From 2f701194c29da50bfda968a83c6609843f74a7f4 Mon Sep 17 00:00:00 2001 From: Stijn Tintel Date: Tue, 17 Oct 2017 01:49:58 +0300 Subject: [PATCH] mac80211: backport kernel fix for CVE-2017-13080 Signed-off-by: Stijn Tintel --- ...key-reinstall-without-changing-anyth.patch | 81 +++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 package/kernel/mac80211/patches/327-mac80211-accept-key-reinstall-without-changing-anyth.patch diff --git a/package/kernel/mac80211/patches/327-mac80211-accept-key-reinstall-without-changing-anyth.patch b/package/kernel/mac80211/patches/327-mac80211-accept-key-reinstall-without-changing-anyth.patch new file mode 100644 index 00000000000..7d0be0395be --- /dev/null +++ b/package/kernel/mac80211/patches/327-mac80211-accept-key-reinstall-without-changing-anyth.patch @@ -0,0 +1,81 @@ +From fdf7cb4185b60c68e1a75e61691c4afdc15dea0e Mon Sep 17 00:00:00 2001 +From: Johannes Berg +Date: Tue, 5 Sep 2017 14:54:54 +0200 +Subject: [PATCH] mac80211: accept key reinstall without changing anything + +When a key is reinstalled we can reset the replay counters +etc. which can lead to nonce reuse and/or replay detection +being impossible, breaking security properties, as described +in the "KRACK attacks". + +In particular, CVE-2017-13080 applies to GTK rekeying that +happened in firmware while the host is in D3, with the second +part of the attack being done after the host wakes up. In +this case, the wpa_supplicant mitigation isn't sufficient +since wpa_supplicant doesn't know the GTK material. + +In case this happens, simply silently accept the new key +coming from userspace but don't take any action on it since +it's the same key; this keeps the PN replay counters intact. + +Signed-off-by: Johannes Berg +--- + net/mac80211/key.c | 21 +++++++++++++++++---- + 1 file changed, 17 insertions(+), 4 deletions(-) + +diff --git a/net/mac80211/key.c b/net/mac80211/key.c +index a98fc2b5e0dc..ae995c8480db 100644 +--- a/net/mac80211/key.c ++++ b/net/mac80211/key.c +@@ -4,7 +4,7 @@ + * Copyright 2006-2007 Jiri Benc + * Copyright 2007-2008 Johannes Berg + * Copyright 2013-2014 Intel Mobile Communications GmbH +- * Copyright 2015 Intel Deutschland GmbH ++ * Copyright 2015-2017 Intel Deutschland GmbH + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as +@@ -620,9 +620,6 @@ int ieee80211_key_link(struct ieee80211_key *key, + + pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE; + idx = key->conf.keyidx; +- key->local = sdata->local; +- key->sdata = sdata; +- key->sta = sta; + + mutex_lock(&sdata->local->key_mtx); + +@@ -633,6 +630,21 @@ int ieee80211_key_link(struct ieee80211_key *key, + else + old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]); + ++ /* ++ * Silently accept key re-installation without really installing the ++ * new version of the key to avoid nonce reuse or replay issues. ++ */ ++ if (old_key && key->conf.keylen == old_key->conf.keylen && ++ !memcmp(key->conf.key, old_key->conf.key, key->conf.keylen)) { ++ ieee80211_key_free_unused(key); ++ ret = 0; ++ goto out; ++ } ++ ++ key->local = sdata->local; ++ key->sdata = sdata; ++ key->sta = sta; ++ + increment_tailroom_need_count(sdata); + + ieee80211_key_replace(sdata, sta, pairwise, old_key, key); +@@ -648,6 +660,7 @@ int ieee80211_key_link(struct ieee80211_key *key, + ret = 0; + } + ++ out: + mutex_unlock(&sdata->local->key_mtx); + + return ret; +-- +2.13.6 + -- 2.30.2