vendor: bump runc to rc95

runc rc95 contains a fix for CVE-2021-30465.

runc rc94 provides fixes and improvements.

One notable change is cgroup manager's Set now accept Resources rather
than Cgroup (see https://github.com/opencontainers/runc/pull/2906).
Modify the code accordingly.

Also update runc dependencies (as hinted by hack/lint-depdendencies.sh):

        github.com/cilium/ebpf v0.5.0
        github.com/containerd/console v1.0.2
        github.com/coreos/go-systemd/v22 v22.3.1
        github.com/godbus/dbus/v5 v5.0.4
        github.com/moby/sys/mountinfo v0.4.1
        golang.org/x/sys v0.0.0-20210426230700-d19ff857e887
        github.com/google/go-cmp v0.5.4
        github.com/kr/pretty v0.2.1
        github.com/opencontainers/runtime-spec v1.0.3-0.20210326190908-1c3f411f0417

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

vendor/github.com/opencontainers/runc/libcontainer/utils/utils.go

@@ -3,12 +3,15 @@ package utils
 import (
 	"encoding/binary"
 	"encoding/json"
+	"fmt"
 	"io"
 	"os"
 	"path/filepath"
+	"strconv"
 	"strings"
 	"unsafe"
 
+	"github.com/cyphar/filepath-securejoin"
 	"golang.org/x/sys/unix"
 )
 
@@ -88,6 +91,57 @@ 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: %w", 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: %w", 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 {