fix: x/gov/client/cli: fix integer overflow in parsing int prompted v…

…alues

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 +1,85 @@
+//go:build !race
+// +build !race
+
+// Disabled -race because the package github.com/manifoldco/[email protected]
+// has a data race and this code exposes it, but fixing it would require
+// holding up the associated change to this.
+
+package cli_test
+
+import (
+	"fmt"
+	"math"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/chzyer/readline"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/cosmos/cosmos-sdk/x/gov/client/cli"
+)
+
+type st struct {
+	I int
+}
+
+// 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) {
+			origStdin := readline.Stdin
+			fin, fw := readline.NewFillableStdin(os.Stdin)
+			readline.Stdin = fin
+			fw.Write([]byte(overflowStr + "\n"))
+			defer func() {
+				readline.Stdin = origStdin
+			}()
+
+			v, err := cli.Prompt(st{}, "")
+			assert.Equal(t, st{}, v, "expected a value of zero")
+			require.NotNil(t, err, "expected a report of an overflow")
+			require.Contains(t, err.Error(), "range")
+		})
+	}
+}
+
+func TestPromptParseInteger(t *testing.T) {
+	// Intentionally sending a value out of the range of
+	values := []struct {
+		in   string
+		want int
+	}{
+		{fmt.Sprintf("%d", math.MinInt), math.MinInt},
+		{"19991", 19991},
+		{"991000000199", 991000000199},
+	}
+
+	for _, tc := range values {
+		tc := tc
+		t.Run(tc.in, func(t *testing.T) {
+			origStdin := readline.Stdin
+			readline.Stdin = readline.NewCancelableStdin(strings.NewReader(tc.in + "\n"))
+			defer func() {
+				readline.Stdin = origStdin
+			}()
+
+			v, err := cli.Prompt(st{}, "")
+			assert.Nil(t, err, "expected a nil error")
+			assert.Equal(t, tc.want, v.I, "expected a value of zero")
+		})
+	}
+}