HAL-06 iteration over map source of non-determinism #3257
Description
Description
The codebase contains instances of iteration over maps. As maps are not ordered in Go, iterations over maps are non-deterministic. If the consensus logic expects a deterministic result from the iteration, errors can occur where different nodes reach different states due to the differences in map ordering. If the nodes reach differing states, this can cause consensus issues, which could result in a chain halt.
Code Location:
x/tokenregistry/types/types.pb.go, Lines 582-601
Listing 8: Iteration over map (Line 582)
582 for k := range m. DoublePeggedNetworkMap {
583 v := m. DoublePeggedNetworkMap [k]
584 baseI := i
585 i- -
586 if v {
587 dAtA [i] = 1
588 } else {
589 dAtA [i] = 0
590 }
591 i- -
592 dAtA [i] = 0 x10
593 i = encodeVarintTypes (dAtA , i, uint64 (k))
594 i- -
595 dAtA [i] = 0x8
596 i = encodeVarintTypes (dAtA , i, uint64 (baseI -i))
597 i- -
598 dAtA [i] = 0x1
599 i- -
600 dAtA [i] = 0 x9a
601 }
Recommendation
Ensure that iterations over maps do not contain any logic that depends on a fixed ordering of the map. Alternatively, make use of an alternative data structure that has a deterministic ordering or ensure that maps are sorted before iterating over them.