tls: store rec_seq directly within cipher_context

TLS_MAX_REC_SEQ_SIZE is 8B, we don't get anything by using kmalloc.
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/tls.h

@@ -194,7 +194,7 @@ enum tls_context_flags {
 
 struct cipher_context {
 	char *iv;
-	char *rec_seq;
+	char rec_seq[TLS_MAX_REC_SEQ_SIZE];
 };
 
 union tls_crypto_context {

net/tls/tls_device.c

@@ -58,7 +58,6 @@ static void tls_device_free_ctx(struct tls_context *ctx)
 {
 	if (ctx->tx_conf == TLS_HW) {
 		kfree(tls_offload_ctx_tx(ctx));
-		kfree(ctx->tx.rec_seq);
 		kfree(ctx->tx.iv);
 	}
 
@@ -1098,16 +1097,12 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
 	memcpy(ctx->tx.iv + cipher_desc->salt, iv, cipher_desc->iv);
 
 	prot->rec_seq_size = cipher_desc->rec_seq;
-	ctx->tx.rec_seq = kmemdup(rec_seq, cipher_desc->rec_seq, GFP_KERNEL);
-	if (!ctx->tx.rec_seq) {
-		rc = -ENOMEM;
-		goto free_iv;
-	}
+	memcpy(ctx->tx.rec_seq, rec_seq, cipher_desc->rec_seq);
 
 	start_marker_record = kmalloc(sizeof(*start_marker_record), GFP_KERNEL);
 	if (!start_marker_record) {
 		rc = -ENOMEM;
-		goto free_rec_seq;
+		goto free_iv;
 	}
 
 	offload_ctx = kzalloc(TLS_OFFLOAD_CONTEXT_SIZE_TX, GFP_KERNEL);
@@ -1192,8 +1187,6 @@ int tls_set_device_offload(struct sock *sk, struct tls_context *ctx)
 	ctx->priv_ctx_tx = NULL;
 free_marker_record:
 	kfree(start_marker_record);
-free_rec_seq:
-	kfree(ctx->tx.rec_seq);
 free_iv:
 	kfree(ctx->tx.iv);
 release_netdev:

net/tls/tls_main.c

@@ -344,7 +344,6 @@ static void tls_sk_proto_cleanup(struct sock *sk,
 
 	/* We need these for tls_sw_fallback handling of other packets */
 	if (ctx->tx_conf == TLS_SW) {
-		kfree(ctx->tx.rec_seq);
 		kfree(ctx->tx.iv);
 		tls_sw_release_resources_tx(sk);
 		TLS_DEC_STATS(sock_net(sk), LINUX_MIB_TLSCURRTXSW);

net/tls/tls_sw.c

@@ -2467,7 +2467,6 @@ void tls_sw_release_resources_rx(struct sock *sk)
 	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct tls_sw_context_rx *ctx = tls_sw_ctx_rx(tls_ctx);
 
-	kfree(tls_ctx->rx.rec_seq);
 	kfree(tls_ctx->rx.iv);
 
 	if (ctx->aead_recv) {
@@ -2692,19 +2691,14 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
 	prot->rec_seq_size = cipher_desc->rec_seq;
 	memcpy(cctx->iv, salt, cipher_desc->salt);
 	memcpy(cctx->iv + cipher_desc->salt, iv, cipher_desc->iv);
-
-	cctx->rec_seq = kmemdup(rec_seq, cipher_desc->rec_seq, GFP_KERNEL);
-	if (!cctx->rec_seq) {
-		rc = -ENOMEM;
-		goto free_iv;
-	}
+	memcpy(cctx->rec_seq, rec_seq, cipher_desc->rec_seq);
 
 	if (!*aead) {
 		*aead = crypto_alloc_aead(cipher_desc->cipher_name, 0, 0);
 		if (IS_ERR(*aead)) {
 			rc = PTR_ERR(*aead);
 			*aead = NULL;
-			goto free_rec_seq;
+			goto free_iv;
 		}
 	}
 
@@ -2736,9 +2730,6 @@ int tls_set_sw_offload(struct sock *sk, struct tls_context *ctx, int tx)
 free_aead:
 	crypto_free_aead(*aead);
 	*aead = NULL;
-free_rec_seq:
-	kfree(cctx->rec_seq);
-	cctx->rec_seq = NULL;
 free_iv:
 	kfree(cctx->iv);
 	cctx->iv = NULL;