload bytes. /// @param chainId Chain Id. function _verifyData(address target, bytes memory data, uint256 chainId) internal { // Push a pair of key defining variables into one key // target occupies first 160 bits uint256 targetSelectorChainId = uint256(uint160(target)); // selector occupies next 32 bits targetSelectorChainId |= uint256(uint32(bytes4(data))) << 160; // chainId occupies next 64 bits targetSelectorChainId |= chainId << 192; // Check the authorized combination of target and selector if (!mapAllowedTargetSelectorChainIds[targetSelectorChainId]) { revert NotAuthorized(target, bytes4(data), chainId); } } /// @dev Verifies the bridged data for authorized combinations of targets and selectors. /// @notice The processed data is packed as a set of bytes that are assembled using the following parameters: /// address target, uint96 value, uint32 payloadLength, bytes payload. /// @param data Payload bytes. /// @param chainId L2 chain Id. function _verifyBridgedData(bytes memory data, uint256 chainId) internal { // Unpack and process the data // We need to skip first 12 bytes as those are zeros from encoding for (uint256 i = 0; i < data.length;) { address target; uint32 payloadLength; // solhint-disable-next-line no-inline-assembly assembly { // First 20 bytes is the address (160 bits) i := add(i, 20) target := mload(add(data, i)) // Offset the data by 12 bytes of value (96 bits) and by 4 bytes of payload length (32 bits) i := add(i, 16) payloadLength := mload(add(data, i)) } // Check for the zero address if (target == address(0)) { revert ZeroAddress(); } // The payload length must be at least of the a function selector size if (payloadLength < SELECTOR_DATA_LENGTH) { revert IncorrectDataLength(payloadLength, SELECTOR_DATA_LENGTH); } // Get the payload bytes memory payload = new bytes(payloadLength); for (uint256 j = 0; j < payloadLength; ++j) { payload[j] = data[i + j]; } // Offset the data by the payload number of bytes i += payloadLength; // Verify the scope of the data _verifyData(target, payload, chainId); } } /// @dev Processes bridged data: checks the header and verifies the payload. /// @param data Full data bytes with the header. /// @param bridgeMediatorL2 Address of a bridged mediator on L2. /// @param chainId L2 chain Id. function _processBridgeData( bytes memory data, address bridgeMediatorL2, uint256 chainId ) internal { // Gnosis chains if (chainId == 100 || chainId == 10200) { // Check the L1 initial selector bytes4 functionSig = bytes4(data); if (functionSig != REQUIRE_TO_PASS_MESSAGE) { revert WrongSelector(functionSig, chainId); } // Check if the data length is less than a size of a selector plus the message minimum payload size if (data.length < MIN_GNOSIS_PAYLOAD_LENGTH) { revert IncorrectDataLength(data.length, MIN_GNOSIS_PAYLOAD_LENGTH); } // Copy the data without the selector bytes memory payload = new bytes(data.length - SELECTOR_DATA_LENGTH); for (uint256 i = 0; i < payload.length; ++i) { payload[i] = data[i + 4]; } // Decode the requireToPassMessage payload: homeMediator (L2), mediatorPayload (need decoding), requestGasLimit (address homeMediator, bytes memory mediatorPayload, ) = abi.decode(payload, (address, bytes, uint256)); // Check that the home mediator matches the L2 bridge mediator address if (homeMediator != bridgeMediatorL2) { revert WrongL2BridgeMediator(homeMediator, bridgeMediatorL2); } // Check the L2 initial selector functionSig = bytes4(mediatorPayload); if (functionSig != PROCESS_MESSAGE_FROM_FOREIGN) { revert WrongSelector(functionSig, chainId); } // Copy the data without a selector bytes memory bridgePayload = new bytes(mediatorPayload.length - SELECTOR_DATA_LENGTH); for (uint256 i = 0; i < bridgePayload.length; ++i) { bridgePayload[i] = mediatorPayload[i + SELECTOR_DATA_LENGTH]; } // Decode the processMessageFromForeign payload: l2Message (executed on L2) (bytes memory l2Message) = abi.decode(bridgePayload, (bytes)); // Verify processMessageFromForeign payload _verifyBridgedData(l2Message, chainId); } // Polygon chains if (chainId == 137 || chainId == 80001) { // Check the L1 initial selector bytes4 functionSig = bytes4(data); if (functionSig != SEND_MESSAGE_TO_CHILD) { revert WrongSelector(functionSig, chainId); } // Check if the data length is less than a size of a selector plus the message minimum payload size if (data.length < MIN_POLYGON_PAYLOAD_LENGTH) { revert IncorrectDataLength(data.length, MIN_POLYGON_PAYLOAD_LENGTH); } // Copy the data without the selector bytes memory payload = new bytes(data.length - SELECTOR_DATA_LENGTH); for (uint256 i = 0; i < payload.length; ++i) { payload[i] = data[i + SELECTOR_DATA_LENGTH]; } // Decode sendMessageToChild payload: fxGovernorTunnel (L2), l2Message (executed on L2) (address fxGovernorTunnel, bytes memory l2Message) = abi.decode(payload, (address, bytes)); // Check that the fxGovernorTunnel matches the L2 bridge mediator address if (fxGovernorTunnel != bridgeMediatorL2) { revert WrongL2BridgeMediator(fxGovernorTunnel, bridgeMediatorL2); } // Verify sendMessageToChild payload _verifyBridgedData(l2Message, chainId); } } /// @dev Verifies authorized target and selector in the schedule or scheduleBatch function call. /// @param data Data in bytes. /// @param selector Schedule function selector. function _verifySchedule(bytes memory data, bytes4 selector) internal { // Copy the data without the selector bytes memory payload = new bytes(data.length - SELECTOR_DATA_LENGTH); for (uint256 i = 0; i < payload.length; ++i) { payload[i] = data[i + 4]; } // Prepare the decoding data sets address[] memory targets; bytes[] memory callDatas; if (selector == SCHEDULE) { targets = new address[](1); callDatas = new bytes[](1); // Decode the data in the schedule function (targets[0], , callDatas[0], , , ) = abi.decode(payload, (address, uint256, bytes, bytes32, bytes32, uint256)); } else { // Decode the data in the scheduleBatch function (targets, , callDatas, , , ) = abi.decode(payload, (address[], uint256[], bytes[], bytes32, bytes32, uint256)); } // Traverse all the schedule targets and selectors extracted from calldatas for (uint i = 0; i < targets.length; ++i) { // Get the bridgeMediatorL2 and L2 chain Id, if any uint256 bridgeMediatorL2ChainId = mapBridgeMediatorL1L2ChainIds[targets[i]]; // bridgeMediatorL2 occupies first 160 bits address bridgeMediatorL2 = address(uint160(bridgeMediatorL2ChainId)); // Check if the data goes across the bridge if (bridgeMediatorL2 != address(0)) { // Get the chain Id // L2 chain Id occupies next 64 bits uint256 chainId = bridgeMediatorL2ChainId >> 160; // Process the bridge logic _processBridgeData(callDatas[i], bridgeMediatorL2, chainId); } else { // Verify the data right away as it is not the bridged one _verifyData(targets[i], callDatas[i], block.chainid); } } } /// @dev Checks the transaction for authorized arguments. /// @notice Scheduling in timelock is checked against authorized targets and signatures. /// @notice No self-multisig function calls are allowed. /// @param to Destination address of Safe transaction. /// @param data Data payload of Safe transaction. /// @param operation Operation type of Safe transaction. function checkTransaction( address to, uint256, bytes memory data, Enum.Operation operation, uint256, uint256, uint256, address, address payable, bytes memory, address ) external { // Just return if paused if (paused == 1) { // Call to the timelock if (to == owner) { // No delegatecall is allowed if (operation == Enum.Operation.DelegateCall) { revert NoDelegateCall(); } // Data needs to have enough bytes at least to fit the selector if (data.length < SELECTOR_DATA_LENGTH) { revert IncorrectDataLength(data.length, SELECTOR_DATA_LENGTH); } // Get the function signature bytes4 functionSig = bytes4(data); // Check the schedule or scheduleBatch function authorized parameters // All other functions are not checked for if (functionSig == SCHEDULE || functionSig == SCHEDULE_BATCH) { // Data length is too short: need to have enough bytes for the schedule() function // with one selector extracted from the payload if (data.length < MIN_SCHEDULE_DATA_LENGTH) { revert IncorrectDataLength(data.length, MIN_SCHEDULE_DATA_LENGTH); } _verifySchedule(data, functionSig); } } else if (to == multisig) { // No self multisig call is allowed revert NoSelfCall(); } } } /// @dev Authorizes combinations of targets, selectors and chain Ids. /// @notice It is the contract owner responsibility to set correct L1 chain Ids where the contract is deployed /// and corresponding supported L2-s, if the contract interacts with them. /// @param targets Array of target addresses. /// @param selectors Array of selectors for targets. /// @param chainIds Chain Ids for authorized functions. /// @param statuses Authorize if true, and restrict otherwise. function setTargetSelectorChainIds( address[] memory targets, bytes4[] memory selectors, uint256[] memory chainIds, bool[] memory statuses ) external { // Check for the ownership if (msg.sender != owner) { revert OwnerOnly(msg.sender, owner); } // Check array length if (targets.length != selectors.length || targets.length != statuses.length || targets.length != chainIds.length) { revert WrongArrayLength(targets.length, selectors.length, statuses.length, chainIds.length); } // Traverse all the targets and selectors to build their paired values for (uint256 i = 0; i < targets.length; ++i) { // Check for zero address targets if (targets[i] == address(0)) { revert ZeroAddress(); } // Check selector for zero selector value if (selectors[i] == bytes4(0)) { revert ZeroValue(); } // Check chain Ids to be greater than zero if (chainIds[i] == 0) { revert ZeroValue(); } // Push a pair of key defining variables into one key // target occupies first 160 bits uint256 targetSelectorChainId = uint256(uint160(targets[i])); // selector occupies next 32 bits targetSelectorChainId |= uint256(uint32(selectors[i])) << 160; // chainId occupies next 64 bits targetSelectorChainId |= chainIds[i] << 192; // Set the status of the target and selector combination mapAllowedTargetSelectorChainIds[targetSelectorChainId] = statuses[i]; } emit SetTargetSelectors(targets, selectors, chainIds, statuses); } /// @dev Sets bridge mediator contracts addresses and L2 chain Ids. /// @notice It is the contract owner responsibility to set correct L1 bridge mediator contracts, /// corresponding L2 bridge mediator contracts, and supported chain Ids. /// @param bridgeMediatorL1s Bridge mediator contract addresses on L1. /// @param bridgeMediatorL2s Corresponding bridge mediator contract addresses on L2. /// @param chainIds Corresponding L2 chain Ids. function setBridgeMediatorChainIds( address[] memory bridgeMediatorL1s, address[] memory bridgeMediatorL2s, uint256[] memory chainIds ) external { // Check for the ownership if (msg.sender != owner) { revert OwnerOnly(msg.sender, owner); } // Check for array correctness if (bridgeMediatorL1s.length != bridgeMediatorL2s.length || bridgeMediatorL1s.length != chainIds.length) { revert WrongArrayLength(bridgeMediatorL1s.length, bridgeMediatorL2s.length, chainIds.length, chainIds.length); } // Link L1 and L2 bridge mediators, set L2 chain Ids for (uint256 i = 0; i < chainIds.length; ++i) { // Check for zero addresses if (bridgeMediatorL1s[i] == address(0) || bridgeMediatorL2s[i] == address(0)) { revert ZeroAddress(); } // Check supported chain Ids on L2 uint256 chainId = chainIds[i]; if (chainId != 100 && chainId != 137 && chainId != 10200 && chainId != 80001) { revert L2ChainIdNotSupported(chainId); } // Push a pair of key defining variables into one key // bridgeMediatorL2 occupies first 160 bits uint256 bridgeMediatorL2ChainId = uint256(uint160(bridgeMediatorL2s[i])); // L2 chain Id occupies next 64 bits bridgeMediatorL2ChainId |= chainId << 160; mapBridgeMediatorL1L2ChainIds[bridgeMediatorL1s[i]] = bridgeMediatorL2ChainId; } emit SetBridgeMediators(bridgeMediatorL1s, bridgeMediatorL2s, chainIds); } /// @dev Pauses the guard restoring a full CM functionality. /// @notice The timeline is able to pause the guard via the voting. /// @notice The CM can request pausing the guard is there was a proposal to check if the governance is alive. /// If the proposal is defeated (not enough votes or never voted on), /// the governance is considered inactive for about a week. function pause() external { if (msg.sender == owner) { // Timelock can release the community multisig right away paused = 2; } else if (msg.sender == multisig) { // Multisig needs to check if the governor check proposal Id state is defeated ProposalState state = IGovernor(governor).state(governorCheckProposalId); if (state == ProposalState.Defeated) { paused = 2; } else { revert NotDefeated(governorCheckProposalId, state); } } else { // msg.sender is not a timelock, nor a multisig revert ManagerOnly(msg.sender, multisig); } emit GuardPaused(msg.sender); } /// @dev Unpauses the guard restricting the CM functionality back. function unpause() external { // Check for the ownership if (msg.sender != owner) { revert OwnerOnly(msg.sender, owner); } paused = 1; emit GuardUnpaused(); } /// @dev Guards the multisig call after its execution. function checkAfterExecution(bytes32, bool) external {} /// @dev Gets the status of a target-selector-chainId combination. /// @param target Target address. /// @param selector Selector for a target. /// @param chainId Corresponding chain Id. /// @return status True, if the target-selector-chainId combination is authorized. function getTargetSelectorChainId(address target, bytes4 selector, uint256 chainId) external view returns (bool status) { // Push a pair of key defining variables into one key // target occupies first 160 bits uint256 targetSelectorChainId = uint256(uint160(target)); // selector occupies next 32 bits targetSelectorChainId |= uint256(uint32(selector)) << 160; // chainId occupies next 64 bits targetSelectorChainId |= chainId << 192; status = mapAllowedTargetSelectorChainIds[targetSelectorChainId]; } /// @dev Gets the address of a bridge mediator contract address on L2 and corresponding L2 chain Id. /// @param bridgeMediatorL1 Bridge mediator contract addresses on L1. /// @return bridgeMediatorL2 Corresponding bridge mediator contract addresses on L2. /// @return chainId Corresponding L2 chain Ids. function getBridgeMediatorChainId(address bridgeMediatorL1) external view returns (address bridgeMediatorL2, uint256 chainId) { // Get the bridgeMediatorL2 and L2 chain Id uint256 bridgeMediatorL2ChainId = mapBridgeMediatorL1L2ChainIds[bridgeMediatorL1]; // bridgeMediatorL2 occupies first 160 bits bridgeMediatorL2 = address(uint160(bridgeMediatorL2ChainId)); // L2 chain Id occupies next 64 bits chainId = bridgeMediatorL2ChainId >> 160; } }

question:so the contract is not contain any vulnerability

question:how aboyt the issue in The pause function should enforce the check for the defeated proposal state even when the owner is calling the function. This ensures that the guard can only be paused if the governance is considered inactive, maintaining the integrity of the governance process i think its invalid her eis the contract to make sure // SPDX-License-Identifier: MIT pragma solidity ^0.8.23; import {Enum} from "@gnosis.pm/safe-contracts/contracts/common/Enum.sol"; interface IGovernor { function state(uint256 proposalId) external returns (ProposalState); } // Governor proposal state enum ProposalState { Pending, Active, Canceled, Defeated, Succeeded, Queued, Expired, Executed } /// @dev Only `owner` has a privilege, but the `sender` was provided. /// @param sender Sender address. /// @param owner Required sender address as an owner. error OwnerOnly(address sender, address owner); /// @dev Only `manager` has a privilege, but the `sender` was provided. /// @param sender Sender address. /// @param manager Required sender address as an owner. error ManagerOnly(address sender, address manager); /// @dev Provided zero address. error ZeroAddress(); /// @dev Provided zero value. error ZeroValue(); /// @dev Wrong length of two arrays. /// @param numValues1 Number of values in a first array. /// @param numValues2 Numberf of values in a second array. /// @param numValues3 Numberf of values in a third array. /// @param numValues4 Numberf of values in a fourth array. error WrongArrayLength(uint256 numValues1, uint256 numValues2, uint256 numValues3, uint256 numValues4); /// @dev Provided bridged mediator is not unique. /// @param bridgeMediator Bridge mediator address. error BridgeMediatorNotUnique(address bridgeMediator); /// @dev Provided incorrect data length. /// @param expected Expected minimum data length. /// @param provided Provided data length. error IncorrectDataLength(uint256 expected, uint256 provided); /// @dev No delegatecall is allowed. error NoDelegateCall(); /// @dev No self multisig call is allowed. error NoSelfCall(); /// @dev The combination of target and selector is not authorized. /// @param target Target address. /// @param selector Function selector. /// @param chainId Chain Id. error NotAuthorized(address target, bytes4 selector, uint256 chainId); /// @dev The proposal is not defeated. /// @param proposalId Proposal Id. /// @param state Current proposal state. error NotDefeated(uint256 proposalId, ProposalState state); /// @dev Passed L2 chain Id is not supported. /// @param chainId L2 chain Id. error L2ChainIdNotSupported(uint256 chainId); /// @dev Provided wrong function selector. /// @param functionSig Function selector. /// @param chainId Chain Id. error WrongSelector(bytes4 functionSig, uint256 chainId); /// @dev Provided wrong L2 bridge mediator address. /// @param provided Provided address. /// @param expected Expected address. error WrongL2BridgeMediator(address provided, address expected); /// @title GuardCM - Smart contract for Gnosis Safe community multisig (CM) guard /// @author Aleksandr Kuperman - <[email protected]> /// @author Andrey Lebedev - <<PRESIDIO_ANONYMIZED_EMAIL_ADDRESS>> contract GuardCM { event GovernorUpdated(address indexed governor); event SetTargetSelectors(address[] indexed targets, bytes4[] indexed selectors, uint256[] chainIds, bool[] statuses); event SetBridgeMediators(address[] indexed bridgeMediatorL1s, address[] indexed bridgeMediatorL2s, uint256[] chainIds); event GovernorCheckProposalIdChanged(uint256 indexed proposalId); event GuardPaused(address indexed account); event GuardUnpaused(); // schedule selector bytes4 public constant SCHEDULE = bytes4(keccak256(bytes("schedule(address,uint256,bytes,bytes32,bytes32,uint256)"))); // scheduleBatch selector bytes4 public constant SCHEDULE_BATCH = bytes4(keccak256(bytes("scheduleBatch(address[],uint256[],bytes[],bytes32,bytes32,uint256)"))); // requireToPassMessage selector (Gnosis chain) bytes4 public constant REQUIRE_TO_PASS_MESSAGE = bytes4(keccak256(bytes("requireToPassMessage(address,bytes,uint256)"))); // processMessageFromForeign selector (Gnosis chain) bytes4 public constant PROCESS_MESSAGE_FROM_FOREIGN = bytes4(keccak256(bytes("processMessageFromForeign(bytes)"))); // sendMessageToChild selector (Polygon) bytes4 public constant SEND_MESSAGE_TO_CHILD = bytes4(keccak256(bytes("sendMessageToChild(address,bytes)"))); // Initial check governance proposal Id // Calculated from the proposalHash function of the GovernorOLAS uint256 public governorCheckProposalId = 88250008686885504216650933897987879122244685460173810624866685274624741477673; // Minimum data length that is encoded for the schedule function, // plus at least 4 bytes or 32 bits for the selector from the payload uint256 public constant MIN_SCHEDULE_DATA_LENGTH = 260; // Minimum data length that contains at least a selector (4 bytes or 32 bits) uint256 public constant SELECTOR_DATA_LENGTH = 4; // Minimum payload length for message on Gnosis accounting for all required encoding and at least one selector uint256 public constant MIN_GNOSIS_PAYLOAD_LENGTH = 292; // Minimum payload length for message on Polygon accounting for all required encoding and at least one selector uint256 public constant MIN_POLYGON_PAYLOAD_LENGTH = 164; // Owner address address public immutable owner; // Multisig address address public immutable multisig; // Governor address address public governor; // Guard pausing possibility uint8 public paused = 1; // Mapping of (target address | bytes4 selector | uint64 chain Id) => enabled / disabled mapping(uint256 => bool) public mapAllowedTargetSelectorChainIds; // Mapping of bridge mediator address L1 => (bridge mediator L2 address | uint64 supported L2 chain Id) mapping(address => uint256) public mapBridgeMediatorL1L2ChainIds; /// @dev GuardCM constructor. /// @param _timelock Timelock address. /// @param _multisig Community multisig address. /// @param _governor Governor address. constructor( address _timelock, address _multisig, address _governor ) { // Check for zero addresses if (_timelock == address(0) || _multisig == address(0) || _governor == address(0)) { revert ZeroAddress(); } owner = _timelock; multisig = _multisig; governor = _governor; } /// @dev Changes the governor. /// @param newGovernor Address of a new governor. function changeGovernor(address newGovernor) external { if (msg.sender != owner) { revert OwnerOnly(msg.sender, owner); } // Check for the zero address if (newGovernor == address(0)) { revert ZeroAddress(); } governor = newGovernor; emit GovernorUpdated(newGovernor); } /// @dev Changes the governor check proposal Id. /// @param proposalId Governor check proposal Id. function changeGovernorCheckProposalId(uint256 proposalId) external { if (msg.sender != owner) { revert OwnerOnly(msg.sender, owner); } // Check for the zero value if (proposalId == 0) { revert ZeroValue(); } governorCheckProposalId = proposalId; emit GovernorCheckProposalIdChanged(proposalId); } /// @dev Verifies authorized combinations of target and selector. /// @notice The bottom-most internal function is still not "view" since some reverts are not explicitly handled /// @param target Target address. /// @param data Payload bytes. /// @param chainId Chain Id. function _verifyData(address target, bytes memory data, uint256 chainId) internal { // Push a pair of key defining variables into one key // target occupies first 160 bits uint256 targetSelectorChainId = uint256(uint160(target)); // selector occupies next 32 bits targetSelectorChainId |= uint256(uint32(bytes4(data))) << 160; // chainId occupies next 64 bits targetSelectorChainId |= chainId << 192; // Check the authorized combination of target and selector if (!mapAllowedTargetSelectorChainIds[targetSelectorChainId]) { revert NotAuthorized(target, bytes4(data), chainId); } } /// @dev Verifies the bridged data for authorized combinations of targets and selectors. /// @notice The processed data is packed as a set of bytes that are assembled using the following parameters: /// address target, uint96 value, uint32 payloadLength, bytes payload. /// @param data Payload bytes. /// @param chainId L2 chain Id. function _verifyBridgedData(bytes memory data, uint256 chainId) internal { // Unpack and process the data // We need to skip first 12 bytes as those are zeros from encoding for (uint256 i = 0; i < data.length;) { address target; uint32 payloadLength; // solhint-disable-next-line no-inline-assembly assembly { // First 20 bytes is the address (160 bits) i := add(i, 20) target := mload(add(data, i)) // Offset the data by 12 bytes of value (96 bits) and by 4 bytes of payload length (32 bits) i := add(i, 16) payloadLength := mload(add(data, i)) } // Check for the zero address if (target == address(0)) { revert ZeroAddress(); } // The payload length must be at least of the a function selector size if (payloadLength < SELECTOR_DATA_LENGTH) { revert IncorrectDataLength(payloadLength, SELECTOR_DATA_LENGTH); } // Get the payload bytes memory payload = new bytes(payloadLength); for (uint256 j = 0; j < payloadLength; ++j) { payload[j] = data[i + j]; } // Offset the data by the payload number of bytes i += payloadLength; // Verify the scope of the data _verifyData(target, payload, chainId); } } /// @dev Processes bridged data: checks the header and verifies the payload. /// @param data Full data bytes with the header. /// @param bridgeMediatorL2 Address of a bridged mediator on L2. /// @param chainId L2 chain Id. function _processBridgeData( bytes memory data, address bridgeMediatorL2, uint256 chainId ) internal { // Gnosis chains if (chainId == 100 || chainId == 10200) { // Check the L1 initial selector bytes4 functionSig = bytes4(data); if (functionSig != REQUIRE_TO_PASS_MESSAGE) { revert WrongSelector(functionSig, chainId); } // Check if the data length is less than a size of a selector plus the message minimum payload size if (data.length < MIN_GNOSIS_PAYLOAD_LENGTH) { revert IncorrectDataLength(data.length, MIN_GNOSIS_PAYLOAD_LENGTH); } // Copy the data without the selector bytes memory payload = new bytes(data.length - SELECTOR_DATA_LENGTH); for (uint256 i = 0; i < payload.length; ++i) { payload[i] = data[i + 4]; } // Decode the requireToPassMessage payload: homeMediator (L2), mediatorPayload (need decoding), requestGasLimit (address homeMediator, bytes memory mediatorPayload, ) = abi.decode(payload, (address, bytes, uint256)); // Check that the home mediator matches the L2 bridge mediator address if (homeMediator != bridgeMediatorL2) { revert WrongL2BridgeMediator(homeMediator, bridgeMediatorL2); } // Check the L2 initial selector functionSig = bytes4(mediatorPayload); if (functionSig != PROCESS_MESSAGE_FROM_FOREIGN) { revert WrongSelector(functionSig, chainId); } // Copy the data without a selector bytes memory bridgePayload = new bytes(mediatorPayload.length - SELECTOR_DATA_LENGTH); for (uint256 i = 0; i < bridgePayload.length; ++i) { bridgePayload[i] = mediatorPayload[i + SELECTOR_DATA_LENGTH]; } // Decode the processMessageFromForeign payload: l2Message (executed on L2) (bytes memory l2Message) = abi.decode(bridgePayload, (bytes)); // Verify processMessageFromForeign payload _verifyBridgedData(l2Message, chainId); } // Polygon chains if (chainId == 137 || chainId == 80001) { // Check the L1 initial selector bytes4 functionSig = bytes4(data); if (functionSig != SEND_MESSAGE_TO_CHILD) { revert WrongSelector(functionSig, chainId); } // Check if the data length is less than a size of a selector plus the message minimum payload size if (data.length < MIN_POLYGON_PAYLOAD_LENGTH) { revert IncorrectDataLength(data.length, MIN_POLYGON_PAYLOAD_LENGTH); } // Copy the data without the selector bytes memory payload = new bytes(data.length - SELECTOR_DATA_LENGTH); for (uint256 i = 0; i < payload.length; ++i) { payload[i] = data[i + SELECTOR_DATA_LENGTH]; } // Decode sendMessageToChild payload: fxGovernorTunnel (L2), l2Message (executed on L2) (address fxGovernorTunnel, bytes memory l2Message) = abi.decode(payload, (address, bytes)); // Check that the fxGovernorTunnel matches the L2 bridge mediator address if (fxGovernorTunnel != bridgeMediatorL2) { revert WrongL2BridgeMediator(fxGovernorTunnel, bridgeMediatorL2); } // Verify sendMessageToChild payload _verifyBridgedData(l2Message, chainId); } } /// @dev Verifies authorized target and selector in the schedule or scheduleBatch function call. /// @param data Data in bytes. /// @param selector Schedule function selector. function _verifySchedule(bytes memory data, bytes4 selector) internal { // Copy the data without the selector bytes memory payload = new bytes(data.length - SELECTOR_DATA_LENGTH); for (uint256 i = 0; i < payload.length; ++i) { payload[i] = data[i + 4]; } // Prepare the decoding data sets address[] memory targets; bytes[] memory callDatas; if (selector == SCHEDULE) { targets = new address[](1); callDatas = new bytes[](1); // Decode the data in the schedule function (targets[0], , callDatas[0], , , ) = abi.decode(payload, (address, uint256, bytes, bytes32, bytes32, uint256)); } else { // Decode the data in the scheduleBatch function (targets, , callDatas, , , ) = abi.decode(payload, (address[], uint256[], bytes[], bytes32, bytes32, uint256)); } // Traverse all the schedule targets and selectors extracted from calldatas for (uint i = 0; i < targets.length; ++i) { // Get the bridgeMediatorL2 and L2 chain Id, if any uint256 bridgeMediatorL2ChainId = mapBridgeMediatorL1L2ChainIds[targets[i]]; // bridgeMediatorL2 occupies first 160 bits address bridgeMediatorL2 = address(uint160(bridgeMediatorL2ChainId)); // Check if the data goes across the bridge if (bridgeMediatorL2 != address(0)) { // Get the chain Id // L2 chain Id occupies next 64 bits uint256 chainId = bridgeMediatorL2ChainId >> 160; // Process the bridge logic _processBridgeData(callDatas[i], bridgeMediatorL2, chainId); } else { // Verify the data right away as it is not the bridged one _verifyData(targets[i], callDatas[i], block.chainid); } } } /// @dev Checks the transaction for authorized arguments. /// @notice Scheduling in timelock is checked against authorized targets and signatures. /// @notice No self-multisig function calls are allowed. /// @param to Destination address of Safe transaction. /// @param data Data payload of Safe transaction. /// @param operation Operation type of Safe transaction. function checkTransaction( address to, uint256, bytes memory data, Enum.Operation operation, uint256, uint256, uint256, address, address payable, bytes memory, address ) external { // Just return if paused if (paused == 1) { // Call to the timelock if (to == owner) { // No delegatecall is allowed if (operation == Enum.Operation.DelegateCall) { revert NoDelegateCall(); } // Data needs to have enough bytes at least to fit the selector if (data.length < SELECTOR_DATA_LENGTH) { revert IncorrectDataLength(data.length, SELECTOR_DATA_LENGTH); } // Get the function signature bytes4 functionSig = bytes4(data); // Check the schedule or scheduleBatch function authorized parameters // All other functions are not checked for if (functionSig == SCHEDULE || functionSig == SCHEDULE_BATCH) { // Data length is too short: need to have enough bytes for the schedule() function // with one selector extracted from the payload if (data.length < MIN_SCHEDULE_DATA_LENGTH) { revert IncorrectDataLength(data.length, MIN_SCHEDULE_DATA_LENGTH); } _verifySchedule(data, functionSig); } } else if (to == multisig) { // No self multisig call is allowed revert NoSelfCall(); } } } /// @dev Authorizes combinations of targets, selectors and chain Ids. /// @notice It is the contract owner responsibility to set correct L1 chain Ids where the contract is deployed /// and corresponding supported L2-s, if the contract interacts with them. /// @param targets Array of target addresses. /// @param selectors Array of selectors for targets. /// @param chainIds Chain Ids for authorized functions. /// @param statuses Authorize if true, and restrict otherwise. function setTargetSelectorChainIds( address[] memory targets, bytes4[] memory selectors, uint256[] memory chainIds, bool[] memory statuses ) external { // Check for the ownership if (msg.sender != owner) { revert OwnerOnly(msg.sender, owner); } // Check array length if (targets.length != selectors.length || targets.length != statuses.length || targets.length != chainIds.length) { revert WrongArrayLength(targets.length, selectors.length, statuses.length, chainIds.length); } // Traverse all the targets and selectors to build their paired values for (uint256 i = 0; i < targets.length; ++i) { // Check for zero address targets if (targets[i] == address(0)) { revert ZeroAddress(); } // Check selector for zero selector value if (selectors[i] == bytes4(0)) { revert ZeroValue(); } // Check chain Ids to be greater than zero if (chainIds[i] == 0) { revert ZeroValue(); } // Push a pair of key defining variables into one key // target occupies first 160 bits uint256 targetSelectorChainId = uint256(uint160(targets[i])); // selector occupies next 32 bits targetSelectorChainId |= uint256(uint32(selectors[i])) << 160; // chainId occupies next 64 bits targetSelectorChainId |= chainIds[i] << 192; // Set the status of the target and selector combination mapAllowedTargetSelectorChainIds[targetSelectorChainId] = statuses[i]; } emit SetTargetSelectors(targets, selectors, chainIds, statuses); } /// @dev Sets bridge mediator contracts addresses and L2 chain Ids. /// @notice It is the contract owner responsibility to set correct L1 bridge mediator contracts, /// corresponding L2 bridge mediator contracts, and supported chain Ids. /// @param bridgeMediatorL1s Bridge mediator contract addresses on L1. /// @param bridgeMediatorL2s Corresponding bridge mediator contract addresses on L2. /// @param chainIds Corresponding L2 chain Ids. function setBridgeMediatorChainIds( address[] memory bridgeMediatorL1s, address[] memory bridgeMediatorL2s, uint256[] memory chainIds ) external { // Check for the ownership if (msg.sender != owner) { revert OwnerOnly(msg.sender, owner); } // Check for array correctness if (bridgeMediatorL1s.length != bridgeMediatorL2s.length || bridgeMediatorL1s.length != chainIds.length) { revert WrongArrayLength(bridgeMediatorL1s.length, bridgeMediatorL2s.length, chainIds.length, chainIds.length); } // Link L1 and L2 bridge mediators, set L2 chain Ids for (uint256 i = 0; i < chainIds.length; ++i) { // Check for zero addresses if (bridgeMediatorL1s[i] == address(0) || bridgeMediatorL2s[i] == address(0)) { revert ZeroAddress(); } // Check supported chain Ids on L2 uint256 chainId = chainIds[i]; if (chainId != 100 && chainId != 137 && chainId != 10200 && chainId != 80001) { revert L2ChainIdNotSupported(chainId); } // Push a pair of key defining variables into one key // bridgeMediatorL2 occupies first 160 bits uint256 bridgeMediatorL2ChainId = uint256(uint160(bridgeMediatorL2s[i])); // L2 chain Id occupies next 64 bits bridgeMediatorL2ChainId |= chainId << 160; mapBridgeMediatorL1L2ChainIds[bridgeMediatorL1s[i]] = bridgeMediatorL2ChainId; } emit SetBridgeMediators(bridgeMediatorL1s, bridgeMediatorL2s, chainIds); } /// @dev Pauses the guard restoring a full CM functionality. /// @notice The timeline is able to pause the guard via the voting. /// @notice The CM can request pausing the guard is there was a proposal to check if the governance is alive. /// If the proposal is defeated (not enough votes or never voted on), /// the governance is considered inactive for about a week. function pause() external { if (msg.sender == owner) { // Timelock can release the community multisig right away paused = 2; } else if (msg.sender == multisig) { // Multisig needs to check if the governor check proposal Id state is defeated ProposalState state = IGovernor(governor).state(governorCheckProposalId); if (state == ProposalState.Defeated) { paused = 2; } else { revert NotDefeated(governorCheckProposalId, state); } } else { // msg.sender is not a timelock, nor a multisig revert ManagerOnly(msg.sender, multisig); } emit GuardPaused(msg.sender); } /// @dev Unpauses the guard restricting the CM functionality back. function unpause() external { // Check for the ownership if (msg.sender != owner) { revert OwnerOnly(msg.sender, owner); } paused = 1; emit GuardUnpaused(); } /// @dev Guards the multisig call after its execution. function checkAfterExecution(bytes32, bool) external {} /// @dev Gets the status of a target-selector-chainId combination. /// @param target Target address. /// @param selector Selector for a target. /// @param chainId Corresponding chain Id. /// @return status True, if the target-selector-chainId combination is authorized. function getTargetSelectorChainId(address target, bytes4 selector, uint256 chainId) external view returns (bool status) { // Push a pair of key defining variables into one key // target occupies first 160 bits uint256 targetSelectorChainId = uint256(uint160(target)); // selector occupies next 32 bits targetSelectorChainId |= uint256(uint32(selector)) << 160; // chainId occupies next 64 bits targetSelectorChainId |= chainId << 192; status = mapAllowedTargetSelectorChainIds[targetSelectorChainId]; } /// @dev Gets the address of a bridge mediator contract address on L2 and corresponding L2 chain Id. /// @param bridgeMediatorL1 Bridge mediator contract addresses on L1. /// @return bridgeMediatorL2 Corresponding bridge mediator contract addresses on L2. /// @return chainId Corresponding L2 chain Ids. function getBridgeMediatorChainId(address bridgeMediatorL1) external view returns (address bridgeMediatorL2, uint256 chainId) { // Get the bridgeMediatorL2 and L2 chain Id uint256 bridgeMediatorL2ChainId = mapBridgeMediatorL1L2ChainIds[bridgeMediatorL1]; // bridgeMediatorL2 occupies first 160 bits bridgeMediatorL2 = address(uint160(bridgeMediatorL2ChainId)); // L2 chain Id occupies next 64 bits chainId = bridgeMediatorL2ChainId >> 160; } }

question:so this is invalid ok move to the issue in the setBridgeMediatorChainIds function should include a check to ensure that each L1 bridge mediator is mapped to a unique L2 bridge mediator and chain ID combination. This prevents potential conflicts or errors in bridge mediator mappings review the ccontract and see if it's valid and correct or invalid with evidence