mac80211: Allocate a sync skcipher explicitly for FILS AEAD

The skcipher could have been of the async variant which may return from
skcipher_encrypt() with -EINPROGRESS after having queued the request.
The FILS AEAD implementation here does not have code for dealing with
that possibility, so allocate a sync cipher explicitly to avoid
potential issues with hardware accelerators.

This is based on the patch sent out by Ard.

Fixes: 39404feee6 ("mac80211: FILS AEAD protection for station mode association frames")
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/fils_aead.c

@@ -124,7 +124,7 @@ static int aes_siv_encrypt(const u8 *key, size_t key_len,
 
 	/* CTR */
 
-	tfm2 = crypto_alloc_skcipher("ctr(aes)", 0, 0);
+	tfm2 = crypto_alloc_skcipher("ctr(aes)", 0, CRYPTO_ALG_ASYNC);
 	if (IS_ERR(tfm2)) {
 		kfree(tmp);
 		return PTR_ERR(tfm2);
@@ -183,7 +183,7 @@ static int aes_siv_decrypt(const u8 *key, size_t key_len,
 
 	/* CTR */
 
-	tfm2 = crypto_alloc_skcipher("ctr(aes)", 0, 0);
+	tfm2 = crypto_alloc_skcipher("ctr(aes)", 0, CRYPTO_ALG_ASYNC);
 	if (IS_ERR(tfm2))
 		return PTR_ERR(tfm2);
 	/* K2 for CTR */