diff options
| author | Ilya Lesokhin <ilyal@mellanox.com> | 2017-11-13 10:22:48 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-11-14 16:26:34 +0900 |
| commit | 196c31b4b54474b31dee3c30352c45c2a93e9226 (patch) | |
| tree | 41b97d82a0c7f81a832da89c798dc0d470cd237c /net/tls | |
| parent | 213ef6e7c9c063c482d77f12cc438872628d48ec (diff) | |
tls: Avoid copying crypto_info again after cipher_type check.
Avoid copying crypto_info again after cipher_type check
to avoid a TOCTOU exploits.
The temporary array on the stack is removed as we don't really need it
Fixes: 3c4d7559159b ('tls: kernel TLS support')
Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tls')
| -rw-r--r-- | net/tls/tls_main.c | 29 |
1 files changed, 12 insertions, 17 deletions
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c index 13427ee7c582..ab1bd167b63b 100644 --- a/net/tls/tls_main.c +++ b/net/tls/tls_main.c @@ -355,7 +355,7 @@ static int tls_getsockopt(struct sock *sk, int level, int optname, static int do_tls_setsockopt_tx(struct sock *sk, char __user *optval, unsigned int optlen) { - struct tls_crypto_info *crypto_info, tmp_crypto_info; + struct tls_crypto_info *crypto_info; struct tls_context *ctx = tls_get_ctx(sk); int rc = 0; int tx_conf; @@ -365,36 +365,31 @@ static int do_tls_setsockopt_tx(struct sock *sk, char __user *optval, goto out; } - rc = copy_from_user(&tmp_crypto_info, optval, sizeof(*crypto_info)); + crypto_info = &ctx->crypto_send; + /* Currently we don't support set crypto info more than one time */ + if (TLS_CRYPTO_INFO_READY(crypto_info)) + goto out; + + rc = copy_from_user(crypto_info, optval, sizeof(*crypto_info)); if (rc) { rc = -EFAULT; goto out; } /* check version */ - if (tmp_crypto_info.version != TLS_1_2_VERSION) { + if (crypto_info->version != TLS_1_2_VERSION) { rc = -ENOTSUPP; - goto out; + goto err_crypto_info; } - /* get user crypto info */ - crypto_info = &ctx->crypto_send; - - /* Currently we don't support set crypto info more than one time */ - if (TLS_CRYPTO_INFO_READY(crypto_info)) - goto out; - - switch (tmp_crypto_info.cipher_type) { + switch (crypto_info->cipher_type) { case TLS_CIPHER_AES_GCM_128: { if (optlen != sizeof(struct tls12_crypto_info_aes_gcm_128)) { rc = -EINVAL; goto out; } - rc = copy_from_user( - crypto_info, - optval, - sizeof(struct tls12_crypto_info_aes_gcm_128)); - + rc = copy_from_user(crypto_info + 1, optval + sizeof(*crypto_info), + optlen - sizeof(*crypto_info)); if (rc) { rc = -EFAULT; goto err_crypto_info; |