e84d4fc50e
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 <pemensik@redhat.com>
31 lines
984 B
Diff
31 lines
984 B
Diff
From 3d4ff1ba8419546490b464418223132529514033 Mon Sep 17 00:00:00 2001
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From: Simon Kelley <simon@thekelleys.org.uk>
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Date: Mon, 25 Sep 2017 18:52:50 +0100
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Subject: [PATCH 4/9] Security fix, CVE-2017-14493, DHCPv6 - Stack buffer
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overflow.
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Fix stack overflow in DHCPv6 code. An attacker who can send
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a DHCPv6 request to dnsmasq can overflow the stack frame and
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crash or control dnsmasq.
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---
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src/rfc3315.c | 3 +++
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1 file changed, 3 insertions(+)
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diff --git a/src/rfc3315.c b/src/rfc3315.c
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index 1687931..920907c 100644
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--- a/src/rfc3315.c
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+++ b/src/rfc3315.c
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@@ -206,6 +206,9 @@ static int dhcp6_maybe_relay(struct state *state, void *inbuff, size_t sz,
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/* RFC-6939 */
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if ((opt = opt6_find(opts, end, OPTION6_CLIENT_MAC, 3)))
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{
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+ if (opt6_len(opt) - 2 > DHCP_CHADDR_MAX) {
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+ return 0;
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+ }
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state->mac_type = opt6_uint(opt, 0, 2);
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state->mac_len = opt6_len(opt) - 2;
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memcpy(&state->mac[0], opt6_ptr(opt, 2), state->mac_len);
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--
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2.9.5
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