hostapd: merge an upstream patch for pmksa cache

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

Backport of r42762

git-svn-id: svn://svn.openwrt.org/openwrt/branches/barrier_breaker@42763 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/network/services/hostapd/patches/001-fix_pmksa_cache.patch

+From 9c829900bb01d6fb22e78ba78195c78de39f64b9 Mon Sep 17 00:00:00 2001
+From: Jouni Malinen <j@w1.fi>
+Date: Sat, 04 Oct 2014 19:11:00 +0000
+Subject: Fix authenticator OKC fetch from PMKSA cache to avoid infinite loop
+
+If the first entry in the PMKSA cache did not match the station's MAC
+address, an infinite loop could be reached in pmksa_cache_get_okc() when
+trying to find a PMKSA cache entry for opportunistic key caching cases.
+This would only happen if OKC is enabled (okc=1 included in the
+configuration file).
+
+Signed-off-by: Jouni Malinen <j@w1.fi>
+---
+--- a/src/ap/pmksa_cache_auth.c
++++ b/src/ap/pmksa_cache_auth.c
+@@ -394,15 +394,13 @@ struct rsn_pmksa_cache_entry * pmksa_cac
+ 	struct rsn_pmksa_cache_entry *entry;
+ 	u8 new_pmkid[PMKID_LEN];
+ 
+-	entry = pmksa->pmksa;
+-	while (entry) {
++	for (entry = pmksa->pmksa; entry; entry = entry->next) {
+ 		if (os_memcmp(entry->spa, spa, ETH_ALEN) != 0)
+ 			continue;
+ 		rsn_pmkid(entry->pmk, entry->pmk_len, aa, spa, new_pmkid,
+ 			  wpa_key_mgmt_sha256(entry->akmp));
+ 		if (os_memcmp(new_pmkid, pmkid, PMKID_LEN) == 0)
+ 			return entry;
+-		entry = entry->next;
+ 	}
+ 	return NULL;
+ }