.gitignore

@@ -1 +1 @@
-SOURCES/v1.1.12.tar.gz
+SOURCES/runc-dc9208a.tar.gz

.runc.metadata

@@ -1 +1 @@
-3fac650358578b8694012a44b1d5b156523c3402 SOURCES/v1.1.12.tar.gz
+32859590dea35b77eed012c388d97fc12fdfdb93 SOURCES/runc-dc9208a.tar.gz

SOURCES/0001-rootfs-add-mount-destination-validation.patch

@@ -0,0 +1,540 @@
+From 2dd156b190c02476191fc2522f9b0e0a1a098608 Mon Sep 17 00:00:00 2001
+From: Kir Kolyshkin <kolyshkin@gmail.com>
+Date: Mon, 17 May 2021 16:11:35 -0700
+Subject: [PATCH] rootfs: add mount destination validation
+
+This is a manual backport of fix for CVE-2021-30465 to runc-1.0.0-rc10
+(aka -rc90), upstream commit 84c14b43fa703db7 by Aleksa Sarai.
+
+Original description follows.
+
+----
+
+Because the target of a mount is inside a container (which may be a
+volume that is shared with another container), there exists a race
+condition where the target of the mount may change to a path containing
+a symlink after we have sanitised the path -- resulting in us
+inadvertently mounting the path outside of the container.
+
+This is not immediately useful because we are in a mount namespace with
+MS_SLAVE mount propagation applied to "/", so we cannot mount on top of
+host paths in the host namespace. However, if any subsequent mountpoints
+in the configuration use a subdirectory of that host path as a source,
+those subsequent mounts will use an attacker-controlled source path
+(resolved within the host rootfs) -- allowing the bind-mounting of "/"
+into the container.
+
+While arguably configuration issues like this are not entirely within
+runc's threat model, within the context of Kubernetes (and possibly
+other container managers that provide semi-arbitrary container creation
+privileges to untrusted users) this is a legitimate issue. Since we
+cannot block mounting from the host into the container, we need to block
+the first stage of this attack (mounting onto a path outside the
+container).
+
+The long-term plan to solve this would be to migrate to libpathrs, but
+as a stop-gap we implement libpathrs-like path verification through
+readlink(/proc/self/fd/$n) and then do mount operations through the
+procfd once it's been verified to be inside the container. The target
+could move after we've checked it, but if it is inside the container
+then we can assume that it is safe for the same reason that libpathrs
+operations would be safe.
+
+A slight wrinkle is the "copyup" functionality we provide for tmpfs,
+which is the only case where we want to do a mount on the host
+filesystem. To facilitate this, I split out the copy-up functionality
+entirely so that the logic isn't interspersed with the regular tmpfs
+logic. In addition, all dependencies on m.Destination being overwritten
+have been removed since that pattern was just begging to be a source of
+more mount-target bugs (we do still have to modify m.Destination for
+tmpfs-copyup but we only do it temporarily).
+
+Fixes: CVE-2021-30465
+Reported-by: Etienne Champetier <champetier.etienne@gmail.com>
+Co-authored-by: Noah Meyerhans <nmeyerha@amazon.com>
+Reviewed-by: Samuel Karp <skarp@amazon.com>
+Reviewed-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
+Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
+
+Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
+---
+ libcontainer/rootfs_linux.go     | 225 ++++++++++++++++---------------
+ libcontainer/utils/utils.go      |  54 ++++++++
+ libcontainer/utils/utils_test.go |  35 +++++
+ 3 files changed, 204 insertions(+), 110 deletions(-)
+
+diff --git a/libcontainer/rootfs_linux.go b/libcontainer/rootfs_linux.go
+index 106c4c2b..fe9afe48 100644
+--- a/libcontainer/rootfs_linux.go
++++ b/libcontainer/rootfs_linux.go
+@@ -19,8 +19,9 @@ import (
+ 	"github.com/opencontainers/runc/libcontainer/configs"
+ 	"github.com/opencontainers/runc/libcontainer/mount"
+ 	"github.com/opencontainers/runc/libcontainer/system"
+-	libcontainerUtils "github.com/opencontainers/runc/libcontainer/utils"
++	"github.com/opencontainers/runc/libcontainer/utils"
+ 	"github.com/opencontainers/selinux/go-selinux/label"
++	"github.com/sirupsen/logrus"
+ 
+ 	"golang.org/x/sys/unix"
+ )
+@@ -30,7 +31,7 @@ const defaultMountFlags = unix.MS_NOEXEC | unix.MS_NOSUID | unix.MS_NODEV
+ // needsSetupDev returns true if /dev needs to be set up.
+ func needsSetupDev(config *configs.Config) bool {
+ 	for _, m := range config.Mounts {
+-		if m.Device == "bind" && libcontainerUtils.CleanPath(m.Destination) == "/dev" {
++		if m.Device == "bind" && utils.CleanPath(m.Destination) == "/dev" {
+ 			return false
+ 		}
+ 	}
+@@ -131,7 +132,7 @@ func prepareRootfs(pipe io.ReadWriter, iConfig *initConfig) (err error) {
+ func finalizeRootfs(config *configs.Config) (err error) {
+ 	// remount dev as ro if specified
+ 	for _, m := range config.Mounts {
+-		if libcontainerUtils.CleanPath(m.Destination) == "/dev" {
++		if utils.CleanPath(m.Destination) == "/dev" {
+ 			if m.Flags&unix.MS_RDONLY == unix.MS_RDONLY {
+ 				if err := remountReadonly(m); err != nil {
+ 					return newSystemErrorWithCausef(err, "remounting %q as readonly", m.Destination)
+@@ -200,8 +201,6 @@ func prepareBindMount(m *configs.Mount, rootfs string) error {
+ 	if err := checkProcMount(rootfs, dest, m.Source); err != nil {
+ 		return err
+ 	}
+-	// update the mount with the correct dest after symlinks are resolved.
+-	m.Destination = dest
+ 	if err := createIfNotExists(dest, stat.IsDir()); err != nil {
+ 		return err
+ 	}
+@@ -238,18 +237,21 @@ func mountCgroupV1(m *configs.Mount, rootfs, mountLabel string, enableCgroupns b
+ 			if err := os.MkdirAll(subsystemPath, 0755); err != nil {
+ 				return err
+ 			}
+-			flags := defaultMountFlags
+-			if m.Flags&unix.MS_RDONLY != 0 {
+-				flags = flags | unix.MS_RDONLY
+-			}
+-			cgroupmount := &configs.Mount{
+-				Source:      "cgroup",
+-				Device:      "cgroup",
+-				Destination: subsystemPath,
+-				Flags:       flags,
+-				Data:        filepath.Base(subsystemPath),
+-			}
+-			if err := mountNewCgroup(cgroupmount); err != nil {
++			if err := utils.WithProcfd(rootfs, b.Destination, func(procfd string) error {
++				flags := defaultMountFlags
++				if m.Flags&unix.MS_RDONLY != 0 {
++					flags = flags | unix.MS_RDONLY
++				}
++				var (
++					source = "cgroup"
++					data   = filepath.Base(subsystemPath)
++				)
++				if data == "systemd" {
++					data = cgroups.CgroupNamePrefix + data
++					source = "systemd"
++				}
++				return unix.Mount(source, procfd, "cgroup", uintptr(flags), data)
++			}); err != nil {
+ 				return err
+ 			}
+ 		} else {
+@@ -279,22 +281,67 @@ func mountCgroupV2(m *configs.Mount, rootfs, mountLabel string, enableCgroupns b
+ 	if err := os.MkdirAll(cgroupPath, 0755); err != nil {
+ 		return err
+ 	}
+-	if err := unix.Mount(m.Source, cgroupPath, "cgroup2", uintptr(m.Flags), m.Data); err != nil {
+-		// when we are in UserNS but CgroupNS is not unshared, we cannot mount cgroup2 (#2158)
+-		if err == unix.EPERM || err == unix.EBUSY {
+-			return unix.Mount("/sys/fs/cgroup", cgroupPath, "", uintptr(m.Flags)|unix.MS_BIND, "")
++	return utils.WithProcfd(rootfs, m.Destination, func(procfd string) error {
++		if err := unix.Mount(m.Source, procfd, "cgroup2", uintptr(m.Flags), m.Data); err != nil {
++			// when we are in UserNS but CgroupNS is not unshared, we cannot mount cgroup2 (#2158)
++			if err == unix.EPERM || err == unix.EBUSY {
++				return unix.Mount("/sys/fs/cgroup", procfd, "", uintptr(m.Flags)|unix.MS_BIND, "")
++			}
++			return err
+ 		}
++		return nil
++	})
++}
++
++func doTmpfsCopyUp(m *configs.Mount, rootfs, mountLabel string) (Err error) {
++	// Set up a scratch dir for the tmpfs on the host.
++	tmpdir, err := prepareTmp("/tmp")
++	if err != nil {
++		return newSystemErrorWithCause(err, "tmpcopyup: failed to setup tmpdir")
++	}
++	defer cleanupTmp(tmpdir)
++	tmpDir, err := ioutil.TempDir(tmpdir, "runctmpdir")
++	if err != nil {
++		return newSystemErrorWithCause(err, "tmpcopyup: failed to create tmpdir")
++	}
++	defer os.RemoveAll(tmpDir)
++
++	// Configure the *host* tmpdir as if it's the container mount. We change
++	// m.Destination since we are going to mount *on the host*.
++	oldDest := m.Destination
++	m.Destination = tmpDir
++	err = mountPropagate(m, "/", mountLabel)
++	m.Destination = oldDest
++	if err != nil {
+ 		return err
+ 	}
+-	return nil
++	defer func() {
++		if Err != nil {
++			if err := unix.Unmount(tmpDir, unix.MNT_DETACH); err != nil {
++				logrus.Warnf("tmpcopyup: failed to unmount tmpdir on error: %v", err)
++			}
++		}
++	}()
++
++	return utils.WithProcfd(rootfs, m.Destination, func(procfd string) (Err error) {
++		// Copy the container data to the host tmpdir. We append "/" to force
++		// CopyDirectory to resolve the symlink rather than trying to copy the
++		// symlink itself.
++		if err := fileutils.CopyDirectory(procfd+"/", tmpDir); err != nil {
++			return fmt.Errorf("tmpcopyup: failed to copy %s to %s (%s): %v", m.Destination, procfd, tmpDir, err)
++		}
++		// Now move the mount into the container.
++		if err := unix.Mount(tmpDir, procfd, "", unix.MS_MOVE, ""); err != nil {
++			return fmt.Errorf("tmpcopyup: failed to move mount %s to %s (%s): %v", tmpDir, procfd, m.Destination, err)
++		}
++		return nil
++	})
+ }
+ 
+ func mountToRootfs(m *configs.Mount, rootfs, mountLabel string, enableCgroupns bool) error {
+-	var (
+-		dest = m.Destination
+-	)
+-	if !strings.HasPrefix(dest, rootfs) {
+-		dest = filepath.Join(rootfs, dest)
++	dest, err := securejoin.SecureJoin(rootfs, m.Destination)
++	if err != nil {
++		return err
+ 	}
+ 
+ 	switch m.Device {
+@@ -329,46 +376,21 @@ func mountToRootfs(m *configs.Mount, rootfs, mountLabel string, enableCgroupns b
+ 		}
+ 		return nil
+ 	case "tmpfs":
+-		copyUp := m.Extensions&configs.EXT_COPYUP == configs.EXT_COPYUP
+-		tmpDir := ""
+ 		stat, err := os.Stat(dest)
+ 		if err != nil {
+ 			if err := os.MkdirAll(dest, 0755); err != nil {
+ 				return err
+ 			}
+ 		}
+-		if copyUp {
+-			tmpdir, err := prepareTmp("/tmp")
+-			if err != nil {
+-				return newSystemErrorWithCause(err, "tmpcopyup: failed to setup tmpdir")
+-			}
+-			defer cleanupTmp(tmpdir)
+-			tmpDir, err = ioutil.TempDir(tmpdir, "runctmpdir")
+-			if err != nil {
+-				return newSystemErrorWithCause(err, "tmpcopyup: failed to create tmpdir")
+-			}
+-			defer os.RemoveAll(tmpDir)
+-			m.Destination = tmpDir
++
++		if m.Extensions&configs.EXT_COPYUP == configs.EXT_COPYUP {
++			err = doTmpfsCopyUp(m, rootfs, mountLabel)
++		} else {
++			err = mountPropagate(m, rootfs, mountLabel)
+ 		}
+-		if err := mountPropagate(m, rootfs, mountLabel); err != nil {
++		if err != nil {
+ 			return err
+ 		}
+-		if copyUp {
+-			if err := fileutils.CopyDirectory(dest, tmpDir); err != nil {
+-				errMsg := fmt.Errorf("tmpcopyup: failed to copy %s to %s: %v", dest, tmpDir, err)
+-				if err1 := unix.Unmount(tmpDir, unix.MNT_DETACH); err1 != nil {
+-					return newSystemErrorWithCausef(err1, "tmpcopyup: %v: failed to unmount", errMsg)
+-				}
+-				return errMsg
+-			}
+-			if err := unix.Mount(tmpDir, dest, "", unix.MS_MOVE, ""); err != nil {
+-				errMsg := fmt.Errorf("tmpcopyup: failed to move mount %s to %s: %v", tmpDir, dest, err)
+-				if err1 := unix.Unmount(tmpDir, unix.MNT_DETACH); err1 != nil {
+-					return newSystemErrorWithCausef(err1, "tmpcopyup: %v: failed to unmount", errMsg)
+-				}
+-				return errMsg
+-			}
+-		}
+ 		if stat != nil {
+ 			if err = os.Chmod(dest, stat.Mode()); err != nil {
+ 				return err
+@@ -424,19 +446,9 @@ func mountToRootfs(m *configs.Mount, rootfs, mountLabel string, enableCgroupns b
+ 			}
+ 		}
+ 	default:
+-		// ensure that the destination of the mount is resolved of symlinks at mount time because
+-		// any previous mounts can invalidate the next mount's destination.
+-		// this can happen when a user specifies mounts within other mounts to cause breakouts or other
+-		// evil stuff to try to escape the container's rootfs.
+-		var err error
+-		if dest, err = securejoin.SecureJoin(rootfs, m.Destination); err != nil {
+-			return err
+-		}
+ 		if err := checkProcMount(rootfs, dest, m.Source); err != nil {
+ 			return err
+ 		}
+-		// update the mount with the correct dest after symlinks are resolved.
+-		m.Destination = dest
+ 		if err := os.MkdirAll(dest, 0755); err != nil {
+ 			return err
+ 		}
+@@ -611,7 +623,7 @@ func createDevices(config *configs.Config) error {
+ 	return nil
+ }
+ 
+-func bindMountDeviceNode(dest string, node *configs.Device) error {
++func bindMountDeviceNode(rootfs, dest string, node *configs.Device) error {
+ 	f, err := os.Create(dest)
+ 	if err != nil && !os.IsExist(err) {
+ 		return err
+@@ -619,24 +631,29 @@ func bindMountDeviceNode(dest string, node *configs.Device) error {
+ 	if f != nil {
+ 		f.Close()
+ 	}
+-	return unix.Mount(node.Path, dest, "bind", unix.MS_BIND, "")
++	return utils.WithProcfd(rootfs, dest, func(procfd string) error {
++		return unix.Mount(node.Path, procfd, "bind", unix.MS_BIND, "")
++	})
+ }
+ 
+ // Creates the device node in the rootfs of the container.
+ func createDeviceNode(rootfs string, node *configs.Device, bind bool) error {
+-	dest := filepath.Join(rootfs, node.Path)
++	dest, err := securejoin.SecureJoin(rootfs, node.Path)
++	if err != nil {
++		return err
++	}
+ 	if err := os.MkdirAll(filepath.Dir(dest), 0755); err != nil {
+ 		return err
+ 	}
+ 
+ 	if bind {
+-		return bindMountDeviceNode(dest, node)
++		return bindMountDeviceNode(rootfs, dest, node)
+ 	}
+ 	if err := mknodDevice(dest, node); err != nil {
+ 		if os.IsExist(err) {
+ 			return nil
+ 		} else if os.IsPermission(err) {
+-			return bindMountDeviceNode(dest, node)
++			return bindMountDeviceNode(rootfs, dest, node)
+ 		}
+ 		return err
+ 	}
+@@ -955,55 +972,43 @@ func writeSystemProperty(key, value string) error {
+ }
+ 
+ func remount(m *configs.Mount, rootfs string) error {
+-	var (
+-		dest = m.Destination
+-	)
+-	if !strings.HasPrefix(dest, rootfs) {
+-		dest = filepath.Join(rootfs, dest)
+-	}
+-	return unix.Mount(m.Source, dest, m.Device, uintptr(m.Flags|unix.MS_REMOUNT), "")
++	return utils.WithProcfd(rootfs, m.Destination, func(procfd string) error {
++		return unix.Mount(m.Source, procfd, m.Device, uintptr(m.Flags|unix.MS_REMOUNT), "")
++	})
+ }
+ 
+ // Do the mount operation followed by additional mounts required to take care
+-// of propagation flags.
++// of propagation flags.  This will always be scoped inside the container rootfs.
+ func mountPropagate(m *configs.Mount, rootfs string, mountLabel string) error {
+ 	var (
+-		dest  = m.Destination
+ 		data  = label.FormatMountLabel(m.Data, mountLabel)
+ 		flags = m.Flags
+ 	)
+-	if libcontainerUtils.CleanPath(dest) == "/dev" {
++	if utils.CleanPath(m.Destination) == "/dev" {
+ 		flags &= ^unix.MS_RDONLY
+ 	}
+ 
+-	copyUp := m.Extensions&configs.EXT_COPYUP == configs.EXT_COPYUP
+-	if !(copyUp || strings.HasPrefix(dest, rootfs)) {
+-		dest = filepath.Join(rootfs, dest)
+-	}
+-
+-	if err := unix.Mount(m.Source, dest, m.Device, uintptr(flags), data); err != nil {
+-		return err
+-	}
+-
+-	for _, pflag := range m.PropagationFlags {
+-		if err := unix.Mount("", dest, "", uintptr(pflag), ""); err != nil {
+-			return err
++	// Because the destination is inside a container path which might be
++	// mutating underneath us, we verify that we are actually going to mount
++	// inside the container with WithProcfd() -- mounting through a procfd
++	// mounts on the target.
++	if err := utils.WithProcfd(rootfs, m.Destination, func(procfd string) error {
++		return unix.Mount(m.Source, procfd, m.Device, uintptr(flags), data)
++	}); err != nil {
++		return fmt.Errorf("mount through procfd: %v", err)
++	}
++	// We have to apply mount propagation flags in a separate WithProcfd() call
++	// because the previous call invalidates the passed procfd -- the mount
++	// target needs to be re-opened.
++	if err := utils.WithProcfd(rootfs, m.Destination, func(procfd string) error {
++		for _, pflag := range m.PropagationFlags {
++			if err := unix.Mount("", procfd, "", uintptr(pflag), ""); err != nil {
++				return err
++			}
+ 		}
+-	}
+-	return nil
+-}
+-
+-func mountNewCgroup(m *configs.Mount) error {
+-	var (
+-		data   = m.Data
+-		source = m.Source
+-	)
+-	if data == "systemd" {
+-		data = cgroups.CgroupNamePrefix + data
+-		source = "systemd"
+-	}
+-	if err := unix.Mount(source, m.Destination, m.Device, uintptr(m.Flags), data); err != nil {
+-		return err
++		return nil
++	}); err != nil {
++		return fmt.Errorf("change mount propagation through procfd: %v", err)
+ 	}
+ 	return nil
+ }
+diff --git a/libcontainer/utils/utils.go b/libcontainer/utils/utils.go
+index 40ccfaa1..c1418ef9 100644
+--- a/libcontainer/utils/utils.go
++++ b/libcontainer/utils/utils.go
+@@ -2,12 +2,15 @@ package utils
+ 
+ import (
+ 	"encoding/json"
++	"fmt"
+ 	"io"
+ 	"os"
+ 	"path/filepath"
++	"strconv"
+ 	"strings"
+ 	"unsafe"
+ 
++	securejoin "github.com/cyphar/filepath-securejoin"
+ 	"golang.org/x/sys/unix"
+ )
+ 
+@@ -73,6 +76,57 @@ func CleanPath(path string) string {
+ 	return filepath.Clean(path)
+ }
+ 
++// stripRoot returns the passed path, stripping the root path if it was
++// (lexicially) inside it. Note that both passed paths will always be treated
++// as absolute, and the returned path will also always be absolute. In
++// addition, the paths are cleaned before stripping the root.
++func stripRoot(root, path string) string {
++	// Make the paths clean and absolute.
++	root, path = CleanPath("/"+root), CleanPath("/"+path)
++	switch {
++	case path == root:
++		path = "/"
++	case root == "/":
++		// do nothing
++	case strings.HasPrefix(path, root+"/"):
++		path = strings.TrimPrefix(path, root+"/")
++	}
++	return CleanPath("/" + path)
++}
++
++// WithProcfd runs the passed closure with a procfd path (/proc/self/fd/...)
++// corresponding to the unsafePath resolved within the root. Before passing the
++// fd, this path is verified to have been inside the root -- so operating on it
++// through the passed fdpath should be safe. Do not access this path through
++// the original path strings, and do not attempt to use the pathname outside of
++// the passed closure (the file handle will be freed once the closure returns).
++func WithProcfd(root, unsafePath string, fn func(procfd string) error) error {
++	// Remove the root then forcefully resolve inside the root.
++	unsafePath = stripRoot(root, unsafePath)
++	path, err := securejoin.SecureJoin(root, unsafePath)
++	if err != nil {
++		return fmt.Errorf("resolving path inside rootfs failed: %v", err)
++	}
++
++	// Open the target path.
++	fh, err := os.OpenFile(path, unix.O_PATH|unix.O_CLOEXEC, 0)
++	if err != nil {
++		return fmt.Errorf("open o_path procfd: %v", err)
++	}
++	defer fh.Close()
++
++	// Double-check the path is the one we expected.
++	procfd := "/proc/self/fd/" + strconv.Itoa(int(fh.Fd()))
++	if realpath, err := os.Readlink(procfd); err != nil {
++		return fmt.Errorf("procfd verification failed: %v", err)
++	} else if realpath != path {
++		return fmt.Errorf("possibly malicious path detected -- refusing to operate on %s", realpath)
++	}
++
++	// Run the closure.
++	return fn(procfd)
++}
++
+ // SearchLabels searches a list of key-value pairs for the provided key and
+ // returns the corresponding value. The pairs must be separated with '='.
+ func SearchLabels(labels []string, query string) string {
+diff --git a/libcontainer/utils/utils_test.go b/libcontainer/utils/utils_test.go
+index 395eedcf..5b80cac6 100644
+--- a/libcontainer/utils/utils_test.go
++++ b/libcontainer/utils/utils_test.go
+@@ -140,3 +140,38 @@ func TestCleanPath(t *testing.T) {
+ 		t.Errorf("expected to receive '/foo' and received %s", path)
+ 	}
+ }
++
++func TestStripRoot(t *testing.T) {
++	for _, test := range []struct {
++		root, path, out string
++	}{
++		// Works with multiple components.
++		{"/a/b", "/a/b/c", "/c"},
++		{"/hello/world", "/hello/world/the/quick-brown/fox", "/the/quick-brown/fox"},
++		// '/' must be a no-op.
++		{"/", "/a/b/c", "/a/b/c"},
++		// Must be the correct order.
++		{"/a/b", "/a/c/b", "/a/c/b"},
++		// Must be at start.
++		{"/abc/def", "/foo/abc/def/bar", "/foo/abc/def/bar"},
++		// Must be a lexical parent.
++		{"/foo/bar", "/foo/barSAMECOMPONENT", "/foo/barSAMECOMPONENT"},
++		// Must only strip the root once.
++		{"/foo/bar", "/foo/bar/foo/bar/baz", "/foo/bar/baz"},
++		// Deal with .. in a fairly sane way.
++		{"/foo/bar", "/foo/bar/../baz", "/foo/baz"},
++		{"/foo/bar", "../../../../../../foo/bar/baz", "/baz"},
++		{"/foo/bar", "/../../../../../../foo/bar/baz", "/baz"},
++		{"/foo/bar/../baz", "/foo/baz/bar", "/bar"},
++		{"/foo/bar/../baz", "/foo/baz/../bar/../baz/./foo", "/foo"},
++		// All paths are made absolute before stripping.
++		{"foo/bar", "/foo/bar/baz/bee", "/baz/bee"},
++		{"/foo/bar", "foo/bar/baz/beef", "/baz/beef"},
++		{"foo/bar", "foo/bar/baz/beets", "/baz/beets"},
++	} {
++		got := stripRoot(test.root, test.path)
++		if got != test.out {
++			t.Errorf("stripRoot(%q, %q) -- got %q, expected %q", test.root, test.path, got, test.out)
++		}
++	}
++}
+-- 
+2.31.1
+

SOURCES/1807.patch

@@ -0,0 +1,278 @@
+From 3d99c51e1b38a440804a55c9f314f62cc50b8902 Mon Sep 17 00:00:00 2001
+From: Giuseppe Scrivano <gscrivan@redhat.com>
+Date: Fri, 25 May 2018 18:04:06 +0200
+Subject: [PATCH] sd-notify: do not hang when NOTIFY_SOCKET is used with create
+
+if NOTIFY_SOCKET is used, do not block the main runc process waiting
+for events on the notify socket.  Bind mount the parent directory of
+the notify socket, so that "start" can create the socket and it is
+still accessible from the container.
+
+Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
+---
+ notify_socket.go | 112 ++++++++++++++++++++++++++++++++++-------------
+ signals.go       |   4 +-
+ start.go         |  13 +++++-
+ utils_linux.go   |  12 ++++-
+ 4 files changed, 105 insertions(+), 36 deletions(-)
+
+diff --git a/notify_socket.go b/notify_socket.go
+index e7453c62..d961453a 100644
+--- a/notify_socket.go
++++ b/notify_socket.go
+@@ -7,11 +7,13 @@ import (
+ 	"fmt"
+ 	"net"
+ 	"os"
++	"path"
+ 	"path/filepath"
++	"strconv"
++	"time"
+ 
++	"github.com/opencontainers/runc/libcontainer"
+ 	"github.com/opencontainers/runtime-spec/specs-go"
+-
+-	"github.com/sirupsen/logrus"
+ 	"github.com/urfave/cli"
+ )
+ 
+@@ -27,12 +29,12 @@ func newNotifySocket(context *cli.Context, notifySocketHost string, id string) *
+ 	}
+ 
+ 	root := filepath.Join(context.GlobalString("root"), id)
+-	path := filepath.Join(root, "notify.sock")
++	socketPath := filepath.Join(root, "notify", "notify.sock")
+ 
+ 	notifySocket := &notifySocket{
+ 		socket:     nil,
+ 		host:       notifySocketHost,
+-		socketPath: path,
++		socketPath: socketPath,
+ 	}
+ 
+ 	return notifySocket
+@@ -44,13 +46,19 @@ func (s *notifySocket) Close() error {
+ 
+ // If systemd is supporting sd_notify protocol, this function will add support
+ // for sd_notify protocol from within the container.
+-func (s *notifySocket) setupSpec(context *cli.Context, spec *specs.Spec) {
+-	mount := specs.Mount{Destination: s.host, Source: s.socketPath, Options: []string{"bind"}}
++func (s *notifySocket) setupSpec(context *cli.Context, spec *specs.Spec) error {
++	pathInContainer := filepath.Join("/run/notify", path.Base(s.socketPath))
++	mount := specs.Mount{
++		Destination: path.Dir(pathInContainer),
++		Source:      path.Dir(s.socketPath),
++		Options:     []string{"bind", "nosuid", "noexec", "nodev", "ro"},
++	}
+ 	spec.Mounts = append(spec.Mounts, mount)
+-	spec.Process.Env = append(spec.Process.Env, fmt.Sprintf("NOTIFY_SOCKET=%s", s.host))
++	spec.Process.Env = append(spec.Process.Env, fmt.Sprintf("NOTIFY_SOCKET=%s", pathInContainer))
++	return nil
+ }
+ 
+-func (s *notifySocket) setupSocket() error {
++func (s *notifySocket) bindSocket() error {
+ 	addr := net.UnixAddr{
+ 		Name: s.socketPath,
+ 		Net:  "unixgram",
+@@ -71,45 +79,89 @@ func (s *notifySocket) setupSocket() error {
+ 	return nil
+ }
+ 
+-// pid1 must be set only with -d, as it is used to set the new process as the main process
+-// for the service in systemd
+-func (s *notifySocket) run(pid1 int) {
+-	buf := make([]byte, 512)
+-	notifySocketHostAddr := net.UnixAddr{Name: s.host, Net: "unixgram"}
++func (s *notifySocket) setupSocketDirectory() error {
++	return os.Mkdir(path.Dir(s.socketPath), 0755)
++}
++
++func notifySocketStart(context *cli.Context, notifySocketHost, id string) (*notifySocket, error) {
++	notifySocket := newNotifySocket(context, notifySocketHost, id)
++	if notifySocket == nil {
++		return nil, nil
++	}
++
++	if err := notifySocket.bindSocket(); err != nil {
++		return nil, err
++	}
++	return notifySocket, nil
++}
++
++func (n *notifySocket) waitForContainer(container libcontainer.Container) error {
++	s, err := container.State()
++	if err != nil {
++		return err
++	}
++	return n.run(s.InitProcessPid)
++}
++
++func (n *notifySocket) run(pid1 int) error {
++	if n.socket == nil {
++		return nil
++	}
++	notifySocketHostAddr := net.UnixAddr{Name: n.host, Net: "unixgram"}
+ 	client, err := net.DialUnix("unixgram", nil, &notifySocketHostAddr)
+ 	if err != nil {
+-		logrus.Error(err)
+-		return
++		return err
+ 	}
+-	for {
+-		r, err := s.socket.Read(buf)
+-		if err != nil {
+-			break
++
++	ticker := time.NewTicker(time.Millisecond * 100)
++	defer ticker.Stop()
++
++	fileChan := make(chan []byte)
++	go func() {
++		for {
++			buf := make([]byte, 512)
++			r, err := n.socket.Read(buf)
++			if err != nil {
++				return
++			}
++			got := buf[0:r]
++			if !bytes.HasPrefix(got, []byte("READY=")) {
++				continue
++			}
++			fileChan <- got
++			return
+ 		}
+-		var out bytes.Buffer
+-		for _, line := range bytes.Split(buf[0:r], []byte{'\n'}) {
+-			if bytes.HasPrefix(line, []byte("READY=")) {
++	}()
++
++	for {
++		select {
++		case <-ticker.C:
++			_, err := os.Stat(filepath.Join("/proc", strconv.Itoa(pid1)))
++			if err != nil {
++				return nil
++			}
++		case b := <-fileChan:
++			for _, line := range bytes.Split(b, []byte{'\n'}) {
++				var out bytes.Buffer
+ 				_, err = out.Write(line)
+ 				if err != nil {
+-					return
++					return err
+ 				}
+ 
+ 				_, err = out.Write([]byte{'\n'})
+ 				if err != nil {
+-					return
++					return err
+ 				}
+ 
+ 				_, err = client.Write(out.Bytes())
+ 				if err != nil {
+-					return
++					return err
+ 				}
+ 
+ 				// now we can inform systemd to use pid1 as the pid to monitor
+-				if pid1 > 0 {
+-					newPid := fmt.Sprintf("MAINPID=%d\n", pid1)
+-					client.Write([]byte(newPid))
+-				}
+-				return
++				newPid := fmt.Sprintf("MAINPID=%d\n", pid1)
++				client.Write([]byte(newPid))
++				return nil
+ 			}
+ 		}
+ 	}
+diff --git a/signals.go b/signals.go
+index b67f65a0..dd25e094 100644
+--- a/signals.go
++++ b/signals.go
+@@ -70,6 +70,7 @@ func (h *signalHandler) forward(process *libcontainer.Process, tty *tty, detach
+ 			h.notifySocket.run(pid1)
+ 			return 0, nil
+ 		}
++		h.notifySocket.run(os.Getpid())
+ 		go h.notifySocket.run(0)
+ 	}
+ 
+@@ -97,9 +98,6 @@ func (h *signalHandler) forward(process *libcontainer.Process, tty *tty, detach
+ 					// status because we must ensure that any of the go specific process
+ 					// fun such as flushing pipes are complete before we return.
+ 					process.Wait()
+-					if h.notifySocket != nil {
+-						h.notifySocket.Close()
+-					}
+ 					return e.status, nil
+ 				}
+ 			}
+diff --git a/start.go b/start.go
+index 2bb698b2..3a1769a4 100644
+--- a/start.go
++++ b/start.go
+@@ -3,6 +3,7 @@ package main
+ import (
+ 	"errors"
+ 	"fmt"
++	"os"
+ 
+ 	"github.com/opencontainers/runc/libcontainer"
+ 	"github.com/urfave/cli"
+@@ -31,7 +32,17 @@ your host.`,
+ 		}
+ 		switch status {
+ 		case libcontainer.Created:
+-			return container.Exec()
++			notifySocket, err := notifySocketStart(context, os.Getenv("NOTIFY_SOCKET"), container.ID())
++			if err != nil {
++				return err
++			}
++			if err := container.Exec(); err != nil {
++				return err
++			}
++			if notifySocket != nil {
++				return notifySocket.waitForContainer(container)
++			}
++			return nil
+ 		case libcontainer.Stopped:
+ 			return errors.New("cannot start a container that has stopped")
+ 		case libcontainer.Running:
+diff --git a/utils_linux.go b/utils_linux.go
+index 984e6b0f..46c26246 100644
+--- a/utils_linux.go
++++ b/utils_linux.go
+@@ -408,7 +408,9 @@ func startContainer(context *cli.Context, spec *specs.Spec, action CtAct, criuOp
+ 
+ 	notifySocket := newNotifySocket(context, os.Getenv("NOTIFY_SOCKET"), id)
+ 	if notifySocket != nil {
+-		notifySocket.setupSpec(context, spec)
++		if err := notifySocket.setupSpec(context, spec); err != nil {
++			return -1, err
++		}
+ 	}
+ 
+ 	container, err := createContainer(context, id, spec)
+@@ -417,10 +419,16 @@ func startContainer(context *cli.Context, spec *specs.Spec, action CtAct, criuOp
+ 	}
+ 
+ 	if notifySocket != nil {
+-		err := notifySocket.setupSocket()
++		err := notifySocket.setupSocketDirectory()
+ 		if err != nil {
+ 			return -1, err
+ 		}
++		if action == CT_ACT_RUN {
++			err := notifySocket.bindSocket()
++			if err != nil {
++				return -1, err
++			}
++		}
+ 	}
+ 
+ 	// Support on-demand socket activation by passing file descriptors into the container init process.
+-- 
+2.21.0
+