2 files changed, 28 insertions, 32 deletions

diff --git a/runsc/specutils/namespace.go b/runsc/specutils/namespace.go
index c7dd3051c..23001d67c 100644
--- a/runsc/specutils/namespace.go
+++ b/runsc/specutils/namespace.go
@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
+	"os/signal"
 	"path/filepath"
 	"runtime"
 	"syscall"
@@ -252,13 +253,27 @@ func MaybeRunAsRoot() error {
 		},
 		Credential:                 &syscall.Credential{Uid: 0, Gid: 0},
 		GidMappingsEnableSetgroups: false,
+
+		// Make sure child is killed when the parent terminates.
+		Pdeathsig: syscall.SIGKILL,
 	}
 
 	cmd.Env = os.Environ()
 	cmd.Stdin = os.Stdin
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
-	if err := cmd.Run(); err != nil {
+	if err := cmd.Start(); err != nil {
+		return fmt.Errorf("re-executing self: %w", err)
+	}
+	ch := make(chan os.Signal, 1)
+	signal.Notify(ch)
+	go func() {
+		for {
+			// Forward all signals to child process.
+			cmd.Process.Signal(<-ch)
+		}
+	}()
+	if err := cmd.Wait(); err != nil {
 		if exit, ok := err.(*exec.ExitError); ok {
 			if ws, ok := exit.Sys().(syscall.WaitStatus); ok {
 				os.Exit(ws.ExitStatus())
@@ -266,7 +281,7 @@ func MaybeRunAsRoot() error {
 			log.Warningf("No wait status provided, exiting with -1: %v", err)
 			os.Exit(-1)
 		}
-		return fmt.Errorf("re-executing self: %v", err)
+		return err
 	}
 	// Child completed with success.
 	os.Exit(0)
diff --git a/runsc/specutils/specutils.go b/runsc/specutils/specutils.go
index d3c2e4e78..f1fa573c5 100644
--- a/runsc/specutils/specutils.go
+++ b/runsc/specutils/specutils.go
@@ -92,6 +92,12 @@ func ValidateSpec(spec *specs.Spec) error {
 		log.Warningf("AppArmor profile %q is being ignored", spec.Process.ApparmorProfile)
 	}
 
+	// PR_SET_NO_NEW_PRIVS is assumed to always be set.
+	// See kernel.Task.updateCredsForExecLocked.
+	if !spec.Process.NoNewPrivileges {
+		log.Warningf("noNewPrivileges ignored. PR_SET_NO_NEW_PRIVS is assumed to always be set.")
+	}
+
 	// TODO(gvisor.dev/issue/510): Apply seccomp to application inside sandbox.
 	if spec.Linux != nil && spec.Linux.Seccomp != nil {
 		log.Warningf("Seccomp spec is being ignored")
@@ -438,36 +444,6 @@ func ContainsStr(strs []string, str string) bool {
 	return false
 }
 
-// Cleanup allows defers to be aborted when cleanup needs to happen
-// conditionally. Usage:
-// c := MakeCleanup(func() { f.Close() })
-// defer c.Clean() // any failure before release is called will close the file.
-// ...
-// c.Release() // on success, aborts closing the file and return it.
-// return f
-type Cleanup struct {
-	clean func()
-}
-
-// MakeCleanup creates a new Cleanup object.
-func MakeCleanup(f func()) Cleanup {
-	return Cleanup{clean: f}
-}
-
-// Clean calls the cleanup function.
-func (c *Cleanup) Clean() {
-	if c.clean != nil {
-		c.clean()
-		c.clean = nil
-	}
-}
-
-// Release releases the cleanup from its duties, i.e. cleanup function is not
-// called after this point.
-func (c *Cleanup) Release() {
-	c.clean = nil
-}
-
 // RetryEintr retries the function until an error different than EINTR is
 // returned.
 func RetryEintr(f func() (uintptr, uintptr, error)) (uintptr, uintptr, error) {
@@ -528,3 +504,8 @@ func EnvVar(env []string, name string) (string, bool) {
 	}
 	return "", false
 }
+
+// FaqErrorMsg returns an error message pointing to the FAQ.
+func FaqErrorMsg(anchor, msg string) string {
+	return fmt.Sprintf("%s; see https://gvisor.dev/faq#%s for more details", msg, anchor)
+}