From 17fdf61cbe3dc4f99586d9e08eef36f0a1bfc575 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Wed, 6 Oct 2021 23:25:59 +0200
Subject: [PATCH] ieee802154/submac: handle write of NULL buffer

tests/socket_zep tests for this condition, so we better handle it
gracefully instead of crashing.
---
 sys/net/link_layer/ieee802154/submac.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sys/net/link_layer/ieee802154/submac.c b/sys/net/link_layer/ieee802154/submac.c
index 3025ef103a..fc483c0064 100644
--- a/sys/net/link_layer/ieee802154/submac.c
+++ b/sys/net/link_layer/ieee802154/submac.c
@@ -406,6 +406,10 @@ int ieee802154_send(ieee802154_submac_t *submac, const iolist_t *iolist)
         return -EBUSY;
     }
 
+    if (iolist == NULL) {
+        return 0;
+    }
+
     uint8_t *buf = iolist->iol_base;
     bool cnf = buf[0] & IEEE802154_FCF_ACK_REQ;