mac80211: use constant time comparison with keys

Otherwise we risk leaking information via timing side channel. Change-Id: I777afd16f7b0ca8a5ab1b95ddc66689afdc96636 Fixes: fdf7cb4185b6 ("mac80211: accept key reinstall without changing anything") Signed-off-by: Jason A. Donenfeld <[email protected]> Signed-off-by: Johannes Berg <[email protected]>
ppajda · Oct 23, 2017 · d6927ac · d6927ac
1 parent ab03f36
commit d6927ac
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/net/mac80211/key.c b/net/mac80211/key.c
@@ -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;