diff --git a/sys/netipsec/xform_esp.c b/sys/netipsec/xform_esp.c
--- a/sys/netipsec/xform_esp.c
+++ b/sys/netipsec/xform_esp.c
@@ -508,6 +508,11 @@
 	xd = crp->crp_opaque;
 	CURVNET_SET(xd->vnet);
 	sav = xd->sav;
+	if (sav->state >= SADB_SASTATE_DEAD) {
+		/* saidx is freed */
+		error = ESRCH;
+		goto bad;
+	}
 	skip = xd->skip;
 	protoff = xd->protoff;
 	cryptoid = xd->cryptoid;