hooks: Harden when we accept push options that change repo settings

It is possible to change some repo settings (its visibility, and
template status) via `git push` options: `-o repo.private=true`, `-o
repo.template=true`.

Previously, there weren't sufficient permission checks on these, and
anyone who could `git push` to a repository - including via an AGit
workflow! - was able to change either of these settings. To guard
against this, the pre-receive hook will now check if either of these
options are present, and if so, will perform additional permission
checks to ensure that these can only be set by a repository owner or
an administrator. Additionally, changing these settings is disabled for
forks, even for the fork's owner.

There's still a case where the owner of a repository can change the
visibility of it, and it will not propagate to forks (it propagates to
forks when changing the visibility via the API), but that's an
inconsistency, not a security issue.

Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>
This commit is contained in:
Gergely Nagy 2024-04-15 10:07:45 +02:00 committed by Earl Warren
parent b7cff17de1
commit cc80e66153
No known key found for this signature in database
GPG key ID: 0579CB2928A78A00
2 changed files with 108 additions and 25 deletions

View file

@ -101,6 +101,57 @@ func (ctx *preReceiveContext) AssertCreatePullRequest() bool {
return true return true
} }
func (ctx *preReceiveContext) canChangeSettings() bool {
if !ctx.loadPusherAndPermission() {
return false
}
perm, err := access_model.GetUserRepoPermission(ctx, ctx.Repo.Repository, ctx.user)
if err != nil {
return false
}
if !perm.IsOwner() && !perm.IsAdmin() {
return false
}
if ctx.Repo.Repository.IsFork {
return false
}
return true
}
func (ctx *preReceiveContext) assertChangeSettings() bool {
opts := web.GetForm(ctx).(*private.HookOptions)
if len(opts.GitPushOptions) == 0 {
return true
}
_, hasPrivateOpt := opts.GitPushOptions[private.GitPushOptionRepoPrivate]
_, hasTemplateOpt := opts.GitPushOptions[private.GitPushOptionRepoTemplate]
if !hasPrivateOpt && !hasTemplateOpt {
// If neither `repo.private` nor `repo.template` is present in
// the push options, we're good to go without further permission
// checking.
return true
}
// Either `repo.private` or `repo.template` is among the push options,
// do some permission checks.
if !ctx.canChangeSettings() {
if ctx.Written() {
return false
}
ctx.JSON(http.StatusForbidden, private.Response{
UserMsg: "Permission denied for changing repo settings.",
})
return false
}
return true
}
// HookPreReceive checks whether a individual commit is acceptable // HookPreReceive checks whether a individual commit is acceptable
func HookPreReceive(ctx *gitea_context.PrivateContext) { func HookPreReceive(ctx *gitea_context.PrivateContext) {
opts := web.GetForm(ctx).(*private.HookOptions) opts := web.GetForm(ctx).(*private.HookOptions)
@ -111,6 +162,10 @@ func HookPreReceive(ctx *gitea_context.PrivateContext) {
opts: opts, opts: opts,
} }
if !ourCtx.assertChangeSettings() {
return
}
// Iterate across the provided old commit IDs // Iterate across the provided old commit IDs
for i := range opts.OldCommitIDs { for i := range opts.OldCommitIDs {
oldCommitID := opts.OldCommitIDs[i] oldCommitID := opts.OldCommitIDs[i]

View file

@ -8,29 +8,20 @@ import (
"testing" "testing"
"code.gitea.io/gitea/models/db" "code.gitea.io/gitea/models/db"
repo_model "code.gitea.io/gitea/models/repo"
"code.gitea.io/gitea/models/unittest" "code.gitea.io/gitea/models/unittest"
user_model "code.gitea.io/gitea/models/user" user_model "code.gitea.io/gitea/models/user"
"code.gitea.io/gitea/modules/git" repo_module "code.gitea.io/gitea/modules/repository"
repo_service "code.gitea.io/gitea/services/repository" repo_service "code.gitea.io/gitea/services/repository"
"github.com/stretchr/testify/require" "github.com/stretchr/testify/require"
) )
func TestGitPush(t *testing.T) { func TestOptionsGitPush(t *testing.T) {
onGiteaRun(t, testGitPush) onGiteaRun(t, testOptionsGitPush)
} }
func testGitPush(t *testing.T, u *url.URL) { func testOptionsGitPush(t *testing.T, u *url.URL) {
t.Run("Push branch with options", func(t *testing.T) {
runTestGitPush(t, u, func(t *testing.T, gitPath string) {
branchName := "branch-with-options"
doGitCreateBranch(gitPath, branchName)(t)
doGitPushTestRepository(gitPath, "origin", branchName, "-o", "repo.private=true", "-o", "repo.template=true")(t)
})
})
}
func runTestGitPush(t *testing.T, u *url.URL, gitOperation func(t *testing.T, gitPath string)) {
user := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2}) user := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
repo, err := repo_service.CreateRepository(db.DefaultContext, user, user, repo_service.CreateRepoOptions{ repo, err := repo_service.CreateRepository(db.DefaultContext, user, user, repo_service.CreateRepoOptions{
Name: "repo-to-push", Name: "repo-to-push",
@ -46,22 +37,59 @@ func runTestGitPush(t *testing.T, u *url.URL, gitOperation func(t *testing.T, gi
doGitInitTestRepository(gitPath)(t) doGitInitTestRepository(gitPath)(t)
oldPath := u.Path
oldUser := u.User
defer func() {
u.Path = oldPath
u.User = oldUser
}()
u.Path = repo.FullName() + ".git" u.Path = repo.FullName() + ".git"
u.User = url.UserPassword(user.LowerName, userPassword) u.User = url.UserPassword(user.LowerName, userPassword)
doGitAddRemote(gitPath, "origin", u)(t) doGitAddRemote(gitPath, "origin", u)(t)
gitRepo, err := git.OpenRepository(git.DefaultContext, gitPath) {
require.NoError(t, err) // owner sets private & template to true via push options
defer gitRepo.Close() branchName := "branch1"
doGitCreateBranch(gitPath, branchName)(t)
doGitPushTestRepository(gitPath, "origin", branchName, "-o", "repo.private=true", "-o", "repo.template=true")(t)
repo, err := repo_model.GetRepositoryByOwnerAndName(db.DefaultContext, user.Name, "repo-to-push")
require.NoError(t, err)
require.True(t, repo.IsPrivate)
require.True(t, repo.IsTemplate)
}
gitOperation(t, gitPath) {
// owner sets private & template to false via push options
branchName := "branch2"
doGitCreateBranch(gitPath, branchName)(t)
doGitPushTestRepository(gitPath, "origin", branchName, "-o", "repo.private=false", "-o", "repo.template=false")(t)
repo, err = repo_model.GetRepositoryByOwnerAndName(db.DefaultContext, user.Name, "repo-to-push")
require.NoError(t, err)
require.False(t, repo.IsPrivate)
require.False(t, repo.IsTemplate)
}
{
// create a collaborator with write access
collaborator := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 5})
u.User = url.UserPassword(collaborator.LowerName, userPassword)
doGitAddRemote(gitPath, "collaborator", u)(t)
repo, err := repo_model.GetRepositoryByOwnerAndName(db.DefaultContext, user.Name, "repo-to-push")
require.NoError(t, err)
repo_module.AddCollaborator(db.DefaultContext, repo, collaborator)
}
{
// collaborator with write access is allowed to push
branchName := "branch3"
doGitCreateBranch(gitPath, branchName)(t)
doGitPushTestRepository(gitPath, "collaborator", branchName)(t)
}
{
// collaborator with write access fails to change private & template via push options
branchName := "branch4"
doGitCreateBranch(gitPath, branchName)(t)
doGitPushTestRepositoryFail(gitPath, "collaborator", branchName, "-o", "repo.private=true", "-o", "repo.template=true")(t)
repo, err = repo_model.GetRepositoryByOwnerAndName(db.DefaultContext, user.Name, "repo-to-push")
require.NoError(t, err)
require.False(t, repo.IsPrivate)
require.False(t, repo.IsTemplate)
}
require.NoError(t, repo_service.DeleteRepositoryDirectly(db.DefaultContext, user, user.ID, repo.ID)) require.NoError(t, repo_service.DeleteRepositoryDirectly(db.DefaultContext, user, user.ID, repo.ID))
} }