Commit 79140335 authored by David S. Miller's avatar David S. Miller

Merge branch 'tls-don-t-leave-keys-in-kernel-memory'

Sabrina Dubroca says:

====================
tls: don't leave keys in kernel memory

There are a few places where the RX/TX key for a TLS socket is copied
to kernel memory. This series clears those memory areas when they're no
longer needed.

v2: add union tls_crypto_context, following Vakul Garg's comment
    swap patch 2 and 3, using new union in patch 3
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents f0e0d044 c844eb46
......@@ -171,15 +171,14 @@ struct cipher_context {
char *rec_seq;
};
union tls_crypto_context {
struct tls_crypto_info info;
struct tls12_crypto_info_aes_gcm_128 aes_gcm_128;
};
struct tls_context {
union {
struct tls_crypto_info crypto_send;
struct tls12_crypto_info_aes_gcm_128 crypto_send_aes_gcm_128;
};
union {
struct tls_crypto_info crypto_recv;
struct tls12_crypto_info_aes_gcm_128 crypto_recv_aes_gcm_128;
};
union tls_crypto_context crypto_send;
union tls_crypto_context crypto_recv;
struct list_head list;
struct net_device *netdev;
......@@ -367,8 +366,8 @@ static inline void tls_fill_prepend(struct tls_context *ctx,
* size KTLS_DTLS_HEADER_SIZE + KTLS_DTLS_NONCE_EXPLICIT_SIZE
*/
buf[0] = record_type;
buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.version);
buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.version);
buf[1] = TLS_VERSION_MINOR(ctx->crypto_send.info.version);
buf[2] = TLS_VERSION_MAJOR(ctx->crypto_send.info.version);
/* we can use IV for nonce explicit according to spec */
buf[3] = pkt_len >> 8;
buf[4] = pkt_len & 0xFF;
......
......@@ -686,7 +686,7 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
goto free_marker_record;
}
crypto_info = &ctx->crypto_send;
crypto_info = &ctx->crypto_send.info;
switch (crypto_info->cipher_type) {
case TLS_CIPHER_AES_GCM_128:
nonce_size = TLS_CIPHER_AES_GCM_128_IV_SIZE;
......@@ -780,7 +780,7 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
ctx->priv_ctx_tx = offload_ctx;
rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_TX,
&ctx->crypto_send,
&ctx->crypto_send.info,
tcp_sk(sk)->write_seq);
if (rc)
goto release_netdev;
......@@ -862,7 +862,7 @@ int tls_set_device_offload_rx(struct sock *sk, struct tls_context *ctx)
goto release_ctx;
rc = netdev->tlsdev_ops->tls_dev_add(netdev, sk, TLS_OFFLOAD_CTX_DIR_RX,
&ctx->crypto_recv,
&ctx->crypto_recv.info,
tcp_sk(sk)->copied_seq);
if (rc) {
pr_err_ratelimited("%s: The netdev has refused to offload this socket\n",
......
......@@ -320,7 +320,7 @@ static struct sk_buff *tls_enc_skb(struct tls_context *tls_ctx,
goto free_req;
iv = buf;
memcpy(iv, tls_ctx->crypto_send_aes_gcm_128.salt,
memcpy(iv, tls_ctx->crypto_send.aes_gcm_128.salt,
TLS_CIPHER_AES_GCM_128_SALT_SIZE);
aad = buf + TLS_CIPHER_AES_GCM_128_SALT_SIZE +
TLS_CIPHER_AES_GCM_128_IV_SIZE;
......
......@@ -241,6 +241,16 @@ static void tls_write_space(struct sock *sk)
ctx->sk_write_space(sk);
}
static void tls_ctx_free(struct tls_context *ctx)
{
if (!ctx)
return;
memzero_explicit(&ctx->crypto_send, sizeof(ctx->crypto_send));
memzero_explicit(&ctx->crypto_recv, sizeof(ctx->crypto_recv));
kfree(ctx);
}
static void tls_sk_proto_close(struct sock *sk, long timeout)
{
struct tls_context *ctx = tls_get_ctx(sk);
......@@ -294,7 +304,7 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
#else
{
#endif
kfree(ctx);
tls_ctx_free(ctx);
ctx = NULL;
}
......@@ -305,7 +315,7 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
* for sk->sk_prot->unhash [tls_hw_unhash]
*/
if (free_ctx)
kfree(ctx);
tls_ctx_free(ctx);
}
static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
......@@ -330,7 +340,7 @@ static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
}
/* get user crypto info */
crypto_info = &ctx->crypto_send;
crypto_info = &ctx->crypto_send.info;
if (!TLS_CRYPTO_INFO_READY(crypto_info)) {
rc = -EBUSY;
......@@ -417,9 +427,9 @@ static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
}
if (tx)
crypto_info = &ctx->crypto_send;
crypto_info = &ctx->crypto_send.info;
else
crypto_info = &ctx->crypto_recv;
crypto_info = &ctx->crypto_recv.info;
/* Currently we don't support set crypto info more than one time */
if (TLS_CRYPTO_INFO_READY(crypto_info)) {
......@@ -499,7 +509,7 @@ static int do_tls_setsockopt_conf(struct sock *sk, char __user *optval,
goto out;
err_crypto_info:
memset(crypto_info, 0, sizeof(*crypto_info));
memzero_explicit(crypto_info, sizeof(union tls_crypto_context));
out:
return rc;
}
......
......@@ -1055,8 +1055,8 @@ static int tls_read_size(struct strparser *strp, struct sk_buff *skb)
goto read_failure;
}
if (header[1] != TLS_VERSION_MINOR(tls_ctx->crypto_recv.version) ||
header[2] != TLS_VERSION_MAJOR(tls_ctx->crypto_recv.version)) {
if (header[1] != TLS_VERSION_MINOR(tls_ctx->crypto_recv.info.version) ||
header[2] != TLS_VERSION_MAJOR(tls_ctx->crypto_recv.info.version)) {
ret = -EINVAL;
goto read_failure;
}
......@@ -1136,7 +1136,6 @@ void tls_sw_free_resources_rx(struct sock *sk)
int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
{
char keyval[TLS_CIPHER_AES_GCM_128_KEY_SIZE];
struct tls_crypto_info *crypto_info;
struct tls12_crypto_info_aes_gcm_128 *gcm_128_info;
struct tls_sw_context_tx *sw_ctx_tx = NULL;
......@@ -1181,12 +1180,12 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
if (tx) {
crypto_init_wait(&sw_ctx_tx->async_wait);
crypto_info = &ctx->crypto_send;
crypto_info = &ctx->crypto_send.info;
cctx = &ctx->tx;
aead = &sw_ctx_tx->aead_send;
} else {
crypto_init_wait(&sw_ctx_rx->async_wait);
crypto_info = &ctx->crypto_recv;
crypto_info = &ctx->crypto_recv.info;
cctx = &ctx->rx;
aead = &sw_ctx_rx->aead_recv;
}
......@@ -1265,9 +1264,7 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
ctx->push_pending_record = tls_sw_push_pending_record;
memcpy(keyval, gcm_128_info->key, TLS_CIPHER_AES_GCM_128_KEY_SIZE);
rc = crypto_aead_setkey(*aead, keyval,
rc = crypto_aead_setkey(*aead, gcm_128_info->key,
TLS_CIPHER_AES_GCM_128_KEY_SIZE);
if (rc)
goto free_aead;
......
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