From: Werner Schreiber <werner@perfect-privacy.com>
Date: Wed, 10 Oct 2018 17:16:59 +0000 (+0200)
Subject: Fix segfault when dest->mtu is 0.
X-Git-Tag: release-1.0.36~10
X-Git-Url: https://git.tinc-vpn.org/git/browse?a=commitdiff_plain;h=228a03aaa707a5fcced9dd5148a4bdb7e5ef025b;p=tinc

Fix segfault when dest->mtu is 0.
---

diff --git a/src/route.c b/src/route.c
index 850a146e..f8b11bb6 100644
--- a/src/route.c
+++ b/src/route.c
@@ -581,7 +581,7 @@ static void fragment_ipv4_packet(node_t *dest, vpn_packet_t *packet, length_t et
 	ifdebug(TRAFFIC) logger(LOG_INFO, "Fragmenting packet of %d bytes to %s (%s)", packet->len, dest->name, dest->hostname);
 
 	offset = packet->data + ether_size + ip_size;
-	maxlen = (dest->mtu - ether_size - ip_size) & ~0x7;
+	maxlen = (MAX(dest->mtu, 590) - ether_size - ip_size) & ~0x7;
 	ip_off = ntohs(ip.ip_off);
 	origf = ip_off & ~IP_OFFMASK;
 	ip_off &= IP_OFFMASK;