apply fix for underflow in WMM action frame parser

hostapd-AP-WMM-Fix-integer-underflow-in-WMM-Action-frame-par.patch

@@ -0,0 +1,41 @@
+From ef566a4d4f74022e1fdb0a2addfe81e6de9f4aae Mon Sep 17 00:00:00 2001
+From: Jouni Malinen <j@w1.fi>
+Date: Wed, 29 Apr 2015 02:21:53 +0300
+Subject: [PATCH] AP WMM: Fix integer underflow in WMM Action frame parser
+
+The length of the WMM Action frame was not properly validated and the
+length of the information elements (int left) could end up being
+negative. This would result in reading significantly past the stack
+buffer while parsing the IEs in ieee802_11_parse_elems() and while doing
+so, resulting in segmentation fault.
+
+This can result in an invalid frame being used for a denial of service
+attack (hostapd process killed) against an AP with a driver that uses
+hostapd for management frame processing (e.g., all mac80211-based
+drivers).
+
+Thanks to Kostya Kortchinsky of Google security team for discovering and
+reporting this issue.
+
+Signed-off-by: Jouni Malinen <j@w1.fi>
+---
+ src/ap/wmm.c | 3 +++
+ 1 file changed, 3 insertions(+)
+
+diff --git a/src/ap/wmm.c b/src/ap/wmm.c
+index 6d4177c..314e244 100644
+--- a/src/ap/wmm.c
++++ b/src/ap/wmm.c
+@@ -274,6 +274,9 @@ void hostapd_wmm_action(struct hostapd_data *hapd,
+ 		return;
+ 	}
+ 
++	if (left < 0)
++		return; /* not a valid WMM Action frame */
++
+ 	/* extract the tspec info element */
+ 	if (ieee802_11_parse_elems(pos, left, &elems, 1) == ParseFailed) {
+ 		hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
+-- 
+1.9.1
+

hostapd.spec

@@ -2,7 +2,7 @@
 
 Name:           hostapd
 Version:        2.4
-Release:        1%{?dist}
+Release:        2%{?dist}
 Summary:        IEEE 802.11 AP, IEEE 802.1X/WPA/WPA2/EAP/RADIUS Authenticator
 License:        BSD
 URL:            http://w1.fi/hostapd
@@ -13,6 +13,7 @@ Source2:        %{name}.conf
 Source3:        %{name}.sysconfig
 Source4:        %{name}.init
 Patch0:         %{name}-EAP-TLS-server-Fix-TLS-Message-Length-validation.patch
+Patch1:         %{name}-AP-WMM-Fix-integer-underflow-in-WMM-Action-frame-par.patch
 
 BuildRequires:  libnl3-devel
 BuildRequires:  openssl-devel
@@ -54,6 +55,8 @@ Logwatch scripts for hostapd.
 # git://w1.fi/srv/git/hostap.git
 # 	commit 586c446e0ff42ae00315b014924ec669023bd8de
 %patch0 -p1 -b .message_length
+# 	commit ef566a4d4f74022e1fdb0a2addfe81e6de9f4aae
+%patch1 -p1 -b .wmm_underflow
 
 %build
 cd hostapd
@@ -172,6 +175,9 @@ fi
 %{_sysconfdir}/logwatch/scripts/services/%{name}
 
 %changelog
+* Fri May 15 2015 John W. Linville <linville@redhat.com> - 2.4-2
+- apply fix for underflow in WMM action frame parser
+
 * Tue Apr 21 2015 John W. Linville <linville@redhat.com> - 2.4-1
 - Update to version 2.4 from upstream
 - Enable support for IEEE802.11r and IEEE802.11ac