From 709ddd2ba75dcc3cb0ed0e107f39a1bd9757c2a1 Mon Sep 17 00:00:00 2001
From: Martine Lenders <m.lenders@fu-berlin.de>
Date: Fri, 23 Dec 2022 13:06:11 +0100
Subject: [PATCH] gnrc_sixlowpan_iphc: check IPHC dispatch for truncation

---
 .../network_layer/sixlowpan/iphc/gnrc_sixlowpan_iphc.c    | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/sys/net/gnrc/network_layer/sixlowpan/iphc/gnrc_sixlowpan_iphc.c b/sys/net/gnrc/network_layer/sixlowpan/iphc/gnrc_sixlowpan_iphc.c
index 430a694ed8..29118c5cf2 100644
--- a/sys/net/gnrc/network_layer/sixlowpan/iphc/gnrc_sixlowpan_iphc.c
+++ b/sys/net/gnrc/network_layer/sixlowpan/iphc/gnrc_sixlowpan_iphc.c
@@ -734,6 +734,14 @@ void gnrc_sixlowpan_iphc_recv(gnrc_pktsnip_t *sixlo, void *rbuf_ptr,
     gnrc_sixlowpan_frag_vrb_t *vrbe = NULL;
 #endif  /* MODULE_GNRC_SIXLOWPAN_FRAG_VRB */
 
+    if (sixlo->size < 2U) {
+        DEBUG("6lo iphc: IPHC header truncated\n");
+        if (rbuf != NULL) {
+            gnrc_sixlowpan_frag_rb_remove(rbuf);
+        }
+        gnrc_pktbuf_release(sixlo);
+        return;
+    }
     if (rbuf != NULL) {
         ipv6 = rbuf->pkt;
         assert(ipv6 != NULL);