* [PATCH 4.4 06/30] mac80211/wpa: use constant time memory comparison for MACs
[not found] <20170619152033.211450261@linuxfoundation.org>
@ 2017-06-19 15:20 ` Greg Kroah-Hartman
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From: Greg Kroah-Hartman @ 2017-06-19 15:20 UTC (permalink / raw)
To: linux-kernel
Cc: Greg Kroah-Hartman, stable, Jason A. Donenfeld, Johannes Berg,
linux-wireless, Johannes Berg
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jason A. Donenfeld <Jason@zx2c4.com>
commit 98c67d187db7808b1f3c95f2110dd4392d034182 upstream.
Otherwise, we enable all sorts of forgeries via timing attack.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: linux-wireless@vger.kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/mac80211/wpa.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -16,6 +16,7 @@
#include <asm/unaligned.h>
#include <net/mac80211.h>
#include <crypto/aes.h>
+#include <crypto/algapi.h>
#include "ieee80211_i.h"
#include "michael.h"
@@ -152,7 +153,7 @@ ieee80211_rx_h_michael_mic_verify(struct
data_len = skb->len - hdrlen - MICHAEL_MIC_LEN;
key = &rx->key->conf.key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY];
michael_mic(key, hdr, data, data_len, mic);
- if (memcmp(mic, data + data_len, MICHAEL_MIC_LEN) != 0)
+ if (crypto_memneq(mic, data + data_len, MICHAEL_MIC_LEN))
goto mic_fail;
/* remove Michael MIC from payload */
@@ -1044,7 +1045,7 @@ ieee80211_crypto_aes_cmac_decrypt(struct
bip_aad(skb, aad);
ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
skb->data + 24, skb->len - 24, mic);
- if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
+ if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
key->u.aes_cmac.icverrors++;
return RX_DROP_UNUSABLE;
}
@@ -1094,7 +1095,7 @@ ieee80211_crypto_aes_cmac_256_decrypt(st
bip_aad(skb, aad);
ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
skb->data + 24, skb->len - 24, mic);
- if (memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
+ if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
key->u.aes_cmac.icverrors++;
return RX_DROP_UNUSABLE;
}
@@ -1198,7 +1199,7 @@ ieee80211_crypto_aes_gmac_decrypt(struct
if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
skb->data + 24, skb->len - 24,
mic) < 0 ||
- memcmp(mic, mmie->mic, sizeof(mmie->mic)) != 0) {
+ crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
key->u.aes_gmac.icverrors++;
return RX_DROP_UNUSABLE;
}
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