mirror of
https://codeberg.org/forgejo/forgejo.git
synced 2026-03-25 17:03:05 -04:00
f93d2cb261
One of the security patches released 2026-03-09 [fixed a vulnerability](d1c7b04d09) caused by a misapplication of Go `case` statements, where the implementation would have been correct if Go `case` statements automatically fall through to the next case block, but they do not. This PR adds a semgrep rule which detects any empty `case` statement and raises an error, in order to prevent this coding mistake in the future.
For example, code like this will now trigger a build error:
```go
switch setting.Protocol {
case setting.HTTPUnix:
case setting.FCGI:
case setting.FCGIUnix:
default:
defaultLocalURL := string(setting.Protocol) + "://"
}
```
Example error:
```
cmd/web.go
❯❯❱ semgrep.config.forgejo-switch-empty-case
switch has a case block with no content. This is treated as "break" by Go, but developers may
confuse it for "fallthrough". To fix this error, disambiguate by using "break" or
"fallthrough".
279┆ switch setting.Protocol {
280┆ case setting.HTTPUnix:
281┆ case setting.FCGI:
282┆ case setting.FCGIUnix:
283┆ default:
284┆ defaultLocalURL := string(setting.Protocol) + "://"
285┆ if setting.HTTPAddr == "0.0.0.0" {
286┆ defaultLocalURL += "localhost"
287┆ } else {
288┆ defaultLocalURL += setting.HTTPAddr
```
As described in the error output, this error can be fixed by explicitly listing `break` (the real Go behaviour, to do nothing in the block), or by listing `fallthrough` (if the intent was to fall through).
All existing code triggering this detection has been changed to `break` (or, rarely, irrelevant cases have been removed), which should maintain the same code functionality. While performing this fixup, a light analysis was performed on each case and they *appeared* correct, but with ~65 cases I haven't gone into extreme depth.
Tests are present for the semgrep rule in `.semgrep/tests/go.go`.
## Checklist
The [contributor guide](https://forgejo.org/docs/next/contributor/) contains information that will be helpful to first time contributors. There also are a few [conditions for merging Pull Requests in Forgejo repositories](https://codeberg.org/forgejo/governance/src/branch/main/PullRequestsAgreement.md). You are also welcome to join the [Forgejo development chatroom](https://matrix.to/#/#forgejo-development:matrix.org).
### Documentation
- [ ] I created a pull request [to the documentation](https://codeberg.org/forgejo/docs) to explain to Forgejo users how to use this change.
- [x] I did not document these changes and I do not expect someone else to do it.
### Release notes
- [ ] This change will be noticed by a Forgejo user or admin (feature, bug fix, performance, etc.). I suggest to include a release note for this change.
- [x] This change is not visible to a Forgejo user or admin (refactor, dependency upgrade, etc.). I think there is no need to add a release note for this change.
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/11593
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Co-authored-by: Mathieu Fenniak <mathieu@fenniak.net>
Co-committed-by: Mathieu Fenniak <mathieu@fenniak.net>
70 lines
1.5 KiB
Go
70 lines
1.5 KiB
Go
// Copyright 2020 The Gitea Authors. All rights reserved.
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// SPDX-License-Identifier: MIT
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package eventsource
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import "sync"
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// Messenger is a per uid message store
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type Messenger struct {
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mutex sync.Mutex
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uid int64
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channels []chan *Event
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}
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// NewMessenger creates a messenger for a particular uid
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func NewMessenger(uid int64) *Messenger {
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return &Messenger{
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uid: uid,
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channels: [](chan *Event){},
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}
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}
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// Register returns a new chan []byte
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func (m *Messenger) Register() <-chan *Event {
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m.mutex.Lock()
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// TODO: Limit the number of messengers per uid
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channel := make(chan *Event, 1)
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m.channels = append(m.channels, channel)
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m.mutex.Unlock()
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return channel
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}
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// Unregister removes the provider chan []byte
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func (m *Messenger) Unregister(channel <-chan *Event) bool {
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m.mutex.Lock()
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defer m.mutex.Unlock()
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for i, toRemove := range m.channels {
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if channel == toRemove {
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m.channels = append(m.channels[:i], m.channels[i+1:]...)
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close(toRemove)
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break
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}
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}
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return len(m.channels) == 0
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}
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// UnregisterAll removes all chan []byte
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func (m *Messenger) UnregisterAll() {
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m.mutex.Lock()
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defer m.mutex.Unlock()
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for _, channel := range m.channels {
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close(channel)
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}
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m.channels = nil
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}
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// SendMessage sends the message to all registered channels
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func (m *Messenger) SendMessage(message *Event) {
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m.mutex.Lock()
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defer m.mutex.Unlock()
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for i := range m.channels {
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channel := m.channels[i]
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select {
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case channel <- message:
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break
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default:
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break
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}
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}
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}
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