From: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Tue, 17 Oct 2017 18:32:07 +0000 (+0200)
Subject: mac80211: use constant time comparison with keys
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=2bdd713b92a9cade239d3c7d15205a09f556624d;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

mac80211: use constant time comparison with keys

Otherwise we risk leaking information via timing side channel.

Fixes: fdf7cb4185b6 ("mac80211: accept key reinstall without changing anything")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---

diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index ae995c8480db..035d16fe926e 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -19,6 +19,7 @@
 #include <linux/slab.h>
 #include <linux/export.h>
 #include <net/mac80211.h>
+#include <crypto/algapi.h>
 #include <asm/unaligned.h>
 #include "ieee80211_i.h"
 #include "driver-ops.h"
@@ -635,7 +636,7 @@ int ieee80211_key_link(struct ieee80211_key *key,
 	 * 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)) {
+	    !crypto_memneq(key->conf.key, old_key->conf.key, key->conf.keylen)) {
 		ieee80211_key_free_unused(key);
 		ret = 0;
 		goto out;