This is a note to let you know that I've just added the patch titled mac80211/wpa: use constant time memory comparison for MACs to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mac80211-wpa-use-constant-time-memory-comparison-for-macs.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 98c67d187db7808b1f3c95f2110dd4392d034182 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" <Jason@xxxxxxxxx> Date: Sat, 10 Jun 2017 04:59:12 +0200 Subject: mac80211/wpa: use constant time memory comparison for MACs From: Jason A. Donenfeld <Jason@xxxxxxxxx> commit 98c67d187db7808b1f3c95f2110dd4392d034182 upstream. Otherwise, we enable all sorts of forgeries via timing attack. Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx> Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> Cc: linux-wireless@xxxxxxxxxxxxxxx Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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; } Patches currently in stable-queue which might be from Jason@xxxxxxxxx are queue-4.4/mac80211-wpa-use-constant-time-memory-comparison-for-macs.patch