1 files changed, 230 insertions, 130 deletions

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 31e8a94dfc11..fc88e34b7f33 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -52,6 +52,7 @@ struct tls_decrypt_arg {
 	struct_group(inargs,
 	bool zc;
 	bool async;
+	bool async_done;
 	u8 tail;
 	);
 
@@ -63,6 +64,7 @@ struct tls_decrypt_ctx {
 	u8 iv[TLS_MAX_IV_SIZE];
 	u8 aad[TLS_MAX_AAD_SIZE];
 	u8 tail;
+	bool free_sgout;
 	struct scatterlist sg[];
 };
 
@@ -187,7 +189,6 @@ static void tls_decrypt_done(void *data, int err)
 	struct aead_request *aead_req = data;
 	struct crypto_aead *aead = crypto_aead_reqtfm(aead_req);
 	struct scatterlist *sgout = aead_req->dst;
-	struct scatterlist *sgin = aead_req->src;
 	struct tls_sw_context_rx *ctx;
 	struct tls_decrypt_ctx *dctx;
 	struct tls_context *tls_ctx;
@@ -196,6 +197,17 @@ static void tls_decrypt_done(void *data, int err)
 	struct sock *sk;
 	int aead_size;
 
+	/* If requests get too backlogged crypto API returns -EBUSY and calls
+	 * ->complete(-EINPROGRESS) immediately followed by ->complete(0)
+	 * to make waiting for backlog to flush with crypto_wait_req() easier.
+	 * First wait converts -EBUSY -> -EINPROGRESS, and the second one
+	 * -EINPROGRESS -> 0.
+	 * We have a single struct crypto_async_request per direction, this
+	 * scheme doesn't help us, so just ignore the first ->complete().
+	 */
+	if (err == -EINPROGRESS)
+		return;
+
 	aead_size = sizeof(*aead_req) + crypto_aead_reqsize(aead);
 	aead_size = ALIGN(aead_size, __alignof__(*dctx));
 	dctx = (void *)((u8 *)aead_req + aead_size);
@@ -213,7 +225,7 @@ static void tls_decrypt_done(void *data, int err)
 	}
 
 	/* Free the destination pages if skb was not decrypted inplace */
-	if (sgout != sgin) {
+	if (dctx->free_sgout) {
 		/* Skip the first S/G entry as it points to AAD */
 		for_each_sg(sg_next(sgout), sg, UINT_MAX, pages) {
 			if (!sg)
@@ -224,10 +236,17 @@ static void tls_decrypt_done(void *data, int err)
 
 	kfree(aead_req);
 
-	spin_lock_bh(&ctx->decrypt_compl_lock);
-	if (!atomic_dec_return(&ctx->decrypt_pending))
+	if (atomic_dec_and_test(&ctx->decrypt_pending))
 		complete(&ctx->async_wait.completion);
-	spin_unlock_bh(&ctx->decrypt_compl_lock);
+}
+
+static int tls_decrypt_async_wait(struct tls_sw_context_rx *ctx)
+{
+	if (!atomic_dec_and_test(&ctx->decrypt_pending))
+		crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
+	atomic_inc(&ctx->decrypt_pending);
+
+	return ctx->async_wait.err;
 }
 
 static int tls_do_decryption(struct sock *sk,
@@ -253,20 +272,33 @@ static int tls_do_decryption(struct sock *sk,
 		aead_request_set_callback(aead_req,
 					  CRYPTO_TFM_REQ_MAY_BACKLOG,
 					  tls_decrypt_done, aead_req);
+		DEBUG_NET_WARN_ON_ONCE(atomic_read(&ctx->decrypt_pending) < 1);
 		atomic_inc(&ctx->decrypt_pending);
 	} else {
+		DECLARE_CRYPTO_WAIT(wait);
+
 		aead_request_set_callback(aead_req,
 					  CRYPTO_TFM_REQ_MAY_BACKLOG,
-					  crypto_req_done, &ctx->async_wait);
+					  crypto_req_done, &wait);
+		ret = crypto_aead_decrypt(aead_req);
+		if (ret == -EINPROGRESS || ret == -EBUSY)
+			ret = crypto_wait_req(ret, &wait);
+		return ret;
 	}
 
 	ret = crypto_aead_decrypt(aead_req);
-	if (ret == -EINPROGRESS) {
-		if (darg->async)
-			return 0;
+	if (ret == -EINPROGRESS)
+		return 0;
 
-		ret = crypto_wait_req(ret, &ctx->async_wait);
+	if (ret == -EBUSY) {
+		ret = tls_decrypt_async_wait(ctx);
+		darg->async_done = true;
+		/* all completions have run, we're not doing async anymore */
+		darg->async = false;
+		return ret;
 	}
+
+	atomic_dec(&ctx->decrypt_pending);
 	darg->async = false;
 
 	return ret;
@@ -426,7 +458,7 @@ int tls_tx_records(struct sock *sk, int flags)
 
 tx_err:
 	if (rc < 0 && rc != -EAGAIN)
-		tls_err_abort(sk, -EBADMSG);
+		tls_err_abort(sk, rc);
 
 	return rc;
 }
@@ -439,9 +471,10 @@ static void tls_encrypt_done(void *data, int err)
 	struct tls_rec *rec = data;
 	struct scatterlist *sge;
 	struct sk_msg *msg_en;
-	bool ready = false;
 	struct sock *sk;
-	int pending;
+
+	if (err == -EINPROGRESS) /* see the comment in tls_decrypt_done() */
+		return;
 
 	msg_en = &rec->msg_encrypted;
 
@@ -476,23 +509,25 @@ static void tls_encrypt_done(void *data, int err)
 		/* If received record is at head of tx_list, schedule tx */
 		first_rec = list_first_entry(&ctx->tx_list,
 					     struct tls_rec, list);
-		if (rec == first_rec)
-			ready = true;
+		if (rec == first_rec) {
+			/* Schedule the transmission */
+			if (!test_and_set_bit(BIT_TX_SCHEDULED,
+					      &ctx->tx_bitmask))
+				schedule_delayed_work(&ctx->tx_work.work, 1);
+		}
 	}
 
-	spin_lock_bh(&ctx->encrypt_compl_lock);
-	pending = atomic_dec_return(&ctx->encrypt_pending);
-
-	if (!pending && ctx->async_notify)
+	if (atomic_dec_and_test(&ctx->encrypt_pending))
 		complete(&ctx->async_wait.completion);
-	spin_unlock_bh(&ctx->encrypt_compl_lock);
+}
 
-	if (!ready)
-		return;
+static int tls_encrypt_async_wait(struct tls_sw_context_tx *ctx)
+{
+	if (!atomic_dec_and_test(&ctx->encrypt_pending))
+		crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
+	atomic_inc(&ctx->encrypt_pending);
 
-	/* Schedule the transmission */
-	if (!test_and_set_bit(BIT_TX_SCHEDULED, &ctx->tx_bitmask))
-		schedule_delayed_work(&ctx->tx_work.work, 1);
+	return ctx->async_wait.err;
 }
 
 static int tls_do_encryption(struct sock *sk,
@@ -541,9 +576,14 @@ static int tls_do_encryption(struct sock *sk,
 
 	/* Add the record in tx_list */
 	list_add_tail((struct list_head *)&rec->list, &ctx->tx_list);
+	DEBUG_NET_WARN_ON_ONCE(atomic_read(&ctx->encrypt_pending) < 1);
 	atomic_inc(&ctx->encrypt_pending);
 
 	rc = crypto_aead_encrypt(aead_req);
+	if (rc == -EBUSY) {
+		rc = tls_encrypt_async_wait(ctx);
+		rc = rc ?: -EINPROGRESS;
+	}
 	if (!rc || rc != -EINPROGRESS) {
 		atomic_dec(&ctx->encrypt_pending);
 		sge->offset -= prot->prepend_size;
@@ -868,6 +908,13 @@ more_data:
 					    &msg_redir, send, flags);
 		lock_sock(sk);
 		if (err < 0) {
+			/* Regardless of whether the data represented by
+			 * msg_redir is sent successfully, we have already
+			 * uncharged it via sk_msg_return_zero(). The
+			 * msg->sg.size represents the remaining unprocessed
+			 * data, which needs to be uncharged here.
+			 */
+			sk_mem_uncharge(sk, msg->sg.size);
 			*copied -= sk_msg_free_nocharge(sk, &msg_redir);
 			msg->sg.size = 0;
 		}
@@ -984,7 +1031,6 @@ static int tls_sw_sendmsg_locked(struct sock *sk, struct msghdr *msg,
 	int num_zc = 0;
 	int orig_size;
 	int ret = 0;
-	int pending;
 
 	if (!eor && (msg->msg_flags & MSG_EOR))
 		return -EINVAL;
@@ -1081,9 +1127,13 @@ alloc_encrypted:
 					num_async++;
 				else if (ret == -ENOMEM)
 					goto wait_for_memory;
-				else if (ctx->open_rec && ret == -ENOSPC)
+				else if (ctx->open_rec && ret == -ENOSPC) {
+					if (msg_pl->cork_bytes) {
+						ret = 0;
+						goto send_end;
+					}
 					goto rollback_iter;
-				else if (ret != -EAGAIN)
+				} else if (ret != -EAGAIN)
 					goto send_end;
 			}
 			continue;
@@ -1162,25 +1212,13 @@ trim_sgl:
 
 	if (!num_async) {
 		goto send_end;
-	} else if (num_zc) {
-		/* Wait for pending encryptions to get completed */
-		spin_lock_bh(&ctx->encrypt_compl_lock);
-		ctx->async_notify = true;
-
-		pending = atomic_read(&ctx->encrypt_pending);
-		spin_unlock_bh(&ctx->encrypt_compl_lock);
-		if (pending)
-			crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
-		else
-			reinit_completion(&ctx->async_wait.completion);
-
-		/* There can be no concurrent accesses, since we have no
-		 * pending encrypt operations
-		 */
-		WRITE_ONCE(ctx->async_notify, false);
+	} else if (num_zc || eor) {
+		int err;
 
-		if (ctx->async_wait.err) {
-			ret = ctx->async_wait.err;
+		/* Wait for pending encryptions to get completed */
+		err = tls_encrypt_async_wait(ctx);
+		if (err) {
+			ret = err;
 			copied = 0;
 		}
 	}
@@ -1229,7 +1267,6 @@ void tls_sw_splice_eof(struct socket *sock)
 	ssize_t copied = 0;
 	bool retrying = false;
 	int ret = 0;
-	int pending;
 
 	if (!ctx->open_rec)
 		return;
@@ -1264,22 +1301,7 @@ retry:
 	}
 
 	/* Wait for pending encryptions to get completed */
-	spin_lock_bh(&ctx->encrypt_compl_lock);
-	ctx->async_notify = true;
-
-	pending = atomic_read(&ctx->encrypt_pending);
-	spin_unlock_bh(&ctx->encrypt_compl_lock);
-	if (pending)
-		crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
-	else
-		reinit_completion(&ctx->async_wait.completion);
-
-	/* There can be no concurrent accesses, since we have no pending
-	 * encrypt operations
-	 */
-	WRITE_ONCE(ctx->async_notify, false);
-
-	if (ctx->async_wait.err)
+	if (tls_encrypt_async_wait(ctx))
 		goto unlock;
 
 	/* Transmit if any encryptions have completed */
@@ -1303,6 +1325,10 @@ tls_rx_rec_wait(struct sock *sk, struct sk_psock *psock, bool nonblock,
 	int ret = 0;
 	long timeo;
 
+	/* a rekey is pending, let userspace deal with it */
+	if (unlikely(ctx->key_update_pending))
+		return -EKEYEXPIRED;
+
 	timeo = sock_rcvtimeo(sk, nonblock);
 
 	while (!tls_strp_msg_ready(ctx)) {
@@ -1581,12 +1607,16 @@ static int tls_decrypt_sg(struct sock *sk, struct iov_iter *out_iov,
 	} else if (out_sg) {
 		memcpy(sgout, out_sg, n_sgout * sizeof(*sgout));
 	}
+	dctx->free_sgout = !!pages;
 
 	/* Prepare and submit AEAD request */
 	err = tls_do_decryption(sk, sgin, sgout, dctx->iv,
 				data_len + prot->tail_size, aead_req, darg);
-	if (err)
+	if (err) {
+		if (darg->async_done)
+			goto exit_free_skb;
 		goto exit_free_pages;
+	}
 
 	darg->skb = clear_skb ?: tls_strp_msg(ctx);
 	clear_skb = NULL;
@@ -1598,6 +1628,9 @@ static int tls_decrypt_sg(struct sock *sk, struct iov_iter *out_iov,
 		return err;
 	}
 
+	if (unlikely(darg->async_done))
+		return 0;
+
 	if (prot->tail_size)
 		darg->tail = dctx->tail;
 
@@ -1702,6 +1735,36 @@ tls_decrypt_device(struct sock *sk, struct msghdr *msg,
 	return 1;
 }
 
+static int tls_check_pending_rekey(struct sock *sk, struct tls_context *ctx,
+				   struct sk_buff *skb)
+{
+	const struct strp_msg *rxm = strp_msg(skb);
+	const struct tls_msg *tlm = tls_msg(skb);
+	char hs_type;
+	int err;
+
+	if (likely(tlm->control != TLS_RECORD_TYPE_HANDSHAKE))
+		return 0;
+
+	if (rxm->full_len < 1)
+		return 0;
+
+	err = skb_copy_bits(skb, rxm->offset, &hs_type, 1);
+	if (err < 0) {
+		DEBUG_NET_WARN_ON_ONCE(1);
+		return err;
+	}
+
+	if (hs_type == TLS_HANDSHAKE_KEYUPDATE) {
+		struct tls_sw_context_rx *rx_ctx = ctx->priv_ctx_rx;
+
+		WRITE_ONCE(rx_ctx->key_update_pending, true);
+		TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXREKEYRECEIVED);
+	}
+
+	return 0;
+}
+
 static int tls_rx_one_record(struct sock *sk, struct msghdr *msg,
 			     struct tls_decrypt_arg *darg)
 {
@@ -1721,7 +1784,7 @@ static int tls_rx_one_record(struct sock *sk, struct msghdr *msg,
 	rxm->full_len -= prot->overhead_size;
 	tls_advance_record_sn(sk, prot, &tls_ctx->rx);
 
-	return 0;
+	return tls_check_pending_rekey(sk, tls_ctx, darg->skb);
 }
 
 int decrypt_skb(struct sock *sk, struct scatterlist *sgout)
@@ -1769,7 +1832,8 @@ static int process_rx_list(struct tls_sw_context_rx *ctx,
 			   u8 *control,
 			   size_t skip,
 			   size_t len,
-			   bool is_peek)
+			   bool is_peek,
+			   bool *more)
 {
 	struct sk_buff *skb = skb_peek(&ctx->rx_list);
 	struct tls_msg *tlm;
@@ -1782,7 +1846,7 @@ static int process_rx_list(struct tls_sw_context_rx *ctx,
 
 		err = tls_record_content_type(msg, tlm, control);
 		if (err <= 0)
-			goto out;
+			goto more;
 
 		if (skip < rxm->full_len)
 			break;
@@ -1800,12 +1864,12 @@ static int process_rx_list(struct tls_sw_context_rx *ctx,
 
 		err = tls_record_content_type(msg, tlm, control);
 		if (err <= 0)
-			goto out;
+			goto more;
 
 		err = skb_copy_datagram_msg(skb, rxm->offset + skip,
 					    msg, chunk);
 		if (err < 0)
-			goto out;
+			goto more;
 
 		len = len - chunk;
 		copied = copied + chunk;
@@ -1841,6 +1905,10 @@ static int process_rx_list(struct tls_sw_context_rx *ctx,
 
 out:
 	return copied ? : err;
+more:
+	if (more)
+		*more = true;
+	goto out;
 }
 
 static bool
@@ -1940,10 +2008,12 @@ int tls_sw_recvmsg(struct sock *sk,
 	struct strp_msg *rxm;
 	struct tls_msg *tlm;
 	ssize_t copied = 0;
+	ssize_t peeked = 0;
 	bool async = false;
 	int target, err;
 	bool is_kvec = iov_iter_is_kvec(&msg->msg_iter);
 	bool is_peek = flags & MSG_PEEK;
+	bool rx_more = false;
 	bool released = true;
 	bool bpf_strp_enabled;
 	bool zc_capable;
@@ -1951,10 +2021,10 @@ int tls_sw_recvmsg(struct sock *sk,
 	if (unlikely(flags & MSG_ERRQUEUE))
 		return sock_recv_errqueue(sk, msg, len, SOL_IP, IP_RECVERR);
 
-	psock = sk_psock_get(sk);
 	err = tls_rx_reader_lock(sk, ctx, flags & MSG_DONTWAIT);
 	if (err < 0)
 		return err;
+	psock = sk_psock_get(sk);
 	bpf_strp_enabled = sk_psock_strp_enabled(psock);
 
 	/* If crypto failed the connection is broken */
@@ -1963,12 +2033,12 @@ int tls_sw_recvmsg(struct sock *sk,
 		goto end;
 
 	/* Process pending decrypted records. It must be non-zero-copy */
-	err = process_rx_list(ctx, msg, &control, 0, len, is_peek);
+	err = process_rx_list(ctx, msg, &control, 0, len, is_peek, &rx_more);
 	if (err < 0)
 		goto end;
 
 	copied = err;
-	if (len <= copied)
+	if (len <= copied || (copied && control != TLS_RECORD_TYPE_DATA) || rx_more)
 		goto end;
 
 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
@@ -2061,6 +2131,8 @@ put_on_rx_list:
 				decrypted += chunk;
 				len -= chunk;
 				__skb_queue_tail(&ctx->rx_list, skb);
+				if (unlikely(control != TLS_RECORD_TYPE_DATA))
+					break;
 				continue;
 			}
 
@@ -2084,8 +2156,10 @@ put_on_rx_list:
 			if (err < 0)
 				goto put_on_rx_list_err;
 
-			if (is_peek)
+			if (is_peek) {
+				peeked += chunk;
 				goto put_on_rx_list;
+			}
 
 			if (partially_consumed) {
 				rxm->offset += chunk;
@@ -2109,33 +2183,28 @@ put_on_rx_list:
 
 recv_end:
 	if (async) {
-		int ret, pending;
+		int ret;
 
 		/* Wait for all previously submitted records to be decrypted */
-		spin_lock_bh(&ctx->decrypt_compl_lock);
-		reinit_completion(&ctx->async_wait.completion);
-		pending = atomic_read(&ctx->decrypt_pending);
-		spin_unlock_bh(&ctx->decrypt_compl_lock);
-		ret = 0;
-		if (pending)
-			ret = crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
+		ret = tls_decrypt_async_wait(ctx);
 		__skb_queue_purge(&ctx->async_hold);
 
 		if (ret) {
 			if (err >= 0 || err == -EINPROGRESS)
 				err = ret;
-			decrypted = 0;
 			goto end;
 		}
 
 		/* Drain records from the rx_list & copy if required */
-		if (is_peek || is_kvec)
-			err = process_rx_list(ctx, msg, &control, copied,
-					      decrypted, is_peek);
+		if (is_peek)
+			err = process_rx_list(ctx, msg, &control, copied + peeked,
+					      decrypted - peeked, is_peek, NULL);
 		else
 			err = process_rx_list(ctx, msg, &control, 0,
-					      async_copy_bytes, is_peek);
-		decrypted += max(err, 0);
+					      async_copy_bytes, is_peek, NULL);
+
+		/* we could have copied less than we wanted, and possibly nothing */
+		decrypted += max(err, 0) - async_copy_bytes;
 	}
 
 	copied += decrypted;
@@ -2435,16 +2504,9 @@ void tls_sw_release_resources_tx(struct sock *sk)
 	struct tls_context *tls_ctx = tls_get_ctx(sk);
 	struct tls_sw_context_tx *ctx = tls_sw_ctx_tx(tls_ctx);
 	struct tls_rec *rec, *tmp;
-	int pending;
 
 	/* Wait for any pending async encryptions to complete */
-	spin_lock_bh(&ctx->encrypt_compl_lock);
-	ctx->async_notify = true;
-	pending = atomic_read(&ctx->encrypt_pending);
-	spin_unlock_bh(&ctx->encrypt_compl_lock);
-
-	if (pending)
-		crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
+	tls_encrypt_async_wait(ctx);
 
 	tls_tx_records(sk, -1);
 
@@ -2607,7 +2669,7 @@ static struct tls_sw_context_tx *init_ctx_tx(struct tls_context *ctx, struct soc
 	}
 
 	crypto_init_wait(&sw_ctx_tx->async_wait);
-	spin_lock_init(&sw_ctx_tx->encrypt_compl_lock);
+	atomic_set(&sw_ctx_tx->encrypt_pending, 1);
 	INIT_LIST_HEAD(&sw_ctx_tx->tx_list);
 	INIT_DELAYED_WORK(&sw_ctx_tx->tx_work.work, tx_work_handler);
 	sw_ctx_tx->tx_work.sk = sk;
@@ -2628,7 +2690,7 @@ static struct tls_sw_context_rx *init_ctx_rx(struct tls_context *ctx)
 	}
 
 	crypto_init_wait(&sw_ctx_rx->async_wait);
-	spin_lock_init(&sw_ctx_rx->decrypt_compl_lock);
+	atomic_set(&sw_ctx_rx->decrypt_pending, 1);
 	init_waitqueue_head(&sw_ctx_rx->wq);
 	skb_queue_head_init(&sw_ctx_rx->rx_list);
 	skb_queue_head_init(&sw_ctx_rx->async_hold);
@@ -2667,12 +2729,22 @@ int init_prot_info(struct tls_prot_info *prot,
 	return 0;
 }
 
-int tls_set_sw_offload(struct sock *sk, int tx)
+static void tls_finish_key_update(struct sock *sk, struct tls_context *tls_ctx)
+{
+	struct tls_sw_context_rx *ctx = tls_ctx->priv_ctx_rx;
+
+	WRITE_ONCE(ctx->key_update_pending, false);
+	/* wake-up pre-existing poll() */
+	ctx->saved_data_ready(sk);
+}
+
+int tls_set_sw_offload(struct sock *sk, int tx,
+		       struct tls_crypto_info *new_crypto_info)
 {
+	struct tls_crypto_info *crypto_info, *src_crypto_info;
 	struct tls_sw_context_tx *sw_ctx_tx = NULL;
 	struct tls_sw_context_rx *sw_ctx_rx = NULL;
 	const struct tls_cipher_desc *cipher_desc;
-	struct tls_crypto_info *crypto_info;
 	char *iv, *rec_seq, *key, *salt;
 	struct cipher_context *cctx;
 	struct tls_prot_info *prot;
@@ -2684,44 +2756,47 @@ int tls_set_sw_offload(struct sock *sk, int tx)
 	ctx = tls_get_ctx(sk);
 	prot = &ctx->prot_info;
 
-	if (tx) {
-		ctx->priv_ctx_tx = init_ctx_tx(ctx, sk);
-		if (!ctx->priv_ctx_tx)
-			return -ENOMEM;
+	/* new_crypto_info != NULL means rekey */
+	if (!new_crypto_info) {
+		if (tx) {
+			ctx->priv_ctx_tx = init_ctx_tx(ctx, sk);
+			if (!ctx->priv_ctx_tx)
+				return -ENOMEM;
+		} else {
+			ctx->priv_ctx_rx = init_ctx_rx(ctx);
+			if (!ctx->priv_ctx_rx)
+				return -ENOMEM;
+		}
+	}
 
+	if (tx) {
 		sw_ctx_tx = ctx->priv_ctx_tx;
 		crypto_info = &ctx->crypto_send.info;
 		cctx = &ctx->tx;
 		aead = &sw_ctx_tx->aead_send;
 	} else {
-		ctx->priv_ctx_rx = init_ctx_rx(ctx);
-		if (!ctx->priv_ctx_rx)
-			return -ENOMEM;
-
 		sw_ctx_rx = ctx->priv_ctx_rx;
 		crypto_info = &ctx->crypto_recv.info;
 		cctx = &ctx->rx;
 		aead = &sw_ctx_rx->aead_recv;
 	}
 
-	cipher_desc = get_cipher_desc(crypto_info->cipher_type);
+	src_crypto_info = new_crypto_info ?: crypto_info;
+
+	cipher_desc = get_cipher_desc(src_crypto_info->cipher_type);
 	if (!cipher_desc) {
 		rc = -EINVAL;
 		goto free_priv;
 	}
 
-	rc = init_prot_info(prot, crypto_info, cipher_desc);
+	rc = init_prot_info(prot, src_crypto_info, cipher_desc);
 	if (rc)
 		goto free_priv;
 
-	iv = crypto_info_iv(crypto_info, cipher_desc);
-	key = crypto_info_key(crypto_info, cipher_desc);
-	salt = crypto_info_salt(crypto_info, cipher_desc);
-	rec_seq = crypto_info_rec_seq(crypto_info, cipher_desc);
-
-	memcpy(cctx->iv, salt, cipher_desc->salt);
-	memcpy(cctx->iv + cipher_desc->salt, iv, cipher_desc->iv);
-	memcpy(cctx->rec_seq, rec_seq, cipher_desc->rec_seq);
+	iv = crypto_info_iv(src_crypto_info, cipher_desc);
+	key = crypto_info_key(src_crypto_info, cipher_desc);
+	salt = crypto_info_salt(src_crypto_info, cipher_desc);
+	rec_seq = crypto_info_rec_seq(src_crypto_info, cipher_desc);
 
 	if (!*aead) {
 		*aead = crypto_alloc_aead(cipher_desc->cipher_name, 0, 0);
@@ -2734,20 +2809,30 @@ int tls_set_sw_offload(struct sock *sk, int tx)
 
 	ctx->push_pending_record = tls_sw_push_pending_record;
 
+	/* setkey is the last operation that could fail during a
+	 * rekey. if it succeeds, we can start modifying the
+	 * context.
+	 */
 	rc = crypto_aead_setkey(*aead, key, cipher_desc->key);
-	if (rc)
-		goto free_aead;
+	if (rc) {
+		if (new_crypto_info)
+			goto out;
+		else
+			goto free_aead;
+	}
 
-	rc = crypto_aead_setauthsize(*aead, prot->tag_size);
-	if (rc)
-		goto free_aead;
+	if (!new_crypto_info) {
+		rc = crypto_aead_setauthsize(*aead, prot->tag_size);
+		if (rc)
+			goto free_aead;
+	}
 
-	if (sw_ctx_rx) {
+	if (!tx && !new_crypto_info) {
 		tfm = crypto_aead_tfm(sw_ctx_rx->aead_recv);
 
 		tls_update_rx_zc_capable(ctx);
 		sw_ctx_rx->async_capable =
-			crypto_info->version != TLS_1_3_VERSION &&
+			src_crypto_info->version != TLS_1_3_VERSION &&
 			!!(tfm->__crt_alg->cra_flags & CRYPTO_ALG_ASYNC);
 
 		rc = tls_strp_init(&sw_ctx_rx->strp, sk);
@@ -2755,18 +2840,33 @@ int tls_set_sw_offload(struct sock *sk, int tx)
 			goto free_aead;
 	}
 
+	memcpy(cctx->iv, salt, cipher_desc->salt);
+	memcpy(cctx->iv + cipher_desc->salt, iv, cipher_desc->iv);
+	memcpy(cctx->rec_seq, rec_seq, cipher_desc->rec_seq);
+
+	if (new_crypto_info) {
+		unsafe_memcpy(crypto_info, new_crypto_info,
+			      cipher_desc->crypto_info,
+			      /* size was checked in do_tls_setsockopt_conf */);
+		memzero_explicit(new_crypto_info, cipher_desc->crypto_info);
+		if (!tx)
+			tls_finish_key_update(sk, ctx);
+	}
+
 	goto out;
 
 free_aead:
 	crypto_free_aead(*aead);
 	*aead = NULL;
 free_priv:
-	if (tx) {
-		kfree(ctx->priv_ctx_tx);
-		ctx->priv_ctx_tx = NULL;
-	} else {
-		kfree(ctx->priv_ctx_rx);
-		ctx->priv_ctx_rx = NULL;
+	if (!new_crypto_info) {
+		if (tx) {
+			kfree(ctx->priv_ctx_tx);
+			ctx->priv_ctx_tx = NULL;
+		} else {
+			kfree(ctx->priv_ctx_rx);
+			ctx->priv_ctx_rx = NULL;
+		}
 	}
 out:
 	return rc;