1 From 5086b12a4b1269d1576b5bab01f72c6fa19c55bc Mon Sep 17 00:00:00 2001
2 From: Simon Kelley <simon@thekelleys.org.uk>
3 Date: Mon, 25 Sep 2017 18:52:50 +0100
4 Subject: [PATCH 3/9] Security fix, CVE-2017-14493, DHCPv6 - Stack buffer
7 Fix stack overflow in DHCPv6 code. An attacker who can send
8 a DHCPv6 request to dnsmasq can overflow the stack frame and
9 crash or control dnsmasq.
12 1 file changed, 3 insertions(+)
14 diff --git a/src/rfc3315.c b/src/rfc3315.c
15 index 73bdee4..8d18a28 100644
18 @@ -206,6 +206,9 @@ static int dhcp6_maybe_relay(struct state *state, void *inbuff, size_t sz,
20 if ((opt = opt6_find(opts, end, OPTION6_CLIENT_MAC, 3)))
22 + if (opt6_len(opt) - 2 > DHCP_CHADDR_MAX) {
25 state->mac_type = opt6_uint(opt, 0, 2);
26 state->mac_len = opt6_len(opt) - 2;
27 memcpy(&state->mac[0], opt6_ptr(opt, 2), state->mac_len);