Core Contracts

Summary

The batch scheduling system contains critical flaws in handling operation dependencies. The scheduleBatch function allows scheduling operations with unexecuted predecessors, while executeBatch lacks proper execution order validation, potentially leading to permanently stuck operations and execution failures.

Vulnerability Details

1. scheduleBatch Predecessor Handling:

   • Allows dependencies on unexecuted predecessors

   • Creates risk of permanently blocked operations if predecessors fail

2. executeBatch Timing Issues:

   • Lacks validation of operation scheduling relative to predecessor execution

   • May allow incorrect operation ordering leading to execution failures

Impact

• Operations can become permanently unexecutable

• Unclear execution sequencing

• Late detection of scheduling conflicts

Tools Used

• Manual code review

• Foundry testing

• Static analysis (Slither, Mythril)

Recommendations

1. Enhance Predecessor Validation:

   if (predecessor != bytes32(0)) {

   if (!isOperationDone(predecessor)) {

   revert PredecessorNotExecuted(predecessor);

   }

   }

2. Improve Execution Order Checks:

   if (predecessor != bytes32(0)) {

   if (!isOperationDone(predecessor) || _operations[predecessor].timestamp > op.timestamp) {

   revert InvalidExecutionOrder(predecessor);

   }

   }

3. Add Recovery Mechanisms:

   • Implement admin override capability

   • Add automatic cancellation for unreachable operations