diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -381,7 +381,7 @@
 int
 sys_sigaction(struct sysmsg *sysmsg, const struct sigaction_args *uap)
 {
-	struct sigaction act, oact;
+	struct sigaction act = { 0 }, oact = { 0 };
 	struct sigaction *actp, *oactp;
 	int error;