52 lines
1.9 KiB
Diff
52 lines
1.9 KiB
Diff
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From bef802ece03f9ae9d52a21f0cf4f1bc2c5a1f8aa Mon Sep 17 00:00:00 2001
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From: Jouni Malinen <j@w1.fi>
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Date: Sun, 1 Nov 2015 18:24:16 +0200
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Subject: [PATCH] EAP-pwd server: Fix last fragment length validation
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All but the last fragment had their length checked against the remaining
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room in the reassembly buffer. This allowed a suitably constructed last
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fragment frame to try to add extra data that would go beyond the buffer.
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The length validation code in wpabuf_put_data() prevents an actual
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buffer write overflow from occurring, but this results in process
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termination. (CVE-2015-5314)
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Signed-off-by: Jouni Malinen <j@w1.fi>
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---
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src/eap_server/eap_server_pwd.c | 6 +++---
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1 file changed, 3 insertions(+), 3 deletions(-)
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diff --git a/src/eap_server/eap_server_pwd.c b/src/eap_server/eap_server_pwd.c
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index cb83ff7..9f787ab 100644
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--- a/src/eap_server/eap_server_pwd.c
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+++ b/src/eap_server/eap_server_pwd.c
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@@ -970,7 +970,7 @@ static void eap_pwd_process(struct eap_sm *sm, void *priv,
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/*
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* the first and all intermediate fragments have the M bit set
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*/
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- if (EAP_PWD_GET_MORE_BIT(lm_exch)) {
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+ if (EAP_PWD_GET_MORE_BIT(lm_exch) || data->in_frag_pos) {
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if ((data->in_frag_pos + len) > wpabuf_size(data->inbuf)) {
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wpa_printf(MSG_DEBUG, "EAP-pwd: Buffer overflow "
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"attack detected! (%d+%d > %d)",
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@@ -981,6 +981,8 @@ static void eap_pwd_process(struct eap_sm *sm, void *priv,
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}
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wpabuf_put_data(data->inbuf, pos, len);
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data->in_frag_pos += len;
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+ }
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+ if (EAP_PWD_GET_MORE_BIT(lm_exch)) {
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wpa_printf(MSG_DEBUG, "EAP-pwd: Got a %d byte fragment",
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(int) len);
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return;
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@@ -990,8 +992,6 @@ static void eap_pwd_process(struct eap_sm *sm, void *priv,
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* buffering fragments so that's how we know it's the last)
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*/
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if (data->in_frag_pos) {
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- wpabuf_put_data(data->inbuf, pos, len);
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- data->in_frag_pos += len;
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pos = wpabuf_head_u8(data->inbuf);
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len = data->in_frag_pos;
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wpa_printf(MSG_DEBUG, "EAP-pwd: Last fragment, %d bytes",
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--
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1.9.1
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