mac80211: fix CMAC races

Just like TKIP and CCMP, CMAC has the PN race.
It might not actually be possible to hit it now
since there aren't multiple ACs for management
frames, but fix it anyway.

Also move scratch buffers onto the stack.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/net/mac80211/aes_cmac.c b/net/mac80211/aes_cmac.c
index d502b2684a66..08b0f1768aad 100644
--- a/net/mac80211/aes_cmac.c
+++ b/net/mac80211/aes_cmac.c
@@ -35,10 +35,10 @@ static void gf_mulx(u8 *pad)
 }
 
 
-static void aes_128_cmac_vector(struct crypto_cipher *tfm, u8 *scratch,
-                                size_t num_elem,
+static void aes_128_cmac_vector(struct crypto_cipher *tfm, size_t num_elem,
                                 const u8 *addr[], const size_t *len, u8 *mac)
 {
+        u8 scratch[2 * AES_BLOCK_SIZE];
         u8 *cbc, *pad;
         const u8 *pos, *end;
         size_t i, e, left, total_len;
@@ -95,7 +95,7 @@ static void aes_128_cmac_vector(struct crypto_cipher *tfm, u8 *scratch,
 }
 
 
-void ieee80211_aes_cmac(struct crypto_cipher *tfm, u8 *scratch, const u8 *aad,
+void ieee80211_aes_cmac(struct crypto_cipher *tfm, const u8 *aad,
                         const u8 *data, size_t data_len, u8 *mic)
 {
         const u8 *addr[3];
@@ -110,7 +110,7 @@ void ieee80211_aes_cmac(struct crypto_cipher *tfm, u8 *scratch, const u8 *aad,
         addr[2] = zero;
         len[2] = CMAC_TLEN;
 
-        aes_128_cmac_vector(tfm, scratch, 3, addr, len, mic);
+        aes_128_cmac_vector(tfm, 3, addr, len, mic);
 }