From 5f79550a0dade6a6cebdf8cf62f55ffa6df30b30 Mon Sep 17 00:00:00 2001
From: KN4CK3R <admin@oldschoolhack.me>
Date: Wed, 21 Feb 2024 19:54:17 +0100
Subject: [PATCH] Prevent double use of `git cat-file` session. (#29298)
Fixes the reason why #29101 is hard to replicate.
Related #29297
Create a repo with a file with minimum size 4097 bytes (I use 10000) and
execute the following code:
```go
gitRepo, err := gitrepo.OpenRepository(db.DefaultContext, <repo>)
assert.NoError(t, err)
commit, err := gitRepo.GetCommit(<sha>)
assert.NoError(t, err)
entry, err := commit.GetTreeEntryByPath(<file>)
assert.NoError(t, err)
b := entry.Blob()
// Create a reader
r, err := b.DataAsync()
assert.NoError(t, err)
defer r.Close()
// Create a second reader
r2, err := b.DataAsync()
assert.NoError(t, err) // Should be no error but is ErrNotExist
defer r2.Close()
```
The problem is the check in `CatFileBatch`:
https://github.com/go-gitea/gitea/blob/79217ea63c1f77de7ca79813ae45950724e63d02/modules/git/repo_base_nogogit.go#L81-L87
`Buffered() > 0` is used to check if there is a "operation" in progress
at the moment. This is a problem because we can't control the internal
buffer in the `bufio.Reader`. The code above demonstrates a sequence
which initiates an operation for which the code thinks there is no
active processing. The second call to `DataAsync()` therefore reuses the
existing instances instead of creating a new batch reader.
(cherry picked from commit f74c869221624092999097af38b6f7fae4701420)
---
modules/git/repo_base_nogogit.go | 21 ++++++++++-----
tests/integration/git_test.go | 44 ++++++++++++++++++++++++++++++++
2 files changed, 59 insertions(+), 6 deletions(-)
diff --git a/modules/git/repo_base_nogogit.go b/modules/git/repo_base_nogogit.go
index d5a350a926..8c6eae5897 100644
--- a/modules/git/repo_base_nogogit.go
+++ b/modules/git/repo_base_nogogit.go
@@ -27,10 +27,12 @@ type Repository struct {
gpgSettings *GPGSettings
+ batchInUse bool
batchCancel context.CancelFunc
batchReader *bufio.Reader
batchWriter WriteCloserError
+ checkInUse bool
checkCancel context.CancelFunc
checkReader *bufio.Reader
checkWriter WriteCloserError
@@ -79,23 +81,28 @@ func OpenRepository(ctx context.Context, repoPath string) (*Repository, error) {
// CatFileBatch obtains a CatFileBatch for this repository
func (repo *Repository) CatFileBatch(ctx context.Context) (WriteCloserError, *bufio.Reader, func()) {
- if repo.batchCancel == nil || repo.batchReader.Buffered() > 0 {
+ if repo.batchCancel == nil || repo.batchInUse {
log.Debug("Opening temporary cat file batch for: %s", repo.Path)
return CatFileBatch(ctx, repo.Path)
}
- return repo.batchWriter, repo.batchReader, func() {}
+ repo.batchInUse = true
+ return repo.batchWriter, repo.batchReader, func() {
+ repo.batchInUse = false
+ }
}
// CatFileBatchCheck obtains a CatFileBatchCheck for this repository
func (repo *Repository) CatFileBatchCheck(ctx context.Context) (WriteCloserError, *bufio.Reader, func()) {
- if repo.checkCancel == nil || repo.checkReader.Buffered() > 0 {
- log.Debug("Opening temporary cat file batch-check: %s", repo.Path)
+ if repo.checkCancel == nil || repo.checkInUse {
+ log.Debug("Opening temporary cat file batch-check for: %s", repo.Path)
return CatFileBatchCheck(ctx, repo.Path)
}
- return repo.checkWriter, repo.checkReader, func() {}
+ repo.checkInUse = true
+ return repo.checkWriter, repo.checkReader, func() {
+ repo.checkInUse = false
+ }
}
-// Close this repository, in particular close the underlying gogitStorage if this is not nil
func (repo *Repository) Close() (err error) {
if repo == nil {
return nil
@@ -105,12 +112,14 @@ func (repo *Repository) Close() (err error) {
repo.batchReader = nil
repo.batchWriter = nil
repo.batchCancel = nil
+ repo.batchInUse = false
}
if repo.checkCancel != nil {
repo.checkCancel()
repo.checkCancel = nil
repo.checkReader = nil
repo.checkWriter = nil
+ repo.checkInUse = false
}
repo.LastCommitCache = nil
repo.tagCache = nil
diff --git a/tests/integration/git_test.go b/tests/integration/git_test.go
index 365e7f91b1..ff5421d93a 100644
--- a/tests/integration/git_test.go
+++ b/tests/integration/git_test.go
@@ -4,6 +4,7 @@
package integration
import (
+ "bytes"
"encoding/hex"
"fmt"
"math/rand"
@@ -26,9 +27,11 @@ import (
user_model "code.gitea.io/gitea/models/user"
gitea_context "code.gitea.io/gitea/modules/context"
"code.gitea.io/gitea/modules/git"
+ "code.gitea.io/gitea/modules/gitrepo"
"code.gitea.io/gitea/modules/lfs"
"code.gitea.io/gitea/modules/setting"
api "code.gitea.io/gitea/modules/structs"
+ files_service "code.gitea.io/gitea/services/repository/files"
"code.gitea.io/gitea/tests"
"github.com/stretchr/testify/assert"
@@ -1034,3 +1037,44 @@ func doCreateAgitFlowPull(dstPath string, ctx *APITestContext, baseBranch, headB
t.Run("CheckoutMasterAgain", doGitCheckoutBranch(dstPath, "master"))
}
}
+
+func TestDataAsync_Issue29101(t *testing.T) {
+ onGiteaRun(t, func(t *testing.T, u *url.URL) {
+ user := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
+ repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})
+
+ resp, err := files_service.ChangeRepoFiles(db.DefaultContext, repo, user, &files_service.ChangeRepoFilesOptions{
+ Files: []*files_service.ChangeRepoFile{
+ {
+ Operation: "create",
+ TreePath: "test.txt",
+ ContentReader: bytes.NewReader(make([]byte, 10000)),
+ },
+ },
+ OldBranch: repo.DefaultBranch,
+ NewBranch: repo.DefaultBranch,
+ })
+ assert.NoError(t, err)
+
+ sha := resp.Commit.SHA
+
+ gitRepo, err := gitrepo.OpenRepository(db.DefaultContext, repo)
+ assert.NoError(t, err)
+
+ commit, err := gitRepo.GetCommit(sha)
+ assert.NoError(t, err)
+
+ entry, err := commit.GetTreeEntryByPath("test.txt")
+ assert.NoError(t, err)
+
+ b := entry.Blob()
+
+ r, err := b.DataAsync()
+ assert.NoError(t, err)
+ defer r.Close()
+
+ r2, err := b.DataAsync()
+ assert.NoError(t, err)
+ defer r2.Close()
+ })
+}