context.DeadlineExceeded misclassified as ErrPortClosedOrFiltered, poisoning dial cache #530
Description
Bug
dialAllParallel in dialwrap.go treats context.DeadlineExceeded as a permanent error and wraps it as ErrPortClosedOrFiltered. This poisons the shared dial cache — every subsequent connection to that host:port fails immediately for the rest of the scan, even with a fresh context.
The same gap exists for context.Canceled at the final error-classification point, and in DialContext where a deadline-exceeded first connection is returned as a permanent failure instead of being retried.
Impact
Under load, timed-out dial attempts silently block all future connections to affected hosts across all protocol types for the remainder of the scan. This is exacerbated by the JS VM pool starvation bug in nuclei (projectdiscovery/nuclei#6865), which feeds expired contexts into the dialer.
Fix
PR: #529