GHSA-MJFQ-3QR2-6G84

In x/evm/statedb.go:

Add the following function:

func (s *StateDB) RevertMultiStore(cms storetypes.CacheMultiStore, events sdk.Events) {
	s.cacheCtx = s.cacheCtx.WithMultiStore(cms)
	s.writeCache = func() {
		// rollback the events to the ones
		// on the snapshot
		s.ctx.EventManager().EmitEvents(events)
		cms.Write()
	}
}

In x/evm/statedb/journal.go:

Replace the Revert function with the following:

func (pc precompileCallChange) Revert(s *StateDB) {
	// rollback multi store from cache ctx to the previous
	// state stored in the snapshot
	s.RevertMultiStore(pc.multiStore, pc.events)
}

In precompiles/common/precompile.go:

Change the function signature in HandleGasError to:

func HandleGasError(ctx sdk.Context, contract *vm.Contract, initialGas storetypes.Gas, err *error, stateDB *statedb.StateDB, snapshot snapshot) func() {
...
}

In the HandleGasError function, add the following line in the switch statement in the case storetypes.ErrorOutOfGas: case:

stateDB.RevertMultiStore(snapshot.MultiStore, snapshot.Events)

Add the following function:

// RunAtomic is used within the Run function of each Precompile implementation.
// It handles rolling back to the provided snapshot if an error is returned from the core precompile logic.
// Note: This is only required for stateful precompiles.
func (p Precompile) RunAtomic(s snapshot, stateDB *statedb.StateDB, fn func() ([]byte, error)) ([]byte, error) {
	bz, err := fn()
	if err != nil {
		// revert to snapshot on error
		stateDB.RevertMultiStore(s.MultiStore, s.Events)
	}
	return bz, err
}

All Precompiles:

Finally, in each precompile, locate the Run function, and wrap each switch statement and return values into p.RunAtomic. For example:

// Run executes the precompiled contract IBC transfer methods defined in the ABI.
func (p Precompile) Run(evm *vm.EVM, contract *vm.Contract, readOnly bool) (bz []byte, err error) {
	ctx, stateDB, snapshot, method, initialGas, args, err := p.RunSetup(evm, contract, readOnly, p.IsTransaction)
	if err != nil {
		return nil, err
	}

	// This handles any out of gas errors that may occur during the execution of a precompile tx or query.
	// It avoids panics and returns the out of gas error so the EVM can continue gracefully.
	defer cmn.HandleGasError(ctx, contract, initialGas, &err, stateDB, snapshot)()

        // === WRAP HERE ===
	return p.RunAtomic(snapshot, stateDB, func() ([]byte, error) {
		switch method.Name {
		// TODO Approval transactions => need cosmos-sdk v0.46 & ibc-go v6.2.0
		// Authorization Methods:
		case exampleCase:
			bz, err = p.example(ctx, evm.Origin, stateDB, method, args)
		default:
			return nil, fmt.Errorf(cmn.ErrUnknownMethod, method.Name)
		}

		if err != nil {
			return nil, err
		}

		cost := ctx.GasMeter().GasConsumed() - initialGas

		if !contract.UseGas(cost) {
			return nil, vm.ErrOutOfGas
		}

		if err := p.AddJournalEntries(stateDB, snapshot); err != nil {
			return nil, err
		}

		return bz, nil
	})
}

Workarounds

There are no workarounds for chains that make use of precompiles. A coordinated upgrade is necessary to patch the issue.

Testing

A test was introduced in the distribution precompile to ensure that partial state writes no longer occur when a lower gas amount is set.