Fail with error when double-rendering text in markdownify/RenderString

This commit prevents the most commons case of infinite recursion in link render hooks when the `linkify` option is enabled (see below). This is always a user error, but getting a `stack overflow` (the current stack limit in Go is 1 GB on 64-bit, 250 MB on 32-bit) error isn't very helpful. This fix will not prevent all such errors, though, but we may do better once #9570 is in place.

So, these will fail:

```
<a href="{{ .Destination | safeURL }}" >{{ .Text | markdownify }}</a>
<a href="{{ .Destination | safeURL }}" >{{ .Text | .Page.RenderString }}</a>
```

`.Text` is already rendered to `HTML`. The above needs to be rewritten to:

```
<a href="{{ .Destination | safeURL }}" >{{ .Text | safeHTML }}</a>
<a href="{{ .Destination | safeURL }}" >{{ .Text | safeHTML }}</a>
```

Fixes #8959
This commit is contained in:
Bjørn Erik Pedersen 2022-03-10 08:19:03 +01:00 committed by GitHub
parent 5697348e17
commit 4e14cf7607
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
7 changed files with 122 additions and 20 deletions

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@ -0,0 +1,20 @@
// Copyright 2022 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package hstring
type RenderedString string
func (s RenderedString) String() string {
return string(s)
}

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@ -0,0 +1,30 @@
// Copyright 2022 The Hugo Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package hstring
import (
"html/template"
"testing"
qt "github.com/frankban/quicktest"
"github.com/spf13/cast"
)
func TestStringTypes(t *testing.T) {
c := qt.New(t)
// Validate that it will behave like a string in Hugo settings.
c.Assert(cast.ToString(RenderedString("Hugo")), qt.Equals, "Hugo")
c.Assert(template.HTML(RenderedString("Hugo")), qt.Equals, template.HTML("Hugo"))
}

View file

@ -24,6 +24,7 @@ import (
"unicode/utf8"
"github.com/gohugoio/hugo/common/text"
"github.com/gohugoio/hugo/common/types/hstring"
"github.com/gohugoio/hugo/identity"
"github.com/mitchellh/mapstructure"
"github.com/pkg/errors"
@ -351,8 +352,16 @@ func (p *pageContentOutput) RenderString(args ...interface{}) (template.HTML, er
}
}
contentToRender := args[sidx]
if _, ok := contentToRender.(hstring.RenderedString); ok {
// This content is already rendered, this is potentially
// a infinite recursion.
return "", errors.New("text is already rendered, repeating it may cause infinite recursion")
}
var err error
s, err = cast.ToStringE(args[sidx])
s, err = cast.ToStringE(contentToRender)
if err != nil {
return "", err
}
@ -515,7 +524,6 @@ func (p *pageContentOutput) initRenderHooks() error {
}
}
}
if !found1 {
if tp == hooks.CodeBlockRendererType {
// No user provided tempplate for code blocks, so we use the native Go code version -- which is also faster.

View file

@ -18,6 +18,7 @@ import (
"github.com/gohugoio/hugo/common/hugio"
"github.com/gohugoio/hugo/common/text"
"github.com/gohugoio/hugo/common/types/hstring"
"github.com/gohugoio/hugo/identity"
"github.com/gohugoio/hugo/markup/internal/attributes"
)
@ -32,7 +33,7 @@ type LinkContext interface {
Page() interface{}
Destination() string
Title() string
Text() string
Text() hstring.RenderedString
PlainText() string
}
@ -75,7 +76,7 @@ type HeadingContext interface {
// Anchor is the HTML id assigned to the heading.
Anchor() string
// Text is the rendered (HTML) heading text, excluding the heading marker.
Text() string
Text() hstring.RenderedString
// PlainText is the unrendered version of Text.
PlainText() string

View file

@ -18,6 +18,8 @@ import (
"strings"
"testing"
qt "github.com/frankban/quicktest"
"github.com/gohugoio/hugo/hugolib"
)
@ -395,6 +397,49 @@ FENCE
}
}
// Iisse #8959
func TestHookInfiniteRecursion(t *testing.T) {
t.Parallel()
for _, renderFunc := range []string{"markdownify", ".Page.RenderString"} {
t.Run(renderFunc, func(t *testing.T) {
files := `
-- config.toml --
-- layouts/_default/_markup/render-link.html --
<a href="{{ .Destination | safeURL }}">{{ .Text | RENDERFUNC }}</a>
-- layouts/_default/single.html --
{{ .Content }}
-- content/p1.md --
---
title: "p1"
---
https://example.org
a@b.com
`
files = strings.ReplaceAll(files, "RENDERFUNC", renderFunc)
b, err := hugolib.NewIntegrationTestBuilder(
hugolib.IntegrationTestConfig{
T: t,
TxtarString: files,
},
).BuildE()
b.Assert(err, qt.IsNotNil)
b.Assert(err.Error(), qt.Contains, "text is already rendered, repeating it may cause infinite recursion")
})
}
}
// Issue 9594
func TestQuotesInImgAltAttr(t *testing.T) {
t.Parallel()

View file

@ -17,6 +17,7 @@ import (
"bytes"
"strings"
"github.com/gohugoio/hugo/common/types/hstring"
"github.com/gohugoio/hugo/markup/converter/hooks"
"github.com/gohugoio/hugo/markup/goldmark/goldmark_config"
"github.com/gohugoio/hugo/markup/goldmark/internal/render"
@ -49,7 +50,7 @@ type linkContext struct {
page interface{}
destination string
title string
text string
text hstring.RenderedString
plainText string
}
@ -65,7 +66,7 @@ func (ctx linkContext) Page() interface{} {
return ctx.page
}
func (ctx linkContext) Text() string {
func (ctx linkContext) Text() hstring.RenderedString {
return ctx.text
}
@ -81,7 +82,7 @@ type headingContext struct {
page interface{}
level int
anchor string
text string
text hstring.RenderedString
plainText string
*attributes.AttributesHolder
}
@ -98,7 +99,7 @@ func (ctx headingContext) Anchor() string {
return ctx.anchor
}
func (ctx headingContext) Text() string {
func (ctx headingContext) Text() hstring.RenderedString {
return ctx.text
}
@ -156,7 +157,7 @@ func (r *hookedRenderer) renderImage(w util.BufWriter, source []byte, node ast.N
page: ctx.DocumentContext().Document,
destination: string(n.Destination),
title: string(n.Title),
text: string(text),
text: hstring.RenderedString(text),
plainText: string(n.Text(source)),
},
)
@ -226,7 +227,7 @@ func (r *hookedRenderer) renderLink(w util.BufWriter, source []byte, node ast.No
page: ctx.DocumentContext().Document,
destination: string(n.Destination),
title: string(n.Title),
text: string(text),
text: hstring.RenderedString(text),
plainText: string(n.Text(source)),
},
)
@ -293,7 +294,7 @@ func (r *hookedRenderer) renderAutoLink(w util.BufWriter, source []byte, node as
linkContext{
page: ctx.DocumentContext().Document,
destination: url,
text: label,
text: hstring.RenderedString(label),
plainText: label,
},
)
@ -381,7 +382,7 @@ func (r *hookedRenderer) renderHeading(w util.BufWriter, source []byte, node ast
page: ctx.DocumentContext().Document,
level: n.Level,
anchor: string(anchor),
text: string(text),
text: hstring.RenderedString(text),
plainText: string(n.Text(source)),
AttributesHolder: attributes.New(n.Attributes(), attributes.AttributesOwnerGeneral),
},

View file

@ -20,7 +20,6 @@ import (
"github.com/alecthomas/chroma/lexers"
"github.com/gohugoio/hugo/cache/namedmemcache"
"github.com/gohugoio/hugo/common/herrors"
"github.com/gohugoio/hugo/markup/converter/hooks"
"github.com/gohugoio/hugo/markup/highlight"
@ -119,20 +118,18 @@ func (ns *Namespace) HTMLUnescape(s interface{}) (string, error) {
// Markdownify renders a given input from Markdown to HTML.
func (ns *Namespace) Markdownify(s interface{}) (template.HTML, error) {
defer herrors.Recover()
ss, err := cast.ToStringE(s)
if err != nil {
return "", err
}
home := ns.deps.Site.Home()
if home == nil {
panic("home must not be nil")
}
sss, err := home.RenderString(ss)
ss, err := home.RenderString(s)
if err != nil {
return "", err
}
// Strip if this is a short inline type of text.
bb := ns.deps.ContentSpec.TrimShortHTML([]byte(sss))
bb := ns.deps.ContentSpec.TrimShortHTML([]byte(ss))
return helpers.BytesToHTML(bb), nil
}