diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 0df1b0f..eac6875 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -951,6 +951,11 @@
 		return;
 	}
 
+	if (WARN_ON_ONCE(pid < 0)) {
+		strcpy(comm, "<XXX>");
+		return;
+	}
+
 	if (pid > PID_MAX_DEFAULT) {
 		strcpy(comm, "<...>");
 		return;