Causing all events in `wasm.sudo` execution to be lost Due to Forgetting to Pass the `Event` in `subctx` to the Upper Layer

[Hellobloc]

Introduction

Note that the following hook is used in the bank module to execute the wasm contract logic in the bank module, and you already handle the passing of the gasmeter in ctx.

https://github.com/osmosis-labs/cosmos-sdk/blob/5b4e03484cf88e7d1fce003ba75b4fdc5c81f15f/x/bank/types/hooks.go#L18

But you forgot to pass events, which caused all events in the hook execution to be lost, which could eventually lead to inconsistencies between your project's key events and actual state changes.

osmosis/x/tokenfactory/keeper/before_send.go

Lines 119 to 186 in 7f94e29

	func (k Keeper) callBeforeSendListener(context context.Context, from, to sdk.AccAddress, amount sdk.Coins, blockBeforeSend bool) (err error) {
	defer func() {
	if r := recover(); r != nil {
	err = errorsmod.Wrapf(types.ErrBeforeSendHookOutOfGas, "%v", r)
	}
	}()
	ctx := sdk.UnwrapSDKContext(context)
	for _, coin := range amount {
	cosmwasmAddress := k.GetBeforeSendHook(ctx, coin.Denom)
	if cosmwasmAddress != "" {
	cwAddr, err := sdk.AccAddressFromBech32(cosmwasmAddress)
	if err != nil {
	return err
	}
	var msgBz []byte
	// get msgBz, either BlockBeforeSend or TrackBeforeSend
	// Note that for trackBeforeSend, we need to gas meter computations to prevent infinite loop
	// specifically because module to module sends are not gas metered.
	// We don't need to do this for blockBeforeSend since blockBeforeSend is not called during module to module sends.
	if blockBeforeSend {
	msg := types.BlockBeforeSendSudoMsg{
	BlockBeforeSend: types.BlockBeforeSendMsg{
	From: from.String(),
	To: to.String(),
	Amount: osmoutils.CWCoinFromSDKCoin(coin),
	},
	}
	msgBz, err = json.Marshal(msg)
	} else {
	msg := types.TrackBeforeSendSudoMsg{
	TrackBeforeSend: types.TrackBeforeSendMsg{
	From: from.String(),
	To: to.String(),
	Amount: osmoutils.CWCoinFromSDKCoin(coin),
	},
	}
	msgBz, err = json.Marshal(msg)
	}
	if err != nil {
	return err
	}
	em := sdk.NewEventManager()
	// Check remaining gas in parent context and use the lesser of the fixed limit and remaining gas
	gasLimit := min(ctx.GasMeter().GasRemaining(), types.BeforeSendHookGasLimit)
	childCtx := ctx.WithGasMeter(storetypes.NewGasMeter(gasLimit))
	_, err = k.contractKeeper.Sudo(childCtx.WithEventManager(em), cwAddr, msgBz)
	if err != nil {
	if strings.Contains(err.Error(), "no such contract") {
	return nil
	}
	if k.IsModuleAcc(ctx, from) {
	return nil
	}
	return errorsmod.Wrapf(err, "failed to call before send hook for denom %s", coin.Denom)
	}
	// consume gas used for calling contract to the parent ctx
	ctx.GasMeter().ConsumeGas(childCtx.GasMeter().GasConsumed(), "track before send gas")
	}
	}
	return nil
	}

Fix Suggest：

Considering that wasm.sudo as a virtual machine can cause arbitrary target events, we recommend supplementing the event delivery mechanism in a timely manner.

em := sdk.NewEventManager() 
    ...
 	 _, err = k.contractKeeper.Sudo(childCtx.WithEventManager(em), cwAddr, msgBz) 
 	...
    [+]ctx.EventManager().EmitEvents(em.Events())
 	// consume gas used for calling contract to the parent ctx 
 	ctx.GasMeter().ConsumeGas(childCtx.GasMeter().GasConsumed(), "track before send gas") 
 		} 
 	}