make image listing more resilient

Handle more TOCTOUs operating on listed images.  Also pull in
containers/common/pull/1520 and containers/common/pull/1522 which do the
same on the internal layer tree.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2216700
Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>
This commit is contained in:
Valentin Rothberg
2023-06-23 13:43:36 +02:00
parent 1bca2d6a1e
commit db37d66cd1
11 changed files with 202 additions and 67 deletions

View File

@@ -402,7 +402,7 @@ func (i *Image) removeRecursive(ctx context.Context, rmMap map[string]*RemoveIma
// have a closer look at the errors. On top, image removal should be
// tolerant toward corrupted images.
handleError := func(err error) error {
if errors.Is(err, storage.ErrImageUnknown) || errors.Is(err, storage.ErrNotAnImage) || errors.Is(err, storage.ErrLayerUnknown) {
if ErrorIsImageUnknown(err) {
// The image or layers of the image may already have been removed
// in which case we consider the image to be removed.
return nil

View File

@@ -2,8 +2,10 @@ package libimage
import (
"context"
"errors"
"github.com/containers/storage"
storageTypes "github.com/containers/storage/types"
ociv1 "github.com/opencontainers/image-spec/specs-go/v1"
"github.com/sirupsen/logrus"
)
@@ -30,7 +32,19 @@ func (t *layerTree) node(layerID string) *layerNode {
return node
}
// ErrorIsImageUnknown returns true if the specified error indicates that an
// image is unknown or has been partially removed (e.g., a missing layer).
func ErrorIsImageUnknown(err error) bool {
return errors.Is(err, storage.ErrImageUnknown) ||
errors.Is(err, storageTypes.ErrLayerUnknown) ||
errors.Is(err, storageTypes.ErrSizeUnknown) ||
errors.Is(err, storage.ErrNotAnImage)
}
// toOCI returns an OCI image for the specified image.
//
// WARNING: callers are responsible for handling cases where the target image
// has been (partially) removed and can use `ErrorIsImageUnknown` to detect it.
func (t *layerTree) toOCI(ctx context.Context, i *Image) (*ociv1.Image, error) {
var err error
oci, exists := t.ociCache[i.ID()]
@@ -155,6 +169,9 @@ func (t *layerTree) children(ctx context.Context, parent *Image, all bool) ([]*I
parentID := parent.ID()
parentOCI, err := t.toOCI(ctx, parent)
if err != nil {
if ErrorIsImageUnknown(err) {
return nil, nil
}
return nil, err
}
@@ -165,6 +182,9 @@ func (t *layerTree) children(ctx context.Context, parent *Image, all bool) ([]*I
}
childOCI, err := t.toOCI(ctx, child)
if err != nil {
if ErrorIsImageUnknown(err) {
return false, nil
}
return false, err
}
// History check.
@@ -255,6 +275,9 @@ func (t *layerTree) parent(ctx context.Context, child *Image) (*Image, error) {
childID := child.ID()
childOCI, err := t.toOCI(ctx, child)
if err != nil {
if ErrorIsImageUnknown(err) {
return nil, nil
}
return nil, err
}
@@ -268,6 +291,9 @@ func (t *layerTree) parent(ctx context.Context, child *Image) (*Image, error) {
}
emptyOCI, err := t.toOCI(ctx, empty)
if err != nil {
if ErrorIsImageUnknown(err) {
return nil, nil
}
return nil, err
}
// History check.
@@ -300,6 +326,9 @@ func (t *layerTree) parent(ctx context.Context, child *Image) (*Image, error) {
}
parentOCI, err := t.toOCI(ctx, parent)
if err != nil {
if ErrorIsImageUnknown(err) {
return nil, nil
}
return nil, err
}
// History check.

View File

@@ -69,8 +69,6 @@ type SetupOptions struct {
ContainerID string
// Netns path to the netns
Netns string
// ContainerPID is the pid of container process
ContainerPID int
// Ports the should be forwarded
Ports []types.PortMapping
// ExtraOptions for slirp4netns that were set on the cli
@@ -84,6 +82,9 @@ type SetupOptions struct {
// RootlessPortSyncPipe pipe used to exit the rootlessport process.
// Same as Slirp4netnsExitPipeR, except this is only used when ports are given.
RootlessPortExitPipeR *os.File
// Pdeathsig is the signal which is send to slirp4netns process if the calling thread
// exits. The caller is responsible for locking the thread with runtime.LockOSThread().
Pdeathsig syscall.Signal
}
// SetupResult return type from Setup()
@@ -309,7 +310,8 @@ func Setup(opts *SetupOptions) (*SetupResult, error) {
cmd := exec.Command(path, cmdArgs...)
logrus.Debugf("slirp4netns command: %s", strings.Join(cmd.Args, " "))
cmd.SysProcAttr = &syscall.SysProcAttr{
Setpgid: true,
Setpgid: true,
Pdeathsig: opts.Pdeathsig,
}
// workaround for https://github.com/rootless-containers/slirp4netns/pull/153

View File

@@ -16,16 +16,50 @@ import (
// DefaultPostKillTimeout is the recommended default post-kill timeout.
const DefaultPostKillTimeout = time.Duration(10) * time.Second
type RunOptions struct {
// The hook to run
Hook *rspec.Hook
// The workdir to change when invoking the hook
Dir string
// The container state data to pass into the hook process
State []byte
// Stdout from the hook process
Stdout io.Writer
// Stderr from the hook process
Stderr io.Writer
// Timeout for waiting process killed
PostKillTimeout time.Duration
}
// Run executes the hook and waits for it to complete or for the
// context or hook-specified timeout to expire.
//
// Deprecated: Too many arguments, has been refactored and replaced by RunWithOptions instead
func Run(ctx context.Context, hook *rspec.Hook, state []byte, stdout io.Writer, stderr io.Writer, postKillTimeout time.Duration) (hookErr, err error) {
return RunWithOptions(
ctx,
RunOptions{
Hook: hook,
State: state,
Stdout: stdout,
Stderr: stderr,
PostKillTimeout: postKillTimeout,
},
)
}
// RunWithOptions executes the hook and waits for it to complete or for the
// context or hook-specified timeout to expire.
func RunWithOptions(ctx context.Context, options RunOptions) (hookErr, err error) {
hook := options.Hook
cmd := osexec.Cmd{
Path: hook.Path,
Args: hook.Args,
Env: hook.Env,
Stdin: bytes.NewReader(state),
Stdout: stdout,
Stderr: stderr,
Dir: options.Dir,
Stdin: bytes.NewReader(options.State),
Stdout: options.Stdout,
Stderr: options.Stderr,
}
if cmd.Env == nil {
cmd.Env = []string{}
@@ -57,11 +91,11 @@ func Run(ctx context.Context, hook *rspec.Hook, state []byte, stdout io.Writer,
if err := cmd.Process.Kill(); err != nil {
logrus.Errorf("Failed to kill pid %v", cmd.Process)
}
timer := time.NewTimer(postKillTimeout)
timer := time.NewTimer(options.PostKillTimeout)
defer timer.Stop()
select {
case <-timer.C:
err = fmt.Errorf("failed to reap process within %s of the kill signal", postKillTimeout)
err = fmt.Errorf("failed to reap process within %s of the kill signal", options.PostKillTimeout)
case err = <-exit:
}
return err, ctx.Err()

View File

@@ -21,19 +21,44 @@ var spewConfig = spew.ConfigState{
SortKeys: true,
}
type RuntimeConfigFilterOptions struct {
// The hooks to run
Hooks []spec.Hook
// The workdir to change when invoking the hook
Dir string
// The container config spec to pass into the hook processes and potentially get modified by them
Config *spec.Spec
// Timeout for waiting process killed
PostKillTimeout time.Duration
}
// RuntimeConfigFilter calls a series of hooks. But instead of
// passing container state on their standard input,
// RuntimeConfigFilter passes the proposed runtime configuration (and
// reads back a possibly-altered form from their standard output).
//
// Deprecated: Too many arguments, has been refactored and replaced by RuntimeConfigFilterWithOptions instead
func RuntimeConfigFilter(ctx context.Context, hooks []spec.Hook, config *spec.Spec, postKillTimeout time.Duration) (hookErr, err error) {
data, err := json.Marshal(config)
return RuntimeConfigFilterWithOptions(ctx, RuntimeConfigFilterOptions{
Hooks: hooks,
Config: config,
PostKillTimeout: postKillTimeout,
})
}
// RuntimeConfigFilterWithOptions calls a series of hooks. But instead of
// passing container state on their standard input,
// RuntimeConfigFilterWithOptions passes the proposed runtime configuration (and
// reads back a possibly-altered form from their standard output).
func RuntimeConfigFilterWithOptions(ctx context.Context, options RuntimeConfigFilterOptions) (hookErr, err error) {
data, err := json.Marshal(options.Config)
if err != nil {
return nil, err
}
for i, hook := range hooks {
for i, hook := range options.Hooks {
hook := hook
var stdout bytes.Buffer
hookErr, err = Run(ctx, &hook, data, &stdout, nil, postKillTimeout)
hookErr, err = RunWithOptions(ctx, RunOptions{Hook: &hook, Dir: options.Dir, State: data, Stdout: &stdout, PostKillTimeout: options.PostKillTimeout})
if err != nil {
return hookErr, err
}
@@ -46,8 +71,8 @@ func RuntimeConfigFilter(ctx context.Context, hooks []spec.Hook, config *spec.Sp
return nil, fmt.Errorf("unmarshal output from config-filter hook %d: %w", i, err)
}
if !reflect.DeepEqual(config, &newConfig) {
oldConfig := spewConfig.Sdump(config)
if !reflect.DeepEqual(options.Config, &newConfig) {
oldConfig := spewConfig.Sdump(options.Config)
newConfig := spewConfig.Sdump(&newConfig)
diff, err := difflib.GetUnifiedDiffString(difflib.UnifiedDiff{
A: difflib.SplitLines(oldConfig),
@@ -65,7 +90,7 @@ func RuntimeConfigFilter(ctx context.Context, hooks []spec.Hook, config *spec.Sp
}
}
*config = newConfig
*options.Config = newConfig
}
return nil, nil