pemensik pushed to dnsmasq (f26). "Security fix, CVE-2017-14493, DHCPv6 - Stack buffer overflow. (..more)"

From 1bca83a5d36c969c4e8c2c2343d592e57094903d Mon Sep 17 00:00:00 2001
From: Petr Menšík 
Date: Oct 02 2017 15:37:39 +0000
Subject: Security fix, CVE-2017-14493, DHCPv6 - Stack buffer overflow.

Fix stack overflow in DHCPv6 code. An attacker who can send
a DHCPv6 request to dnsmasq can overflow the stack frame and
crash or control dnsmasq.

Signed-off-by: Petr Menšík

---

diff --git a/dnsmasq-2.77-CVE-2017-14493.patch b/dnsmasq-2.77-CVE-2017-14493.patch
new file mode 100644
index 0000000..d80553c
--- /dev/null
+++ b/dnsmasq-2.77-CVE-2017-14493.patch
@@ -0,0 +1,30 @@
+From 3d4ff1ba8419546490b464418223132529514033 Mon Sep 17 00:00:00 2001
+From: Simon Kelley 
+Date: Mon, 25 Sep 2017 18:52:50 +0100
+Subject: [PATCH 4/9] Security fix, CVE-2017-14493, DHCPv6 - Stack buffer
+ overflow.
+
+Fix stack overflow in DHCPv6 code. An attacker who can send
+a DHCPv6 request to dnsmasq can overflow the stack frame and
+crash or control dnsmasq.
+---
+ src/rfc3315.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/src/rfc3315.c b/src/rfc3315.c
+index 1687931..920907c 100644
+--- a/src/rfc3315.c
++++ b/src/rfc3315.c
+@@ -206,6 +206,9 @@ static int dhcp6_maybe_relay(struct state *state, void *inbuff, size_t sz,
+   /* RFC-6939 */
+   if ((opt = opt6_find(opts, end, OPTION6_CLIENT_MAC, 3)))
+     {
++      if (opt6_len(opt) - 2 > DHCP_CHADDR_MAX) {
++        return 0;
++      }
+       state->mac_type = opt6_uint(opt, 0, 2);
+       state->mac_len = opt6_len(opt) - 2;
+       memcpy(&state->mac[0], opt6_ptr(opt, 2), state->mac_len);
+-- 
+2.9.5
+
diff --git a/dnsmasq.spec b/dnsmasq.spec
index c6b7699..0e7246e 100644
--- a/dnsmasq.spec
+++ b/dnsmasq.spec
@@ -27,6 +27,7 @@ Source1:        %{name}.service
 Patch0:         dnsmasq-2.76-dns-sleep-resume.patch
 Patch2:         dnsmasq-2.77-CVE-2017-14491.patch
 Patch3:         dnsmasq-2.77-CVE-2017-14492.patch
+Patch4:         dnsmasq-2.77-CVE-2017-14493.patch

BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)

@@ -64,6 +65,7 @@ query/remove a DHCP server's leases.
 %patch0 -p1
 %patch2 -p1 -b .CVE-2017-14491
 %patch3 -p1 -b .CVE-2017-14492
+%patch4 -p1 -b .CVE-2017-14493

# use /var/lib/dnsmasq instead of /var/lib/misc
 for file in dnsmasq.conf.example man/dnsmasq.8 man/es/dnsmasq.8 src/config.h; do
@@ -152,8 +154,9 @@ rm -rf $RPM_BUILD_ROOT

%changelog
 * Mon Oct 02 2017 Petr Menšík  - 2.76-4
-- Security fix, CVE-2017-14491 DNS heap buffer overflow
-- Security fix, CVE-2017-14492 DHCPv6 RA heap overflow
+- Security fix, CVE-2017-14491, DNS heap buffer overflow
+- Security fix, CVE-2017-14492, DHCPv6 RA heap overflow
+- Security fix, CVE-2017-14493, DHCPv6 - Stack buffer overflow

* Fri Feb 10 2017 Fedora Release Engineering  - 2.76-3
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_26_Mass_Rebuild

https://src.fedoraproject.org/rpms/dnsmasq/c/1bca83a5d36c969c4e8c2c2343d592e...