lib80211: Remove VLA usage of skcipher

In the quest to remove all stack VLA usage from the kernel[1], this
replaces struct crypto_skcipher and SKCIPHER_REQUEST_ON_STACK() usage
with struct crypto_sync_skcipher and SYNC_SKCIPHER_REQUEST_ON_STACK(),
which uses a fixed stack size.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: linux-wireless@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Kees Cook
2018-09-18 19:10:40 -07:00
committed by Herbert Xu
parent e9e575b8f2
commit db20f570e1
6 changed files with 89 additions and 95 deletions

View File

@@ -64,9 +64,9 @@ struct lib80211_tkip_data {
int key_idx;
struct crypto_skcipher *rx_tfm_arc4;
struct crypto_sync_skcipher *rx_tfm_arc4;
struct crypto_shash *rx_tfm_michael;
struct crypto_skcipher *tx_tfm_arc4;
struct crypto_sync_skcipher *tx_tfm_arc4;
struct crypto_shash *tx_tfm_michael;
/* scratch buffers for virt_to_page() (crypto API) */
@@ -99,8 +99,7 @@ static void *lib80211_tkip_init(int key_idx)
priv->key_idx = key_idx;
priv->tx_tfm_arc4 = crypto_alloc_skcipher("ecb(arc4)", 0,
CRYPTO_ALG_ASYNC);
priv->tx_tfm_arc4 = crypto_alloc_sync_skcipher("ecb(arc4)", 0, 0);
if (IS_ERR(priv->tx_tfm_arc4)) {
priv->tx_tfm_arc4 = NULL;
goto fail;
@@ -112,8 +111,7 @@ static void *lib80211_tkip_init(int key_idx)
goto fail;
}
priv->rx_tfm_arc4 = crypto_alloc_skcipher("ecb(arc4)", 0,
CRYPTO_ALG_ASYNC);
priv->rx_tfm_arc4 = crypto_alloc_sync_skcipher("ecb(arc4)", 0, 0);
if (IS_ERR(priv->rx_tfm_arc4)) {
priv->rx_tfm_arc4 = NULL;
goto fail;
@@ -130,9 +128,9 @@ static void *lib80211_tkip_init(int key_idx)
fail:
if (priv) {
crypto_free_shash(priv->tx_tfm_michael);
crypto_free_skcipher(priv->tx_tfm_arc4);
crypto_free_sync_skcipher(priv->tx_tfm_arc4);
crypto_free_shash(priv->rx_tfm_michael);
crypto_free_skcipher(priv->rx_tfm_arc4);
crypto_free_sync_skcipher(priv->rx_tfm_arc4);
kfree(priv);
}
@@ -144,9 +142,9 @@ static void lib80211_tkip_deinit(void *priv)
struct lib80211_tkip_data *_priv = priv;
if (_priv) {
crypto_free_shash(_priv->tx_tfm_michael);
crypto_free_skcipher(_priv->tx_tfm_arc4);
crypto_free_sync_skcipher(_priv->tx_tfm_arc4);
crypto_free_shash(_priv->rx_tfm_michael);
crypto_free_skcipher(_priv->rx_tfm_arc4);
crypto_free_sync_skcipher(_priv->rx_tfm_arc4);
}
kfree(priv);
}
@@ -344,7 +342,7 @@ static int lib80211_tkip_hdr(struct sk_buff *skb, int hdr_len,
static int lib80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
struct lib80211_tkip_data *tkey = priv;
SKCIPHER_REQUEST_ON_STACK(req, tkey->tx_tfm_arc4);
SYNC_SKCIPHER_REQUEST_ON_STACK(req, tkey->tx_tfm_arc4);
int len;
u8 rc4key[16], *pos, *icv;
u32 crc;
@@ -374,9 +372,9 @@ static int lib80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
icv[2] = crc >> 16;
icv[3] = crc >> 24;
crypto_skcipher_setkey(tkey->tx_tfm_arc4, rc4key, 16);
crypto_sync_skcipher_setkey(tkey->tx_tfm_arc4, rc4key, 16);
sg_init_one(&sg, pos, len + 4);
skcipher_request_set_tfm(req, tkey->tx_tfm_arc4);
skcipher_request_set_sync_tfm(req, tkey->tx_tfm_arc4);
skcipher_request_set_callback(req, 0, NULL, NULL);
skcipher_request_set_crypt(req, &sg, &sg, len + 4, NULL);
err = crypto_skcipher_encrypt(req);
@@ -400,7 +398,7 @@ static inline int tkip_replay_check(u32 iv32_n, u16 iv16_n,
static int lib80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
{
struct lib80211_tkip_data *tkey = priv;
SKCIPHER_REQUEST_ON_STACK(req, tkey->rx_tfm_arc4);
SYNC_SKCIPHER_REQUEST_ON_STACK(req, tkey->rx_tfm_arc4);
u8 rc4key[16];
u8 keyidx, *pos;
u32 iv32;
@@ -463,9 +461,9 @@ static int lib80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
plen = skb->len - hdr_len - 12;
crypto_skcipher_setkey(tkey->rx_tfm_arc4, rc4key, 16);
crypto_sync_skcipher_setkey(tkey->rx_tfm_arc4, rc4key, 16);
sg_init_one(&sg, pos, plen + 4);
skcipher_request_set_tfm(req, tkey->rx_tfm_arc4);
skcipher_request_set_sync_tfm(req, tkey->rx_tfm_arc4);
skcipher_request_set_callback(req, 0, NULL, NULL);
skcipher_request_set_crypt(req, &sg, &sg, plen + 4, NULL);
err = crypto_skcipher_decrypt(req);
@@ -660,9 +658,9 @@ static int lib80211_tkip_set_key(void *key, int len, u8 * seq, void *priv)
struct lib80211_tkip_data *tkey = priv;
int keyidx;
struct crypto_shash *tfm = tkey->tx_tfm_michael;
struct crypto_skcipher *tfm2 = tkey->tx_tfm_arc4;
struct crypto_sync_skcipher *tfm2 = tkey->tx_tfm_arc4;
struct crypto_shash *tfm3 = tkey->rx_tfm_michael;
struct crypto_skcipher *tfm4 = tkey->rx_tfm_arc4;
struct crypto_sync_skcipher *tfm4 = tkey->rx_tfm_arc4;
keyidx = tkey->key_idx;
memset(tkey, 0, sizeof(*tkey));