From ac222521abd476acc21c3dd777853c883b91503d Mon Sep 17 00:00:00 2001
From: "Martine S. Lenders" <mail@martine-lenders.eu>
Date: Wed, 25 Mar 2020 14:54:18 +0100
Subject: [PATCH] gnrc_sixlowpan_iphc: zero IPv6 header before decompressing
 into it

---
 .../gnrc/network_layer/sixlowpan/iphc/gnrc_sixlowpan_iphc.c    | 3 +++
 1 file changed, 3 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 33521af52b..54cede6288 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
@@ -158,6 +158,9 @@ static size_t _iphc_ipv6_decode(const uint8_t *iphc_hdr,
         payload_offset++;
     }
 
+    /* bits of the uncompressed address might not be written in decompression,
+     * so zero the whole header first */
+    memset(ipv6_hdr, 0, sizeof(*ipv6_hdr));
     ipv6_hdr_set_version(ipv6_hdr);
 
     switch (iphc_hdr[IPHC1_IDX] & SIXLOWPAN_IPHC1_TF) {