tpl: add sanity check to prevent panic in seq on big nums

Fixes #1092

diff --git a/helpers/general.go b/helpers/general.go
index f6e0cbc4f3248fbf6f6ffa1c133490f47cc24dad..dc9029b0635fa0e3df05e7fbb84cf65482c25a2d 100644 (file)
--- a/helpers/general.go
+++ b/helpers/general.go
@@ -264,10 +264,14 @@ func Seq(args ...interface{}) ([]int, error) {
                }
        }
 
+       // sanity check
+       if last < -100000 {
+               return nil, errors.New("size of result exeeds limit")
+       }
        size := int(((last - first) / inc) + 1)
 
        // sanity check
-       if size > 2000 {
+       if size <= 0 || size > 2000 {
                return nil, errors.New("size of result exeeds limit")
        }
 

diff --git a/tpl/template_test.go b/tpl/template_test.go
index c7cd20f55258467d784887b3d63b5728836f7ea9..0c68516e566498c1a49049499b7c23ee07d10556 100644 (file)
--- a/tpl/template_test.go
+++ b/tpl/template_test.go
@@ -8,6 +8,11 @@ import (
 
 // Test for bugs discovered by https://github.com/dvyukov/go-fuzz
 func TestTplGoFuzzReports(t *testing.T) {
+
+       // The following test case(s) also fail
+       // See https://github.com/golang/go/issues/10634
+       //{"{{ seq 433937734937734969526500969526500 }}", 2}}
+
        for i, this := range []struct {
                data      string
                expectErr int
@@ -17,7 +22,8 @@ func TestTplGoFuzzReports(t *testing.T) {
                // Issue #1090
                {"{{ slicestr \"000000\" 10}}", 2},
                // Issue #1091
-               {"{{apply .C \"first\" 0 0 0}}", 2}} {
+               {"{{apply .C \"first\" 0 0 0}}", 2},
+               {"{{seq 3e80}}", 2}} {
                templ := New()
 
                d := &Data{
@@ -26,6 +32,9 @@ func TestTplGoFuzzReports(t *testing.T) {
                        C: []int{1, 2, 3},
                        D: map[int]string{1: "foo", 2: "bar"},
                        E: Data1{42, "foo"},
+                       F: []string{"a", "b", "c"},
+                       G: []string{"a", "b", "c", "d", "e"},
+                       H: "a,b,c,d,e,f",
                }
 
                err := templ.AddTemplate("fuzz", this.data)
@@ -52,6 +61,9 @@ type Data struct {
        C []int
        D map[int]string
        E Data1
+       F []string
+       G []string
+       H string
 }
 
 type Data1 struct {