mac80211: use constant time comparison with keys

Otherwise we risk leaking information via timing side channel.

Change-Id: I9d6f1a4606312d3854746aa2eec2ec46d5629a2b
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>
This commit is contained in:
Jason A. Donenfeld 2017-10-17 20:32:07 +02:00 committed by followmsi
parent 9df43dc655
commit 321cf8d2d4

View file

@ -18,6 +18,7 @@
#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"
@ -494,7 +495,7 @@ 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;