diff mbox

mac80211: use constant time comparison with keys

Message ID 20171017183207.23124-1-Jason@zx2c4.com (mailing list archive)
State Accepted
Delegated to: Johannes Berg
Headers show

Commit Message

Jason A. Donenfeld Oct. 17, 2017, 6:32 p.m. UTC 
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>
---
 net/mac80211/key.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Johannes Berg Oct. 18, 2017, 10:17 a.m. UTC | #1 
On Tue, 2017-10-17 at 20:32 +0200, Jason A. Donenfeld wrote:
> Otherwise we risk leaking information via timing side channel.
> 
Applied.

johannes
diff mbox

Patch

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;