Commit Graph

21 Commits

Author SHA1 Message Date
Tariq Toukan
52d3c2e629 net/tls: Fix race in TLS device down flow
[ Upstream commit f08d8c1bb97c48f24a82afaa2fd8c140f8d3da8b ]

Socket destruction flow and tls_device_down function sync against each
other using tls_device_lock and the context refcount, to guarantee the
device resources are freed via tls_dev_del() by the end of
tls_device_down.

In the following unfortunate flow, this won't happen:
- refcount is decreased to zero in tls_device_sk_destruct.
- tls_device_down starts, skips the context as refcount is zero, going
  all the way until it flushes the gc work, and returns without freeing
  the device resources.
- only then, tls_device_queue_ctx_destruction is called, queues the gc
  work and frees the context's device resources.

Solve it by decreasing the refcount in the socket's destruction flow
under the tls_device_lock, for perfect synchronization.  This does not
slow down the common likely destructor flow, in which both the refcount
is decreased and the spinlock is acquired, anyway.

Fixes: e8f6979981 ("net/tls: Add generic NIC offload infrastructure")
Reviewed-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-29 17:10:32 +02:00
Maxim Mikityanskiy
2ba413da62 net/tls: Protect from calling tls_dev_del for TLS RX twice
[ Upstream commit 025cc2fb6a4e84e9a0552c0017dcd1c24b7ac7da ]

tls_device_offload_cleanup_rx doesn't clear tls_ctx->netdev after
calling tls_dev_del if TLX TX offload is also enabled. Clearing
tls_ctx->netdev gets postponed until tls_device_gc_task. It leaves a
time frame when tls_device_down may get called and call tls_dev_del for
RX one extra time, confusing the driver, which may lead to a crash.

This patch corrects this racy behavior by adding a flag to prevent
tls_device_down from calling tls_dev_del the second time.

Fixes: e8f6979981 ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Link: https://lore.kernel.org/r/20201125221810.69870-1-saeedm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-08 10:18:52 +01:00
Rohit Maheshwari
b2d31640d4 net/tls: sendfile fails with ktls offload
[ Upstream commit ea1dd3e9d080c961b9a451130b61c72dc9a5397b ]

At first when sendpage gets called, if there is more data, 'more' in
tls_push_data() gets set which later sets pending_open_record_frags, but
when there is no more data in file left, and last time tls_push_data()
gets called, pending_open_record_frags doesn't get reset. And later when
2 bytes of encrypted alert comes as sendmsg, it first checks for
pending_open_record_frags, and since this is set, it creates a record with
0 data bytes to encrypt, meaning record length is prepend_size + tag_size
only, which causes problem.
 We should set/reset pending_open_record_frags based on more bit.

Fixes: e8f6979981 ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-29 09:54:56 +01:00
Ira Weiny
bc8ce7de36 net/tls: Fix kmap usage
[ Upstream commit b06c19d9f827f6743122795570bfc0c72db482b0 ]

When MSG_OOB is specified to tls_device_sendpage() the mapped page is
never unmapped.

Hold off mapping the page until after the flags are checked and the page
is actually needed.

Fixes: e8f6979981 ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-19 08:15:03 +02:00
Rohit Maheshwari
29a84e8c4e net/tls: Fix to avoid gettig invalid tls record
[ Upstream commit 06f5201c6392f998a49ca9c9173e2930c8eb51d8 ]

Current code doesn't check if tcp sequence number is starting from (/after)
1st record's start sequnce number. It only checks if seq number is before
1st record's end sequnce number. This problem will always be a possibility
in re-transmit case. If a record which belongs to a requested seq number is
already deleted, tls_get_record will start looking into list and as per the
check it will look if seq number is before the end seq of 1st record, which
will always be true and will return 1st record always, it should in fact
return NULL.
As part of the fix, start looking each record only if the sequence number
lies in the list else return NULL.
There is one more check added, driver look for the start marker record to
handle tcp packets which are before the tls offload start sequence number,
hence return 1st record if the record is tls start marker and seq number is
before the 1st record's starting sequence number.

Fixes: e8f6979981 ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-05 16:42:17 +01:00
Jakub Kicinski
fde351aeff net/tls: make sure offload also gets the keys wiped
[ Upstream commit acd3e96d53a24d219f720ed4012b62723ae05da1 ]

Commit 86029d10af ("tls: zero the crypto information from tls_context
before freeing") added memzero_explicit() calls to clear the key material
before freeing struct tls_context, but it missed tls_device.c has its
own way of freeing this structure. Replace the missing free.

Fixes: 86029d10af ("tls: zero the crypto information from tls_context before freeing")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-28 08:29:27 +02:00
Jakub Kicinski
be0343af12 net/tls: replace the sleeping lock around RX resync with a bit lock
[ Upstream commit e52972c11d6b1262964db96d65934196db621685 ]

Commit 38030d7cb779 ("net/tls: avoid NULL-deref on resync during device removal")
tried to fix a potential NULL-dereference by taking the
context rwsem.  Unfortunately the RX resync may get called
from soft IRQ, so we can't use the rwsem to protect from
the device disappearing.  Because we are guaranteed there
can be only one resync at a time (it's called from strparser)
use a bit to indicate resync is busy and make device
removal wait for the bit to get cleared.

Note that there is a leftover "flags" field in struct
tls_context already.

Fixes: 4799ac81e5 ("tls: Add rx inline crypto offload")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-11 12:20:49 +02:00
Jakub Kicinski
fb6cf4f370 net/tls: don't ignore netdev notifications if no TLS features
[ Upstream commit c3f4a6c39cf269a40d45f813c05fa830318ad875 ]

On device surprise removal path (the notifier) we can't
bail just because the features are disabled.  They may
have been enabled during the lifetime of the device.
This bug leads to leaking netdev references and
use-after-frees if there are active connections while
device features are cleared.

Fixes: e8f6979981 ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-04 08:02:33 +02:00
Jakub Kicinski
fb69403ec2 net/tls: fix state removal with feature flags off
[ Upstream commit 3686637e507b48525fcea6fb91e1988bdbc14530 ]

TLS offload drivers shouldn't (and currently don't) block
the TLS offload feature changes based on whether there are
active offloaded connections or not.

This seems to be a good idea, because we want the admin to
be able to disable the TLS offload at any time, and there
is no clean way of disabling it for active connections
(TX side is quite problematic).  So if features are cleared
existing connections will stay offloaded until they close,
and new connections will not attempt offload to a given
device.

However, the offload state removal handling is currently
broken if feature flags get cleared while there are
active TLS offloads.

RX side will completely bail from cleanup, even on normal
remove path, leaving device state dangling, potentially
causing issues when the 5-tuple is reused.  It will also
fail to release the netdev reference.

Remove the RX-side warning message, in next release cycle
it should be printed when features are disabled, rather
than when connection dies, but for that we need a more
efficient method of finding connection of a given netdev
(a'la BPF offload code).

Fixes: 4799ac81e5 ("tls: Add rx inline crypto offload")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-04 08:02:33 +02:00
Jakub Kicinski
85b9e8694f net/tls: fix the IV leaks
[ Upstream commit 5a03bc73abed6ae196c15e9950afde19d48be12c ]

Commit f66de3ee2c ("net/tls: Split conf to rx + tx") made
freeing of IV and record sequence number conditional to SW
path only, but commit e8f6979981 ("net/tls: Add generic NIC
offload infrastructure") also allocates that state for the
device offload configuration.  Remember to free it.

Fixes: e8f6979981 ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
2019-05-16 19:41:27 +02:00
Jakub Kicinski
d0771bd41c net/tls: fix copy to fragments in reencrypt
[ Upstream commit eb3d38d5adb520435d4e4af32529ccb13ccc9935 ]

Fragments may contain data from other records so we have to account
for that when we calculate the destination and max length of copy we
can perform.  Note that 'offset' is the offset within the message,
so it can't be passed as offset within the frag..

Here skb_store_bits() would have realised the call is wrong and
simply not copy data.

Fixes: 4799ac81e5 ("tls: Add rx inline crypto offload")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-05 14:42:40 +02:00
Jakub Kicinski
dd424182bc net/tls: don't copy negative amounts of data in reencrypt
[ Upstream commit 97e1caa517e22d62a283b876fb8aa5f4672c83dd ]

There is no guarantee the record starts before the skb frags.
If we don't check for this condition copy amount will get
negative, leading to reads and writes to random memory locations.
Familiar hilarity ensues.

Fixes: 4799ac81e5 ("tls: Add rx inline crypto offload")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-05 14:42:40 +02:00
Jakub Kicinski
53db652324 net/tls: don't leak IV and record seq when offload fails
[ Upstream commit 12c7686111326148b4b5db189130522a4ad1be4a ]

When device refuses the offload in tls_set_device_offload_rx()
it calls tls_sw_free_resources_rx() to clean up software context
state.

Unfortunately, tls_sw_free_resources_rx() does not free all
the state tls_set_sw_offload() allocated - it leaks IV and
sequence number buffers.  All other code paths which lead to
tls_sw_release_resources_rx() (which tls_sw_free_resources_rx()
calls) free those right before the call.

Avoid the leak by moving freeing of iv and rec_seq into
tls_sw_release_resources_rx().

Fixes: 4799ac81e5 ("tls: Add rx inline crypto offload")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-02 09:59:01 +02:00
Jakub Kicinski
d3bdd359fa net/tls: avoid potential deadlock in tls_set_device_offload_rx()
[ Upstream commit 62ef81d5632634d5e310ed25b9b940b2b6612b46 ]

If device supports offload, but offload fails tls_set_device_offload_rx()
will call tls_sw_free_resources_rx() which (unhelpfully) releases
and reacquires the socket lock.

For a small fix release and reacquire the device_offload_lock.

Fixes: 4799ac81e5 ("tls: Add rx inline crypto offload")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-02 09:59:01 +02:00
Sabrina Dubroca
86029d10af tls: zero the crypto information from tls_context before freeing
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: 3c4d755915 ("tls: kernel TLS support")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-13 12:03:47 -07:00
zhong jiang
969d509003 net/tls: Use kmemdup to simplify the code
Kmemdup is better than kmalloc+memcpy. So replace them.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-01 09:47:47 -07:00
Gustavo A. R. Silva
eecd685770 tls: Fix copy-paste error in tls_device_reencrypt
It seems that the proper structure to use in this particular
case is *skb_iter* instead of skb.

Addresses-Coverity-ID: 1471906 ("Copy-paste error")
Fixes: 4799ac81e5 ("tls: Add rx inline crypto offload")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-20 12:12:45 -07:00
Boris Pismenny
4799ac81e5 tls: Add rx inline crypto offload
This patch completes the generic infrastructure to offload TLS crypto to a
network device. It enables the kernel to skip decryption and
authentication of some skbs marked as decrypted by the NIC. In the fast
path, all packets received are decrypted by the NIC and the performance
is comparable to plain TCP.

This infrastructure doesn't require a TCP offload engine. Instead, the
NIC only decrypts packets that contain the expected TCP sequence number.
Out-Of-Order TCP packets are provided unmodified. As a result, at the
worst case a received TLS record consists of both plaintext and ciphertext
packets. These partially decrypted records must be reencrypted,
only to be decrypted.

The notable differences between SW KTLS Rx and this offload are as
follows:
1. Partial decryption - Software must handle the case of a TLS record
that was only partially decrypted by HW. This can happen due to packet
reordering.
2. Resynchronization - tls_read_size calls the device driver to
resynchronize HW after HW lost track of TLS record framing in
the TCP stream.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-16 00:13:11 -07:00
Boris Pismenny
d80a1b9d18 tls: Refactor tls_offload variable names
For symmetry, we rename tls_offload_context to
tls_offload_context_tx before we add tls_offload_context_rx.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-16 00:12:09 -07:00
Boris Pismenny
895262d857 tls: Fix tls_device initialization
Add sg table initialization to fix a BUG_ON encountered when enabling
CONFIG_DEBUG_SG.

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-10 17:54:20 -04:00
Ilya Lesokhin
e8f6979981 net/tls: Add generic NIC offload infrastructure
This patch adds a generic infrastructure to offload TLS crypto to a
network device. It enables the kernel TLS socket to skip encryption
and authentication operations on the transmit side of the data path.
Leaving those computationally expensive operations to the NIC.

The NIC offload infrastructure builds TLS records and pushes them to
the TCP layer just like the SW KTLS implementation and using the same
API.
TCP segmentation is mostly unaffected. Currently the only exception is
that we prevent mixed SKBs where only part of the payload requires
offload. In the future we are likely to add a similar restriction
following a change cipher spec record.

The notable differences between SW KTLS and NIC offloaded TLS
implementations are as follows:
1. The offloaded implementation builds "plaintext TLS record", those
records contain plaintext instead of ciphertext and place holder bytes
instead of authentication tags.
2. The offloaded implementation maintains a mapping from TCP sequence
number to TLS records. Thus given a TCP SKB sent from a NIC offloaded
TLS socket, we can use the tls NIC offload infrastructure to obtain
enough context to encrypt the payload of the SKB.
A TLS record is released when the last byte of the record is ack'ed,
this is done through the new icsk_clean_acked callback.

The infrastructure should be extendable to support various NIC offload
implementations.  However it is currently written with the
implementation below in mind:
The NIC assumes that packets from each offloaded stream are sent as
plaintext and in-order. It keeps track of the TLS records in the TCP
stream. When a packet marked for offload is transmitted, the NIC
encrypts the payload in-place and puts authentication tags in the
relevant place holders.

The responsibility for handling out-of-order packets (i.e. TCP
retransmission, qdisc drops) falls on the netdev driver.

The netdev driver keeps track of the expected TCP SN from the NIC's
perspective.  If the next packet to transmit matches the expected TCP
SN, the driver advances the expected TCP SN, and transmits the packet
with TLS offload indication.

If the next packet to transmit does not match the expected TCP SN. The
driver calls the TLS layer to obtain the TLS record that includes the
TCP of the packet for transmission. Using this TLS record, the driver
posts a work entry on the transmit queue to reconstruct the NIC TLS
state required for the offload of the out-of-order packet. It updates
the expected TCP SN accordingly and transmits the now in-order packet.
The same queue is used for packet transmission and TLS context
reconstruction to avoid the need for flushing the transmit queue before
issuing the context reconstruction request.

Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Aviad Yehezkel <aviadye@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-01 09:42:47 -04:00