Liquidity Management

Summary

The PerpetualVault contract employs a _gmxLock state variable to lock the contract during GMX-related asynchronous operations. This prevents reentrant actions while awaiting GMX order execution callbacks. However, if an unexpected issue arises (e.g., a callback is never received or the GMX system fails), _gmxLock can become permanently stuck in the true state. This would effectively freeze all vault operations, preventing deposits, withdrawals, or position adjustments.

Vulnerability Details

Affected Code:

The _gmxLock is set to true during operations involving GMX and is only reset to false upon receiving a successful callback:

If the callback is never received or processing fails, _gmxLock remains true indefinitely.

Key Risks:

• Permanent Vault Freeze: Users would be unable to deposit, withdraw, or adjust positions.

• Loss of Operational Control: Even privileged roles (e.g., owner, keeper) cannot override _gmxLock once set to true.

• Multiple Reset Points: Although _gmxLock is set to false in multiple callback handlers, any missed or failed callback can still lead to a permanent lockup. Furthermore, setting _gmxLock = false in multiple places does not fully mitigate the risk, as any of these callbacks can revert, leaving _gmxLock stuck as true.

Impact

• High Impact: Vault funds become inaccessible, and user operations halt indefinitely.

• Likelihood: Moderate. While GMX failures or callback issues are rare, they are not impossible. External dependencies can always introduce unpredictable results so reverting callbacks are possible and prevention should be attempted.

Tools Used

Manual Code Review

Recommendations

Introduce an emergency unlock function to allow the owner to reset _gmxLock in case of failure:

This function should be used only in rare, emergency cases. Adding an event provides transparency when it is invoked.

Rationale

An emergency mechanism prevents operational lockup without compromising normal contract security. As only the owner can invoke this function, the risk is minimal compared to the consequence of a frozen vault.