flag: validate Int and Uint values to be in range

Fixes #19230

Change-Id: I38df9732b88f0328506e74f1a46f52adf47db1e5
Reviewed-on: https://go-review.googlesource.com/38419
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/flag/flag.go b/src/flag/flag.go
index bbbc55a2799dc86bcc4338500c2c4e1732268f20..b166c5753adfb71b84f8533303e307bf1fc365aa 100644 (file)
--- a/src/flag/flag.go
+++ b/src/flag/flag.go
@@ -114,7 +114,7 @@ func newIntValue(val int, p *int) *intValue {
 }
 
 func (i *intValue) Set(s string) error {
-       v, err := strconv.ParseInt(s, 0, 64)
+       v, err := strconv.ParseInt(s, 0, strconv.IntSize)
        *i = intValue(v)
        return err
 }
@@ -150,7 +150,7 @@ func newUintValue(val uint, p *uint) *uintValue {
 }
 
 func (i *uintValue) Set(s string) error {
-       v, err := strconv.ParseUint(s, 0, 64)
+       v, err := strconv.ParseUint(s, 0, strconv.IntSize)
        *i = uintValue(v)
        return err
 }

diff --git a/src/flag/flag_test.go b/src/flag/flag_test.go
index e2319ec94c8691f83c30b0c9e9fdeb73903d2e13..02da2c775063dd1e9b77d04bc8a314ba09fe14a3 100644 (file)
--- a/src/flag/flag_test.go
+++ b/src/flag/flag_test.go
@@ -10,6 +10,7 @@ import (
        "fmt"
        "os"
        "sort"
+       "strconv"
        "strings"
        "testing"
        "time"
@@ -415,3 +416,19 @@ func TestPrintDefaults(t *testing.T) {
                t.Errorf("got %q want %q\n", got, defaultOutput)
        }
 }
+
+// Issue 19230: validate range of Int and Uint flag values.
+func TestIntFlagOverflow(t *testing.T) {
+       if strconv.IntSize != 32 {
+               return
+       }
+       ResetForTesting(nil)
+       Int("i", 0, "")
+       Uint("u", 0, "")
+       if err := Set("i", "2147483648"); err == nil {
+               t.Error("unexpected success setting Int")
+       }
+       if err := Set("u", "4294967296"); err == nil {
+               t.Error("unexpected success setting Uint")
+       }
+}