runsc: fix panic for `runsc wait` on stopped container.

PiperOrigin-RevId: 203016694
Change-Id: Ic51ef754aa6d7d1b3b35491aff96a63d7992e122

2 files changed, 15 insertions, 0 deletions

diff --git a/runsc/container/container.go b/runsc/container/container.go
index 30323138a..c4e5bf9f6 100644
--- a/runsc/container/container.go
+++ b/runsc/container/container.go
@@ -352,6 +352,9 @@ func (c *Container) Pid() int {
 // Wait waits for the container to exit, and returns its WaitStatus.
 func (c *Container) Wait() (syscall.WaitStatus, error) {
 	log.Debugf("Wait on container %q", c.ID)
+	if c.Status == Stopped {
+		return 0, fmt.Errorf("container is stopped")
+	}
 	return c.Sandbox.Wait(c.ID)
 }
 
@@ -359,6 +362,9 @@ func (c *Container) Wait() (syscall.WaitStatus, error) {
 // returns its WaitStatus.
 func (c *Container) WaitRootPID(pid int32) (syscall.WaitStatus, error) {
 	log.Debugf("Wait on pid %d in sandbox %q", pid, c.Sandbox.ID)
+	if c.Status == Stopped {
+		return 0, fmt.Errorf("container is stopped")
+	}
 	return c.Sandbox.WaitPID(pid, c.Sandbox.ID)
 }
 
@@ -366,6 +372,9 @@ func (c *Container) WaitRootPID(pid int32) (syscall.WaitStatus, error) {
 // its WaitStatus.
 func (c *Container) WaitPID(pid int32) (syscall.WaitStatus, error) {
 	log.Debugf("Wait on pid %d in container %q", pid, c.ID)
+	if c.Status == Stopped {
+		return 0, fmt.Errorf("container is stopped")
+	}
 	return c.Sandbox.WaitPID(pid, c.ID)
 }
 
diff --git a/runsc/container/container_test.go b/runsc/container/container_test.go
index a6bb39c5d..d2f3cc14a 100644
--- a/runsc/container/container_test.go
+++ b/runsc/container/container_test.go
@@ -1211,6 +1211,9 @@ func TestMultiContainerWait(t *testing.T) {
 			} else if es := ws.ExitStatus(); es != 0 {
 				t.Errorf("process %q exited with non-zero status %d", strings.Join(containers[1].Spec.Process.Args, " "), es)
 			}
+			if _, err := containers[1].Wait(); err == nil {
+				t.Errorf("wait for stopped process %q should fail", strings.Join(containers[1].Spec.Process.Args, " "))
+			}
 
 			// After Wait returns, ensure that the root container is running and
 			// the child has finished.
@@ -1231,6 +1234,9 @@ func TestMultiContainerWait(t *testing.T) {
 			} else if es := ws.ExitStatus(); es != 0 {
 				t.Errorf("PID %d exited with non-zero status %d", pid, es)
 			}
+			if _, err := containers[0].WaitPID(pid); err == nil {
+				t.Errorf("wait for stopped PID %d should fail", pid)
+			}
 		}()
 	}