4.14-stable review patch. If anyone has any objections, please let me know.
------------------
commit 196c31b4b54474b31dee3c30352c45c2a93e9226 upstream.
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@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[bwh: Backported to 4.14: Preserve changes made by earlier backports of
"tls: return -EBUSY if crypto_info is already set" and "tls: zero the
crypto information from tls_context before freeing"]
Signed-off-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/tls/tls_main.c | 33 ++++++++++++++-------------------
1 file changed, 14 insertions(+), 19 deletions(-)
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index b5f9c578bcf0..f88df514ad5f 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -381,7 +381,7 @@ 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;
@@ -391,38 +391,33 @@ 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.info;
+ /* Currently we don't support set crypto info more than one time */
+ if (TLS_CRYPTO_INFO_READY(crypto_info)) {
+ rc = -EBUSY;
+ 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;
- }
-
- /* get user crypto info */
- crypto_info = &ctx->crypto_send.info;
-
- /* Currently we don't support set crypto info more than one time */
- if (TLS_CRYPTO_INFO_READY(crypto_info)) {
- rc = -EBUSY;
- goto out;
+ goto err_crypto_info;
}
- 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 err_crypto_info;
}
- 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;
--
2.17.1
