1 files changed, 17 insertions, 1 deletions
diff --git a/pkg/rpcserver/runner.go b/pkg/rpcserver/runner.go
index 45b376a79..1af35b6d2 100644
--- a/pkg/rpcserver/runner.go
+++ b/pkg/rpcserver/runner.go
@@ -42,6 +42,7 @@ type Runner struct {
 	nextRequestID int64
 	requests      map[int64]*queue.Request
 	executing     map[int64]bool
+	hanged        map[int64]bool
 	lastExec      *LastExecuting
 	updInfo       dispatcher.UpdateInfo
 	resultCh      chan error
@@ -343,10 +344,13 @@ func (runner *Runner) sendRequest(req *queue.Request) error {
 func (runner *Runner) handleExecutingMessage(msg *flatrpc.ExecutingMessage) error {
 	req := runner.requests[msg.Id]
 	if req == nil {
+		if runner.hanged[msg.Id] {
+			return nil
+		}
 		return fmt.Errorf("can't find executing request %v", msg.Id)
 	}
 	proc := int(msg.ProcId)
-	if proc < 0 || proc >= runner.procs {
+	if proc < 0 || proc >= prog.MaxPids {
 		return fmt.Errorf("got bad proc id %v", proc)
 	}
 	runner.stats.statExecs.Add(1)
@@ -372,6 +376,14 @@ func (runner *Runner) handleExecutingMessage(msg *flatrpc.ExecutingMessage) erro
 func (runner *Runner) handleExecResult(msg *flatrpc.ExecResult) error {
 	req := runner.requests[msg.Id]
 	if req == nil {
+		if runner.hanged[msg.Id] {
+			// Got result for a program that was previously reported hanged
+			// (probably execution was just extremely slow). Can't report result
+			// to pkg/fuzzer since it already handled completion of the request,
+			// but shouldn't report an error and crash the VM as well.
+			delete(runner.hanged, msg.Id)
+			return nil
+		}
 		return fmt.Errorf("can't find executed request %v", msg.Id)
 	}
 	delete(runner.requests, msg.Id)
@@ -410,6 +422,10 @@ func (runner *Runner) handleExecResult(msg *flatrpc.ExecResult) error {
 	if msg.Error != "" {
 		status = queue.ExecFailure
 		resErr = errors.New(msg.Error)
+	} else if msg.Hanged {
+		status = queue.Hanged
+		runner.lastExec.Hanged(int(msg.Id), int(msg.Proc), req.Prog.Serialize(), osutil.MonotonicNano())
+		runner.hanged[msg.Id] = true
 	}
 	req.Done(&queue.Result{
 		Executor: queue.ExecutorID{