diff --git a/pkg/sentry/platform/systrap/shared_context.go b/pkg/sentry/platform/systrap/shared_context.go
index a3e900aec0..86ef064aba 100644
--- a/pkg/sentry/platform/systrap/shared_context.go
+++ b/pkg/sentry/platform/systrap/shared_context.go
@@ -129,11 +129,12 @@ func (sc *sharedContext) NotifyInterrupt() {
 	if sc.threadID() == invalidThreadID {
 		return
 	}
-	sc.subprocess.sysmsgThreadsMu.Lock()
-	defer sc.subprocess.sysmsgThreadsMu.Unlock()
+	s := sc.subprocess
+	s.sysmsgThreadsMu.Lock()
+	defer s.sysmsgThreadsMu.Unlock()
 
 	threadID := atomic.LoadUint32(&sc.shared.ThreadID)
-	sysmsgThread, ok := sc.subprocess.sysmsgThreads[threadID]
+	sysmsgThread, ok := s.sysmsgThreads[threadID]
 	if !ok {
 		// This is either an invalidThreadID or another garbage value; either way we
 		// don't know which thread to interrupt; best we can do is mark the context.
@@ -142,7 +143,18 @@ func (sc *sharedContext) NotifyInterrupt() {
 
 	t := sysmsgThread.thread
 	if e := hostsyscall.RawSyscallErrno(unix.SYS_TGKILL, uintptr(t.tgid), uintptr(t.tid), uintptr(platform.SignalInterrupt)); e != 0 {
-		panic(fmt.Sprintf("failed to interrupt the child process %d: %v", t.tid, e))
+		if e == unix.ESRCH { // Stub thread already killed?
+			s.dead.Store(true)
+			if !sc.shared.State.CompareAndSwap(sysmsg.ContextStateNone, sysmsg.ContextStateUnexpectedDeath) {
+				s.syscallThread.thread.Warningf("failed to set context state to ContextStateUnexpectedDeath; context state was %v", sc.state())
+			}
+			s.syscallThreadMu.Lock()
+			defer s.syscallThreadMu.Unlock()
+			s.syscallThread.thread.Warningf("Cannot interrupt stub thread %sas it no longer exists; killing syscall thread.", *t.loadLogPrefix())
+			s.syscallThread.thread.kill()
+		} else {
+			panic(fmt.Sprintf("failed to interrupt the child process %d: %v", t.tid, e))
+		}
 	}
 }
 
diff --git a/pkg/sentry/platform/systrap/subprocess.go b/pkg/sentry/platform/systrap/subprocess.go
index a3182b73c0..e9d5b63265 100644
--- a/pkg/sentry/platform/systrap/subprocess.go
+++ b/pkg/sentry/platform/systrap/subprocess.go
@@ -685,7 +685,7 @@ func (t *thread) wait(outcome waitOutcome) unix.Signal {
 	}
 }
 
-// kill kills the thread;
+// kill kills the thread.
 func (t *thread) kill() {
 	unix.Tgkill(int(t.tgid), int(t.tid), unix.Signal(unix.SIGKILL))
 }
@@ -863,13 +863,17 @@ func (s *subprocess) switchToApp(c *platformContext, ac *arch.Context64) (isSysc
 		ctxState = sysmsg.ContextStateSyscall
 		shouldPatchSyscall = true
 	}
-
 	if ctxState == sysmsg.ContextStateSyscall || ctxState == sysmsg.ContextStateSyscallTrap {
 		if maybePatchSignalInfo(regs, &c.signalInfo) {
 			return false, false, hostarch.Execute, nil
 		}
 		updateSyscallRegs(regs)
 		return true, shouldPatchSyscall, hostarch.NoAccess, nil
+	} else if ctxState == sysmsg.ContextStateUnexpectedDeath {
+		return false, shouldPatchSyscall, hostarch.NoAccess, &platform.ContextError{
+			Err:   fmt.Errorf("systrap unexpected death"),
+			Errno: unix.ECHILD,
+		}
 	} else if ctxState != sysmsg.ContextStateFault {
 		return false, false, hostarch.NoAccess, corruptedSharedMemoryErr(fmt.Sprintf("unknown context state: %v", ctxState))
 	}
diff --git a/pkg/sentry/platform/systrap/sysmsg/sysmsg.go b/pkg/sentry/platform/systrap/sysmsg/sysmsg.go
index 60f1796ac4..9b61ab3b9a 100644
--- a/pkg/sentry/platform/systrap/sysmsg/sysmsg.go
+++ b/pkg/sentry/platform/systrap/sysmsg/sysmsg.go
@@ -172,7 +172,7 @@ type Msg struct {
 // or ContextStateNone if running/ready-to-run.
 type ContextState uint32
 
-// Set atomicaly sets the state value.
+// Set atomically sets the state value.
 func (s *ContextState) Set(state ContextState) {
 	atomic.StoreUint32((*uint32)(s), uint32(state))
 }
@@ -184,6 +184,11 @@ func (s *ContextState) Get() ContextState {
 	return ContextState(atomic.LoadUint32((*uint32)(s)))
 }
 
+// CompareAndSwap performs a compare-and-swap operation on the state value.
+func (s *ContextState) CompareAndSwap(old, new ContextState) bool {
+	return atomic.CompareAndSwapUint32((*uint32)(s), uint32(old), uint32(new))
+}
+
 // Context State types.
 const (
 	// ContextStateNone means that is either running in the user task or is ready
@@ -201,6 +206,8 @@ const (
 	// ContextStateSyscallCanBePatched means that the syscall can be replaced
 	// with a function call.
 	ContextStateSyscallCanBePatched
+	// ContextStateUnexpectedDeath means a stub thread died unexpectedly.
+	ContextStateUnexpectedDeath
 	// ContextStateInvalid is an invalid state that the sentry should never see.
 	ContextStateInvalid
 )
diff --git a/pkg/sentry/platform/systrap/sysmsg/sysmsg.h b/pkg/sentry/platform/systrap/sysmsg/sysmsg.h
index 056d2d1e0d..86b98fb117 100644
--- a/pkg/sentry/platform/systrap/sysmsg/sysmsg.h
+++ b/pkg/sentry/platform/systrap/sysmsg/sysmsg.h
@@ -75,6 +75,7 @@ enum context_state {
   CONTEXT_STATE_FAULT,
   CONTEXT_STATE_SYSCALL_TRAP,
   CONTEXT_STATE_SYSCALL_NEED_TRAP,
+  CONTEXT_STATE_UNEXPECTED_DEATH,
   CONTEXT_STATE_INVALID,
 };