| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <bebf00fb-be2d-d6da-bd7f-4e610095decc@suse.de>
Date: Mon, 14 Aug 2023 16:03:12 +0200
From: Hannes Reinecke <hare@...e.de>
To: Sagi Grimberg <sagi@...mberg.me>, Christoph Hellwig <hch@....de>
Cc: Keith Busch <kbusch@...nel.org>, linux-nvme@...ts.infradead.org,
Jakub Kicinski <kuba@...nel.org>, Eric Dumazet <edumazet@...gle.com>,
Paolo Abeni <pabeni@...hat.com>, netdev@...r.kernel.org
Subject: Re: [PATCH 15/17] nvmet-tcp: enable TLS handshake upcall
On 8/14/23 14:48, Sagi Grimberg wrote:
>
>
> On 8/14/23 14:19, Hannes Reinecke wrote:
>> Add functions to start the TLS handshake upcall when
>> the TCP TSAS sectype is set to 'tls1.3' and add a config
>> option NVME_TARGET_TCP_TLS.
>
> Need to document the refcount added.
> Also the general design with upcalling tls handshake in
> userspace and continue from there...
>
Okay.
>>
>> Signed-off-by: Hannes Reinecke <hare@...e.de>
>> ---
>> drivers/nvme/target/Kconfig | 15 ++++
>> drivers/nvme/target/configfs.c | 21 +++++
>> drivers/nvme/target/nvmet.h | 1 +
>> drivers/nvme/target/tcp.c | 146 ++++++++++++++++++++++++++++++++-
>> 4 files changed, 179 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/nvme/target/Kconfig b/drivers/nvme/target/Kconfig
>> index 79fc64035ee3..8a6c9cae804c 100644
>> --- a/drivers/nvme/target/Kconfig
>> +++ b/drivers/nvme/target/Kconfig
>> @@ -84,6 +84,21 @@ config NVME_TARGET_TCP
>> If unsure, say N.
>> +config NVME_TARGET_TCP_TLS
>> + bool "NVMe over Fabrics TCP target TLS encryption support"
>> + depends on NVME_TARGET_TCP
>> + select NVME_COMMON
>> + select NVME_KEYRING
>> + select NET_HANDSHAKE
>> + select KEYS
>> + help
>> + Enables TLS encryption for the NVMe TCP target using the
>> netlink handshake API.
>> +
>> + The TLS handshake daemon is availble at
>> + https://github.com/oracle/ktls-utils.
>> +
>> + If unsure, say N.
>> +
>> config NVME_TARGET_AUTH
>> bool "NVMe over Fabrics In-band Authentication support"
>> depends on NVME_TARGET
>> diff --git a/drivers/nvme/target/configfs.c
>> b/drivers/nvme/target/configfs.c
>> index efbfed310370..ad1fb32c7387 100644
>> --- a/drivers/nvme/target/configfs.c
>> +++ b/drivers/nvme/target/configfs.c
>> @@ -15,6 +15,7 @@
>> #ifdef CONFIG_NVME_TARGET_AUTH
>> #include <linux/nvme-auth.h>
>> #endif
>> +#include <linux/nvme-keyring.h>
>> #include <crypto/hash.h>
>> #include <crypto/kpp.h>
>> @@ -397,6 +398,17 @@ static ssize_t nvmet_addr_tsas_store(struct
>> config_item *item,
>> return -EINVAL;
>> found:
>> + if (sectype == NVMF_TCP_SECTYPE_TLS13) {
>> + if (!IS_ENABLED(CONFIG_NVME_TARGET_TCP_TLS)) {
>> + pr_err("TLS is not supported\n");
>> + return -EINVAL;
>> + }
>> + if (!port->keyring) {
>> + pr_err("TLS keyring not configured\n");
>> + return -EINVAL;
>> + }
>> + }
>> +
>> nvmet_port_init_tsas_tcp(port, sectype);
>> /*
>> * The TLS implementation currently does not support
>> @@ -1815,6 +1827,7 @@ static void nvmet_port_release(struct
>> config_item *item)
>> flush_workqueue(nvmet_wq);
>> list_del(&port->global_entry);
>> + key_put(port->keyring);
>> kfree(port->ana_state);
>> kfree(port);
>> }
>> @@ -1864,6 +1877,14 @@ static struct config_group
>> *nvmet_ports_make(struct config_group *group,
>> return ERR_PTR(-ENOMEM);
>> }
>> + if (nvme_keyring_id()) {
>> + port->keyring = key_lookup(nvme_keyring_id());
>> + if (IS_ERR(port->keyring)) {
>> + pr_warn("NVMe keyring not available, disabling TLS\n");
>> + port->keyring = NULL;
>
> why setting this to NULL?
>
It's check when changing TSAS; we can only enable TLS if the nvme
keyring is available.
>> + }
>> + }
>> +
>> for (i = 1; i <= NVMET_MAX_ANAGRPS; i++) {
>> if (i == NVMET_DEFAULT_ANA_GRPID)
>> port->ana_state[1] = NVME_ANA_OPTIMIZED;
>> diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
>> index 8cfd60f3b564..7f9ae53c1df5 100644
>> --- a/drivers/nvme/target/nvmet.h
>> +++ b/drivers/nvme/target/nvmet.h
>> @@ -158,6 +158,7 @@ struct nvmet_port {
>> struct config_group ana_groups_group;
>> struct nvmet_ana_group ana_default_group;
>> enum nvme_ana_state *ana_state;
>> + struct key *keyring;
>> void *priv;
>> bool enabled;
>> int inline_data_size;
>> diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
>> index f19ea9d923fd..77fa339008e1 100644
>> --- a/drivers/nvme/target/tcp.c
>> +++ b/drivers/nvme/target/tcp.c
>> @@ -8,9 +8,13 @@
>> #include <linux/init.h>
>> #include <linux/slab.h>
>> #include <linux/err.h>
>> +#include <linux/key.h>
>> #include <linux/nvme-tcp.h>
>> +#include <linux/nvme-keyring.h>
>> #include <net/sock.h>
>> #include <net/tcp.h>
>> +#include <net/tls.h>
>> +#include <net/handshake.h>
>> #include <linux/inet.h>
>> #include <linux/llist.h>
>> #include <crypto/hash.h>
>> @@ -66,6 +70,16 @@ device_param_cb(idle_poll_period_usecs,
>> &set_param_ops,
>> MODULE_PARM_DESC(idle_poll_period_usecs,
>> "nvmet tcp io_work poll till idle time period in usecs:
>> Default 0");
>> +#ifdef CONFIG_NVME_TARGET_TCP_TLS
>> +/*
>> + * TLS handshake timeout
>> + */
>> +static int tls_handshake_timeout = 10;
>> +module_param(tls_handshake_timeout, int, 0644);
>> +MODULE_PARM_DESC(tls_handshake_timeout,
>> + "nvme TLS handshake timeout in seconds (default 10)");
>> +#endif
>> +
>> #define NVMET_TCP_RECV_BUDGET 8
>> #define NVMET_TCP_SEND_BUDGET 8
>> #define NVMET_TCP_IO_WORK_BUDGET 64
>> @@ -122,11 +136,13 @@ struct nvmet_tcp_cmd {
>> enum nvmet_tcp_queue_state {
>> NVMET_TCP_Q_CONNECTING,
>> + NVMET_TCP_Q_TLS_HANDSHAKE,
>> NVMET_TCP_Q_LIVE,
>> NVMET_TCP_Q_DISCONNECTING,
>> };
>> struct nvmet_tcp_queue {
>> + struct kref kref;
>
> Why is kref the first member of the struct?
>
Habit.
I don't mind where it'll end up.
>> struct socket *sock;
>> struct nvmet_tcp_port *port;
>> struct work_struct io_work;
>> @@ -155,6 +171,10 @@ struct nvmet_tcp_queue {
>> struct ahash_request *snd_hash;
>> struct ahash_request *rcv_hash;
>> + /* TLS state */
>> + key_serial_t tls_pskid;
>> + struct delayed_work tls_handshake_work;
>> +
>> unsigned long poll_end;
>> spinlock_t state_lock;
>> @@ -1283,12 +1303,21 @@ static int nvmet_tcp_try_recv(struct
>> nvmet_tcp_queue *queue,
>> return ret;
>> }
>> +static void nvmet_tcp_release_queue(struct kref *kref)
>> +{
>> + struct nvmet_tcp_queue *queue =
>> + container_of(kref, struct nvmet_tcp_queue, kref);
>> +
>> + WARN_ON(queue->state != NVMET_TCP_Q_DISCONNECTING);
>> + queue_work(nvmet_wq, &queue->release_work);
>> +}
>> +
>> static void nvmet_tcp_schedule_release_queue(struct nvmet_tcp_queue
>> *queue)
>> {
>> spin_lock_bh(&queue->state_lock);
>> if (queue->state != NVMET_TCP_Q_DISCONNECTING) {
>> queue->state = NVMET_TCP_Q_DISCONNECTING;
>> - queue_work(nvmet_wq, &queue->release_work);
>> + kref_put(&queue->kref, nvmet_tcp_release_queue);
>> }
>> spin_unlock_bh(&queue->state_lock);
>> }
>> @@ -1485,6 +1514,8 @@ static void nvmet_tcp_release_queue_work(struct
>> work_struct *w)
>> mutex_unlock(&nvmet_tcp_queue_mutex);
>> nvmet_tcp_restore_socket_callbacks(queue);
>> + tls_handshake_cancel(queue->sock->sk);
>> + cancel_delayed_work_sync(&queue->tls_handshake_work);
>
> We should call it tls_handshake_tmo_work or something to make it
> clear it is a timeout work.
>
Okay.
>> cancel_work_sync(&queue->io_work);
>> /* stop accepting incoming data */
>> queue->rcv_state = NVMET_TCP_RECV_ERR;
>> @@ -1512,8 +1543,13 @@ static void nvmet_tcp_data_ready(struct sock *sk)
>> read_lock_bh(&sk->sk_callback_lock);
>> queue = sk->sk_user_data;
>> - if (likely(queue))
>> - queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
>> + if (likely(queue)) {
>> + if (queue->data_ready)
>> + queue->data_ready(sk);
>> + if (queue->state != NVMET_TCP_Q_TLS_HANDSHAKE)
>> + queue_work_on(queue_cpu(queue), nvmet_tcp_wq,
>> + &queue->io_work);
>> + }
>> read_unlock_bh(&sk->sk_callback_lock);
>> }
>> @@ -1621,6 +1657,83 @@ static int nvmet_tcp_set_queue_sock(struct
>> nvmet_tcp_queue *queue)
>> return ret;
>> }
>> +#ifdef CONFIG_NVME_TARGET_TCP_TLS
>> +static void nvmet_tcp_tls_handshake_done(void *data, int status,
>> + key_serial_t peerid)
>> +{
>> + struct nvmet_tcp_queue *queue = data;
>> +
>> + pr_debug("queue %d: TLS handshake done, key %x, status %d\n",
>> + queue->idx, peerid, status);
>> + spin_lock_bh(&queue->state_lock);
>> + if (queue->state != NVMET_TCP_Q_TLS_HANDSHAKE) {
>
> Is this even possible?
>
I guess it can happen when the socket closes during handshake; the
daemon might still be sending a 'done' event but
nvmet_tcp_schedule_release_queue() has been called.
>> + pr_warn("queue %d: TLS handshake already completed\n",
>> + queue->idx);
>> + spin_unlock_bh(&queue->state_lock);
>> + kref_put(&queue->kref, nvmet_tcp_release_queue);
>
> How can we get here?
>
See above.
>> + return;
>> + }
>> + if (!status)
>> + queue->tls_pskid = peerid;
>> + queue->state = NVMET_TCP_Q_CONNECTING;
>> + spin_unlock_bh(&queue->state_lock);
>> +
>> + cancel_delayed_work_sync(&queue->tls_handshake_work);
>> + if (status) {
>
> Wait, did we assign the sk_state_change in this stage? What will
> sock shutdown trigger?
>
That, however is a good point. You might be right.
Will be checking.
>> + kernel_sock_shutdown(queue->sock, SHUT_RDWR);
>
> Probably the put can be moved to a out: label in the end.
>
Probably.
>> + kref_put(&queue->kref, nvmet_tcp_release_queue);
>> + return;
>> + }
>> +
>> + pr_debug("queue %d: resetting queue callbacks after TLS
>> handshake\n",
>> + queue->idx);
>> + nvmet_tcp_set_queue_sock(queue);
>> + kref_put(&queue->kref, nvmet_tcp_release_queue);
>> +}
>> +
>> +static void nvmet_tcp_tls_handshake_timeout_work(struct work_struct *w)
>> +{
>> + struct nvmet_tcp_queue *queue = container_of(to_delayed_work(w),
>> + struct nvmet_tcp_queue, tls_handshake_work);
>> +
>> + pr_debug("queue %d: TLS handshake timeout\n", queue->idx);
>
> Probably its better to make this pr_warn...
>
Ok.
>> + if (!tls_handshake_cancel(queue->sock->sk))
>> + return;
>> + kernel_sock_shutdown(queue->sock, SHUT_RDWR);
>
> Same question here, did we assign sk_state_change yet?
>
Will be checking.
>> + kref_put(&queue->kref, nvmet_tcp_release_queue);
>> +}
>> +
>> +static int nvmet_tcp_tls_handshake(struct nvmet_tcp_queue *queue)
>> +{
>> + int ret = -EOPNOTSUPP;
>> + struct tls_handshake_args args;
>> +
>> + if (queue->state != NVMET_TCP_Q_TLS_HANDSHAKE) {
>> + pr_warn("cannot start TLS in state %d\n", queue->state);
>> + return -EINVAL;
>> + }
>> +
>> + kref_get(&queue->kref);
>> + pr_debug("queue %d: TLS ServerHello\n", queue->idx);
>> + memset(&args, 0, sizeof(args));
>> + args.ta_sock = queue->sock;
>> + args.ta_done = nvmet_tcp_tls_handshake_done;
>> + args.ta_data = queue;
>> + args.ta_keyring = key_serial(queue->port->nport->keyring);
>> + args.ta_timeout_ms = tls_handshake_timeout * 1000;
>> +
>> + ret = tls_server_hello_psk(&args, GFP_KERNEL);
>> + if (ret) {
>> + kref_put(&queue->kref, nvmet_tcp_release_queue);
>> + pr_err("failed to start TLS, err=%d\n", ret);
>> + } else {
>> + queue_delayed_work(nvmet_wq, &queue->tls_handshake_work,
>> + tls_handshake_timeout * HZ);
>> + }
>> + return ret;
>> +}
>> +#endif
>> +
>> static void nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
>> struct socket *newsock)
>> {
>> @@ -1636,11 +1749,16 @@ static void nvmet_tcp_alloc_queue(struct
>> nvmet_tcp_port *port,
>> INIT_WORK(&queue->release_work, nvmet_tcp_release_queue_work);
>> INIT_WORK(&queue->io_work, nvmet_tcp_io_work);
>> + kref_init(&queue->kref);
>> queue->sock = newsock;
>> queue->port = port;
>> queue->nr_cmds = 0;
>> spin_lock_init(&queue->state_lock);
>> - queue->state = NVMET_TCP_Q_CONNECTING;
>> + if (queue->port->nport->disc_addr.tsas.tcp.sectype ==
>> + NVMF_TCP_SECTYPE_TLS13)
>> + queue->state = NVMET_TCP_Q_TLS_HANDSHAKE;
>> + else
>> + queue->state = NVMET_TCP_Q_CONNECTING;
>> INIT_LIST_HEAD(&queue->free_list);
>> init_llist_head(&queue->resp_list);
>> INIT_LIST_HEAD(&queue->resp_send_list);
>> @@ -1671,12 +1789,32 @@ static void nvmet_tcp_alloc_queue(struct
>> nvmet_tcp_port *port,
>> list_add_tail(&queue->queue_list, &nvmet_tcp_queue_list);
>> mutex_unlock(&nvmet_tcp_queue_mutex);
>> +#ifdef CONFIG_NVME_TARGET_TCP_TLS
>> + INIT_DELAYED_WORK(&queue->tls_handshake_work,
>> + nvmet_tcp_tls_handshake_timeout_work);
>> + if (queue->state == NVMET_TCP_Q_TLS_HANDSHAKE) {
>> + struct sock *sk = queue->sock->sk;
>> +
>> + /* Restore the default callbacks before starting upcall */
>> + read_lock_bh(&sk->sk_callback_lock);
>> + sk->sk_user_data = NULL;
>> + sk->sk_data_ready = port->data_ready;
>> + read_unlock_bh(&sk->sk_callback_lock);
>> + if (!nvmet_tcp_tls_handshake(queue))
>> + return;
>> +
>> + /* TLS handshake failed, terminate the connection */
>> + goto out_destroy_sq;
>> + }
>> +#endif
>> +
>> ret = nvmet_tcp_set_queue_sock(queue);
>> if (ret)
>> goto out_destroy_sq;
>> return;
>> out_destroy_sq:
>> + queue->state = NVMET_TCP_Q_DISCONNECTING;
>
> Can you clarify what this is used for?
>
Primarily for debugging, to signal that we really are
disconnecting. But yeah, not really required.
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@...e.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Frankenstr. 146, 90461 Nürnberg
Managing Directors: I. Totev, A. Myers, A. McDonald, M. B. Moerman
(HRB 36809, AG Nürnberg)
Powered by blists - more mailing lists