add memo length validation

modules/apps/27-interchain-accounts/types/packet.go

@@ -6,12 +6,18 @@ import (
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 )
 
+const MaxMemoCharLength = 256
+
 // ValidateBasic performs basic validation of the interchain account packet data.
 // The memo may be empty.
 func (iapd InterchainAccountPacketData) ValidateBasic() error {
 	if iapd.Data == nil {
 		return sdkerrors.Wrap(ErrInvalidOutgoingData, "packet data cannot be empty")
 	}
+
+	if len(iapd.Memo) > MaxMemoCharLength {
+		return sdkerrors.Wrapf(ErrInvalidOutgoingData, "packet data memo cannot be greater than %d characters", MaxMemoCharLength)
+	}
 	// TODO: add type validation when data type enum supports unspecified type
 
 	return nil

modules/apps/27-interchain-accounts/types/packet_test.go

@@ -4,6 +4,8 @@ import (
 	"github.com/cosmos/ibc-go/v2/modules/apps/27-interchain-accounts/types"
 )
 
+var largeMemo = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum"
+
 func (suite *TypesTestSuite) TestValidateBasic() {
 	testCases := []struct {
 		name       string
@@ -36,6 +38,15 @@ func (suite *TypesTestSuite) TestValidateBasic() {
 			},
 			false,
 		},
+		{
+			"memo too large",
+			types.InterchainAccountPacketData{
+				Type: types.EXECUTE_TX,
+				Data: []byte("data"),
+				Memo: largeMemo,
+			},
+			false,
+		},
 	}
 
 	for _, tc := range testCases {