fix: x/gov/client/cli: fix integer overflow in parsing int prompted values (#13347)

Reported by cosmos/gosec in https://github.com/cosmos/cosmos-sdk/security/code-scanning/5730.
This change checks for errors from strconv.Atoi in which case we were
susceptible to out of range errors, this change also adds tests to
prevent regressions.

Fixes #13346

x/gov/client/cli/prompt.go

@@ -94,7 +94,16 @@ func Prompt[T any](data T, namePrefix string) (T, error) {
 		case reflect.String:
 			v.Field(i).SetString(result)
 		case reflect.Int:
-			resultInt, _ := strconv.Atoi(result)
+			resultInt, err := strconv.Atoi(result)
+			if err != nil {
+				return data, fmt.Errorf("invalid value for int: %w", err)
+			}
+			// If a value was successfully parsed the ranges of:
+			//      [minInt,     maxInt]
+			// are within the ranges of:
+			//      [minInt64, maxInt64]
+			// of which on 64-bit machines, which are most common,
+			// int==int64
 			v.Field(i).SetInt(int64(resultInt))
 		default:
 			// skip other types

x/gov/client/cli/prompt_test.go

@@ -0,0 +1,43 @@
+package cli_test
+
+import (
+	"sync"
+	"testing"
+
+	"github.com/chzyer/readline"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/cosmos/cosmos-sdk/x/gov/client/cli"
+)
+
+type st struct {
+	ToOverflow int
+}
+
+// On the tests running in Github actions, somehow there are races.
+var globalMu sync.Mutex
+
+// Tests that we successfully report overflows in parsing ints
+// See https://github.com/cosmos/cosmos-sdk/issues/13346
+func TestPromptIntegerOverflow(t *testing.T) {
+	// Intentionally sending a value out of the range of
+	intOverflowers := []string{
+		"-9223372036854775809",
+		"9223372036854775808",
+		"9923372036854775809",
+		"-9923372036854775809",
+		"18446744073709551616",
+		"-18446744073709551616",
+	}
+
+	for _, intOverflower := range intOverflowers {
+		overflowStr := intOverflower
+		t.Run(overflowStr, func(t *testing.T) {
+			readline.Stdout.Write([]byte(overflowStr + "\n"))
+
+			v, err := cli.Prompt(st{}, "")
+			assert.NotNil(t, err, "expected a report of an overflow")
+			assert.Equal(t, st{}, v, "expected a value of zero")
+		})
+	}
+}