Unsubscription Missing at `filter` Api With Subscription Error

[CertiK-Geth]

System information

Geth version: v1.16.4
OS & Version: OSX
Commit hash : 2037c53
Location:

• https://github.com/ethereum/go-ethereum/blob/master/eth/filters/api.go#L151-L155

Expected behaviour

The filter creation function NewPendingTransactionFilter creates PendingTransactionFilter with subscription, when error occurs, it should remove the subsription as cleanup.

Actual behaviour

The filter creation function NewPendingTransactionFilter exhibit resource leaks by failing to properly unsubscribe from event subscriptions when errors occur. While the existing timeout mechanism provides eventual cleanup, this represents a suboptimal resource management pattern that could lead to gradual performance degradation in long-running services.