feat!: Add gas limits to queries (backport #16239) (#17324)

Co-authored-by: Dev Ojha <ValarDragon@users.noreply.github.com>

baseapp/abci.go

@@ -1116,7 +1116,8 @@ func (app *BaseApp) CreateQueryContext(height int64, prove bool) (sdk.Context, e
 	// branch the commit multi-store for safety
 	ctx := sdk.NewContext(cacheMS, app.checkState.ctx.BlockHeader(), true, app.logger).
 		WithMinGasPrices(app.minGasPrices).
-		WithBlockHeight(height)
+		WithBlockHeight(height).
+		WithGasMeter(storetypes.NewGasMeter(app.queryGasLimit))
 
 	if height != lastBlockHeight {
 		rms, ok := app.cms.(*rootmulti.Store)

baseapp/baseapp.go

@@ -3,6 +3,7 @@ package baseapp
 import (
 	"context"
 	"fmt"
+	"math"
 	"sort"
 	"strconv"
 
@@ -123,6 +124,9 @@ type BaseApp struct {
 	// application parameter store.
 	paramStore ParamStore
 
+	// queryGasLimit defines the maximum gas for queries; unbounded if 0.
+	queryGasLimit uint64
+
 	// The minimum gas prices a validator is willing to accept for processing a
 	// transaction. This is mainly used for DoS and spam prevention.
 	minGasPrices sdk.DecCoins
@@ -192,6 +196,7 @@ func NewBaseApp(
 		msgServiceRouter: NewMsgServiceRouter(),
 		txDecoder:        txDecoder,
 		fauxMerkleMode:   false,
+		queryGasLimit:    math.MaxUint64,
 	}
 
 	for _, option := range options {

baseapp/baseapp_test.go

@@ -85,6 +85,26 @@ func NewBaseAppSuite(t *testing.T, opts ...func(*baseapp.BaseApp)) *BaseAppSuite
 	}
 }
 
+func getQueryBaseapp(t *testing.T) *baseapp.BaseApp {
+	t.Helper()
+
+	db := dbm.NewMemDB()
+	name := t.Name()
+	app := baseapp.NewBaseApp(name, log.NewTestLogger(t), db, nil)
+
+	_, err := app.FinalizeBlock(&abci.RequestFinalizeBlock{Height: 1})
+	require.NoError(t, err)
+	_, err = app.Commit()
+	require.NoError(t, err)
+
+	_, err = app.FinalizeBlock(&abci.RequestFinalizeBlock{Height: 2})
+	require.NoError(t, err)
+	_, err = app.Commit()
+	require.NoError(t, err)
+
+	return app
+}
+
 func NewBaseAppSuiteWithSnapshots(t *testing.T, cfg SnapshotsConfig, opts ...func(*baseapp.BaseApp)) *BaseAppSuite {
 	snapshotTimeout := 1 * time.Minute
 	snapshotStore, err := snapshots.NewStore(dbm.NewMemDB(), testutil.GetTempDir(t))
@@ -614,6 +634,60 @@ func TestSetMinGasPrices(t *testing.T) {
 	require.Equal(t, minGasPrices, ctx.MinGasPrices())
 }
 
+type ctxType string
+
+const (
+	QueryCtx   ctxType = "query"
+	CheckTxCtx ctxType = "checkTx"
+)
+
+var ctxTypes = []ctxType{QueryCtx, CheckTxCtx}
+
+func (c ctxType) GetCtx(t *testing.T, bapp *baseapp.BaseApp) sdk.Context {
+	t.Helper()
+	if c == QueryCtx {
+		ctx, err := bapp.CreateQueryContext(1, false)
+		require.NoError(t, err)
+		return ctx
+	} else if c == CheckTxCtx {
+		return getCheckStateCtx(bapp)
+	}
+	// TODO: Not supported yet
+	return getFinalizeBlockStateCtx(bapp)
+}
+
+func TestQueryGasLimit(t *testing.T) {
+	testCases := []struct {
+		queryGasLimit   uint64
+		gasActuallyUsed uint64
+		shouldQueryErr  bool
+	}{
+		{queryGasLimit: 100, gasActuallyUsed: 50, shouldQueryErr: false},  // Valid case
+		{queryGasLimit: 100, gasActuallyUsed: 150, shouldQueryErr: true},  // gasActuallyUsed > queryGasLimit
+		{queryGasLimit: 0, gasActuallyUsed: 50, shouldQueryErr: false},    // fuzzing with queryGasLimit = 0
+		{queryGasLimit: 0, gasActuallyUsed: 0, shouldQueryErr: false},     // both queryGasLimit and gasActuallyUsed are 0
+		{queryGasLimit: 200, gasActuallyUsed: 200, shouldQueryErr: false}, // gasActuallyUsed == queryGasLimit
+		{queryGasLimit: 100, gasActuallyUsed: 1000, shouldQueryErr: true}, // gasActuallyUsed > queryGasLimit
+	}
+
+	for _, tc := range testCases {
+		for _, ctxType := range ctxTypes {
+			t.Run(fmt.Sprintf("%s: %d - %d", ctxType, tc.queryGasLimit, tc.gasActuallyUsed), func(t *testing.T) {
+				app := getQueryBaseapp(t)
+				baseapp.SetQueryGasLimit(tc.queryGasLimit)(app)
+				ctx := ctxType.GetCtx(t, app)
+
+				// query gas limit should have no effect when CtxType != QueryCtx
+				if tc.shouldQueryErr && ctxType == QueryCtx {
+					require.Panics(t, func() { ctx.GasMeter().ConsumeGas(tc.gasActuallyUsed, "test") })
+				} else {
+					require.NotPanics(t, func() { ctx.GasMeter().ConsumeGas(tc.gasActuallyUsed, "test") })
+				}
+			})
+		}
+	}
+}
+
 func TestGetMaximumBlockGas(t *testing.T) {
 	suite := NewBaseAppSuite(t)
 	_, err := suite.baseApp.InitChain(&abci.RequestInitChain{})

baseapp/options.go

@@ -3,6 +3,7 @@ package baseapp
 import (
 	"fmt"
 	"io"
+	"math"
 
 	dbm "github.com/cosmos/cosmos-db"
 
@@ -36,6 +37,15 @@ func SetMinGasPrices(gasPricesStr string) func(*BaseApp) {
 	return func(bapp *BaseApp) { bapp.setMinGasPrices(gasPrices) }
 }
 
+// SetQueryGasLimit returns an option that sets a gas limit for queries.
+func SetQueryGasLimit(queryGasLimit uint64) func(*BaseApp) {
+	if queryGasLimit == 0 {
+		queryGasLimit = math.MaxUint64
+	}
+
+	return func(bapp *BaseApp) { bapp.queryGasLimit = queryGasLimit }
+}
+
 // SetHaltHeight returns a BaseApp option function that sets the halt block height.
 func SetHaltHeight(blockHeight uint64) func(*BaseApp) {
 	return func(bapp *BaseApp) { bapp.setHaltHeight(blockHeight) }