From d2d1a324ce937628e4d9d9999fe113819b7d4478 Mon Sep 17 00:00:00 2001
From: Jouni Malinen <jouni@codeaurora.org>
Date: Wed, 17 Apr 2019 02:21:20 +0300
Subject: [PATCH 3/3] EAP-pwd peer: Fix reassembly buffer handling

Unexpected fragment might result in data->inbuf not being allocated
before processing and that could have resulted in NULL pointer
dereference. Fix that by explicitly checking for data->inbuf to be
available before using it.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Upstream-Status: Backport
CVE: CVE-2019-11555
---
 src/eap_peer/eap_pwd.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/eap_peer/eap_pwd.c b/src/eap_peer/eap_pwd.c
index 46894a5..76fcad4 100644
--- a/src/eap_peer/eap_pwd.c
+++ b/src/eap_peer/eap_pwd.c
@@ -932,6 +932,13 @@ eap_pwd_process(struct eap_sm *sm, void *priv, struct eap_method_ret *ret,
 	 * buffer and ACK the fragment
 	 */
 	if (EAP_PWD_GET_MORE_BIT(lm_exch) || data->in_frag_pos) {
+		if (!data->inbuf) {
+			wpa_printf(MSG_DEBUG,
+				   "EAP-pwd: No buffer for reassembly");
+			ret->methodState = METHOD_DONE;
+			ret->decision = DECISION_FAIL;
+			return NULL;
+		}
 		data->in_frag_pos += len;
 		if (data->in_frag_pos > wpabuf_size(data->inbuf)) {
 			wpa_printf(MSG_INFO, "EAP-pwd: Buffer overflow attack "
@@ -958,7 +965,7 @@ eap_pwd_process(struct eap_sm *sm, void *priv, struct eap_method_ret *ret,
 	/*
 	 * we're buffering and this is the last fragment
 	 */
-	if (data->in_frag_pos) {
+	if (data->in_frag_pos && data->inbuf) {
 		wpa_printf(MSG_DEBUG, "EAP-pwd: Last fragment, %d bytes",
 			   (int) len);
 		pos = wpabuf_head_u8(data->inbuf);
-- 
2.7.4

