fix(baseapp): fix BaseApp.getContext data races

This change adds a mutex to BaseApp and firstly locks it
when invoking (*BaseApp).getContextForTx. Ideally the (types/sdk).Context
should be concurrency safe mirroring the Go standard library's
context.Context.

Fixes #18382

baseapp/baseapp.go

@@ -6,6 +6,7 @@ import (
 	"math"
 	"sort"
 	"strconv"
+	"sync"
 
 	"github.com/cockroachdb/errors"
 	abci "github.com/cometbft/cometbft/abci/types"
@@ -59,6 +60,7 @@ var _ servertypes.ABCI = (*BaseApp)(nil)
 // BaseApp reflects the ABCI application implementation.
 type BaseApp struct {
 	// initialized on creation
+	mu                sync.Mutex // mu protects the fields below.
 	logger            log.Logger
 	name              string                      // application name from abci.BlockInfo
 	db                dbm.DB                      // common DB backend
@@ -641,6 +643,9 @@ func (app *BaseApp) getBlockGasMeter(ctx sdk.Context) storetypes.GasMeter {
 
 // retrieve the context for the tx w/ txBytes and other memoized values.
 func (app *BaseApp) getContextForTx(mode execMode, txBytes []byte) sdk.Context {
+	app.mu.Lock()
+	defer app.mu.Unlock()
+
 	modeState := app.getState(mode)
 	if modeState == nil {
 		panic(fmt.Sprintf("state is nil for mode %v", mode))