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tls: zero the crypto information from tls_context before freeing

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[ Upstream commit 86029d10af18381814881d6cce2dd6872163b59f ]

This contains key material in crypto_send_aes_gcm_128 and
crypto_recv_aes_gcm_128.

Introduce union tls_crypto_context, and replace the two identical
unions directly embedded in struct tls_context with it. We can then
use this union to clean up the memory in the new tls_ctx_free()
function.

Fixes: 3c4d7559159b ("tls: kernel TLS support")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sabrina Dubroca 2018-09-12 17:44:42 +02:00 committed by Greg Kroah-Hartman
parent 10cacaf131
commit 0c0334299a
3 changed files with 21 additions and 10 deletions
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14
include/net/tls.h
View File

@ -79,11 +79,13 @@ enum {
TLS_PENDING_CLOSED_RECORD
};
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 tls_crypto_context crypto_send;
void *priv_ctx;
@ -208,8 +210,8 @@ 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;

15
net/tls/tls_main.c
View File

@ -218,6 +218,15 @@ 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));
kfree(ctx);
}
static void tls_sk_proto_close(struct sock *sk, long timeout)
{
struct tls_context *ctx = tls_get_ctx(sk);
@ -246,7 +255,7 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
kfree(ctx->iv);
sk_proto_close = ctx->sk_proto_close;
kfree(ctx);
tls_ctx_free(ctx);
release_sock(sk);
sk_proto_close(sk, timeout);
@ -274,7 +283,7 @@ 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;
@ -371,7 +380,7 @@ static int do_tls_setsockopt_tx(struct sock *sk, char __user *optval,
}
/* get user crypto info */
crypto_info = &ctx->crypto_send;
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)) {

2
net/tls/tls_sw.c
View File

@ -687,7 +687,7 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx)
ctx->priv_ctx = (struct tls_offload_context *)sw_ctx;
ctx->free_resources = tls_sw_free_resources;
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;