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archive: check whiteout path before removal

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Ensure whiteout is not pointing to the current directory
or parent directory before removing. Protects against invalid
removal of the parent or current directory.

Add whiteout related tar tests using manufactured tar conditions.

Signed-off-by: Derek McGowan <derek@mcgstyle.net>
This commit is contained in:
Derek McGowan 2018-01-11 17:00:40 -08:00
parent 29ddd3d5fb
commit 384d46d8bd
No known key found for this signature in database
GPG Key ID: F58C5D0A4405ACDB
2 changed files with 177 additions and 4 deletions
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11
archive/tar.go
View File

@ -26,6 +26,8 @@ var bufferPool = &sync.Pool{
},
}
var errInvalidArchive = errors.New("invalid archive")
// Diff returns a tar stream of the computed filesystem
// difference between the provided directories.
//
@ -231,6 +233,15 @@ func applyNaive(ctx context.Context, root string, tr *tar.Reader, options ApplyO
originalBase := base[len(whiteoutPrefix):]
originalPath := filepath.Join(dir, originalBase)
// Ensure originalPath is under dir
if dir[len(dir)-1] != filepath.Separator {
dir += string(filepath.Separator)
}
if !strings.HasPrefix(originalPath, dir) {
return 0, errors.Wrapf(errInvalidArchive, "invalid whiteout name: %v", base)
}
if err := os.RemoveAll(originalPath); err != nil {
return 0, err
}

168
archive/tar_test.go
View File

@ -217,12 +217,47 @@ func TestBreakouts(t *testing.T) {
return nil
}
}
fileValue := func(f1 string, content []byte) func(string) error {
return func(root string) error {
b, err := ioutil.ReadFile(filepath.Join(root, f1))
if err != nil {
return err
}
if bytes.Compare(b, content) != 0 {
return errors.Errorf("content differs: expected %v, got %v", content, b)
}
return nil
}
}
fileNotExists := func(f1 string) func(string) error {
return func(root string) error {
_, err := os.Lstat(filepath.Join(root, f1))
if err == nil {
return errors.New("file exists")
} else if !os.IsNotExist(err) {
return err
}
return nil
}
}
all := func(funcs ...func(string) error) func(string) error {
return func(root string) error {
for _, f := range funcs {
if err := f(root); err != nil {
return err
}
}
return nil
}
}
breakouts := []struct {
name string
w WriterToTar
apply fstest.Applier
validator func(string) error
err error
}{
{
name: "SymlinkAbsolute",
@ -468,10 +503,129 @@ func TestBreakouts(t *testing.T) {
),
validator: notSameFile("/localetc/localpasswd", "/etc/passwd"),
},
{
name: "WhiteoutRootParent",
apply: fstest.Apply(
fstest.CreateDir("/etc/", 0755),
fstest.CreateFile("/etc/passwd", []byte("inside"), 0644),
),
w: TarAll(
tc.File(".wh...", []byte{}, 0644), // Should wipe out whole directory
),
err: errInvalidArchive,
},
{
name: "WhiteoutParent",
apply: fstest.Apply(
fstest.CreateDir("/etc/", 0755),
fstest.CreateFile("/etc/passwd", []byte("inside"), 0644),
),
w: TarAll(
tc.File("etc/.wh...", []byte{}, 0644),
),
err: errInvalidArchive,
},
{
name: "WhiteoutRoot",
apply: fstest.Apply(
fstest.CreateDir("/etc/", 0755),
fstest.CreateFile("/etc/passwd", []byte("inside"), 0644),
),
w: TarAll(
tc.File(".wh..", []byte{}, 0644),
),
err: errInvalidArchive,
},
{
name: "WhiteoutCurrentDirectory",
apply: fstest.Apply(
fstest.CreateDir("/etc/", 0755),
fstest.CreateFile("/etc/passwd", []byte("inside"), 0644),
),
w: TarAll(
tc.File("etc/.wh..", []byte{}, 0644), // Should wipe out whole directory
),
err: errInvalidArchive,
},
{
name: "WhiteoutSymlink",
apply: fstest.Apply(
fstest.CreateDir("/etc/", 0755),
fstest.CreateFile("/etc/passwd", []byte("all users"), 0644),
fstest.Symlink("/etc", "localetc"),
),
w: TarAll(
tc.File(".wh.localetc", []byte{}, 0644), // Should wipe out whole directory
),
validator: all(
fileValue("etc/passwd", []byte("all users")),
fileNotExists("localetc"),
),
},
{
// TODO: This test should change once archive apply is disallowing
// symlinks as parents in the name
name: "WhiteoutSymlinkPath",
apply: fstest.Apply(
fstest.CreateDir("/etc/", 0755),
fstest.CreateFile("/etc/passwd", []byte("all users"), 0644),
fstest.CreateFile("/etc/whitedout", []byte("ahhhh whiteout"), 0644),
fstest.Symlink("/etc", "localetc"),
),
w: TarAll(
tc.File("localetc/.wh.whitedout", []byte{}, 0644),
),
validator: all(
fileValue("etc/passwd", []byte("all users")),
fileNotExists("etc/whitedout"),
),
},
{
name: "WhiteoutDirectoryName",
apply: fstest.Apply(
fstest.CreateDir("/etc/", 0755),
fstest.CreateFile("/etc/passwd", []byte("all users"), 0644),
fstest.CreateFile("/etc/whitedout", []byte("ahhhh whiteout"), 0644),
fstest.Symlink("/etc", "localetc"),
),
w: TarAll(
tc.File(".wh.etc/somefile", []byte("non-empty"), 0644),
),
validator: all(
fileValue("etc/passwd", []byte("all users")),
fileValue(".wh.etc/somefile", []byte("non-empty")),
),
},
{
name: "WhiteoutDeadSymlinkParent",
apply: fstest.Apply(
fstest.CreateDir("/etc/", 0755),
fstest.CreateFile("/etc/passwd", []byte("all users"), 0644),
fstest.Symlink("/dne", "localetc"),
),
w: TarAll(
tc.File("localetc/.wh.etc", []byte{}, 0644),
),
// no-op, remove does not
validator: fileValue("etc/passwd", []byte("all users")),
},
{
name: "WhiteoutRelativePath",
apply: fstest.Apply(
fstest.CreateDir("/etc/", 0755),
fstest.CreateFile("/etc/passwd", []byte("all users"), 0644),
fstest.Symlink("/dne", "localetc"),
),
w: TarAll(
tc.File("dne/../.wh.etc", []byte{}, 0644),
),
// resolution ends up just removing etc
validator: fileNotExists("etc/passwd"),
},
}
for _, bo := range breakouts {
t.Run(bo.name, makeWriterToTarTest(bo.w, bo.apply, bo.validator))
t.Run(bo.name, makeWriterToTarTest(bo.w, bo.apply, bo.validator, bo.err))
}
}
@ -501,6 +655,7 @@ func TestApplyTar(t *testing.T) {
w WriterToTar
apply fstest.Applier
validator func(string) error
err error
}{
{
name: "DirectoryCreation",
@ -525,7 +680,7 @@ func TestApplyTar(t *testing.T) {
}
for _, at := range tests {
t.Run(at.name, makeWriterToTarTest(at.w, at.apply, at.validator))
t.Run(at.name, makeWriterToTarTest(at.w, at.apply, at.validator, at.err))
}
}
@ -636,7 +791,7 @@ func testDiffApply(appliers ...fstest.Applier) error {
return fstest.CheckDirectoryEqual(td, dest)
}
func makeWriterToTarTest(wt WriterToTar, a fstest.Applier, validate func(string) error) func(*testing.T) {
func makeWriterToTarTest(wt WriterToTar, a fstest.Applier, validate func(string) error, applyErr error) func(*testing.T) {
return func(t *testing.T) {
td, err := ioutil.TempDir("", "test-writer-to-tar-")
if err != nil {
@ -653,7 +808,14 @@ func makeWriterToTarTest(wt WriterToTar, a fstest.Applier, validate func(string)
tr := TarFromWriterTo(wt)
if _, err := Apply(context.Background(), td, tr); err != nil {
if applyErr == nil {
t.Fatalf("Failed to apply tar: %v", err)
} else if errors.Cause(err) != applyErr {
t.Fatalf("Unexpected apply error: %v, expected %v", err, applyErr)
}
return
} else if applyErr != nil {
t.Fatalf("Expected apply error, got none: %v", applyErr)
}
if validate != nil {