KTLS uses a stream parser to collect TLS messages and send them to
the upper layer tls receive handler. This ensures the tls receiver
has a full TLS header to parse when it is run. However, when a
socket has BPF_SK_SKB_STREAM_VERDICT program attached before KTLS
is enabled we end up with two stream parsers running on the same
socket.
The result is both try to run on the same socket. First the KTLS
stream parser runs and calls read_sock() which will tcp_read_sock
which in turn calls tcp_rcv_skb(). This dequeues the skb from the
sk_receive_queue. When this is done KTLS code then data_ready()
callback which because we stacked KTLS on top of the bpf stream
verdict program has been replaced with sk_psock_start_strp(). This
will in turn kick the stream parser again and eventually do the
same thing KTLS did above calling into tcp_rcv_skb() and dequeuing
a skb from the sk_receive_queue.
At this point the data stream is broke. Part of the stream was
handled by the KTLS side some other bytes may have been handled
by the BPF side. Generally this results in either missing data
or more likely a "Bad Message" complaint from the kTLS receive
handler as the BPF program steals some bytes meant to be in a
TLS header and/or the TLS header length is no longer correct.
We've already broke the idealized model where we can stack ULPs
in any order with generic callbacks on the TX side to handle this.
So in this patch we do the same thing but for RX side. We add
a sk_psock_strp_enabled() helper so TLS can learn a BPF verdict
program is running and add a tls_sw_has_ctx_rx() helper so BPF
side can learn there is a TLS ULP on the socket.
Then on BPF side we omit calling our stream parser to avoid
breaking the data stream for the KTLS receiver. Then on the
KTLS side we call BPF_SK_SKB_STREAM_VERDICT once the KTLS
receiver is done with the packet but before it posts the
msg to userspace. This gives us symmetry between the TX and
RX halfs and IMO makes it usable again. On the TX side we
process packets in this order BPF -> TLS -> TCP and on
the receive side in the reverse order TCP -> TLS -> BPF.
Discovered while testing OpenSSL 3.0 Alpha2.0 release.
Fixes: d829e9c411 ("tls: convert to generic sk_msg interface")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/159079361946.5745.605854335665044485.stgit@john-Precision-5820-Tower
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
tls_sw_recvmsg() and tls_decrypt_done() can be run concurrently.
// tls_sw_recvmsg()
if (atomic_read(&ctx->decrypt_pending))
crypto_wait_req(-EINPROGRESS, &ctx->async_wait);
else
reinit_completion(&ctx->async_wait.completion);
//tls_decrypt_done()
pending = atomic_dec_return(&ctx->decrypt_pending);
if (!pending && READ_ONCE(ctx->async_notify))
complete(&ctx->async_wait.completion);
Consider the scenario tls_decrypt_done() is about to run complete()
if (!pending && READ_ONCE(ctx->async_notify))
and tls_sw_recvmsg() reads decrypt_pending == 0, does reinit_completion(),
then tls_decrypt_done() runs complete(). This sequence of execution
results in wrong completion. Consequently, for next decrypt request,
it will not wait for completion, eventually on connection close, crypto
resources freed, there is no way to handle pending decrypt response.
This race condition can be avoided by having atomic_read() mutually
exclusive with atomic_dec_return(),complete().Intoduced spin lock to
ensure the mutual exclution.
Addressed similar problem in tx direction.
v1->v2:
- More readable commit message.
- Corrected the lock to fix new race scenario.
- Removed barrier which is not needed now.
Fixes: a42055e8d2 ("net/tls: Add support for async encryption of records for performance")
Signed-off-by: Vinay Kumar Yadav <vinay.yadav@chelsio.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We cannot free record on any transient error because it leads to
losing previos data. Check socket error to know whether record must
be freed or not.
Fixes: d10523d0b3 ("net/tls: free the record on encryption error")
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
bpf_exec_tx_verdict() can return negative value for copied
variable. In that case this value will be pushed back to caller
and the real error code will be lost. Fix it using signed type and
checking for positive value.
Fixes: d10523d0b3 ("net/tls: free the record on encryption error")
Fixes: d3b18ad31f ("tls: add bpf support to sk_msg handling")
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
tls_data_ready() invokes sk_psock_get(), which returns a reference of
the specified sk_psock object to "psock" with increased refcnt.
When tls_data_ready() returns, local variable "psock" becomes invalid,
so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of
tls_data_ready(). When "psock->ingress_msg" is empty but "psock" is not
NULL, the function forgets to decrease the refcnt increased by
sk_psock_get(), causing a refcnt leak.
Fix this issue by calling sk_psock_put() on all paths when "psock" is
not NULL.
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bpf_exec_tx_verdict() invokes sk_psock_get(), which returns a reference
of the specified sk_psock object to "psock" with increased refcnt.
When bpf_exec_tx_verdict() returns, local variable "psock" becomes
invalid, so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of
bpf_exec_tx_verdict(). When "policy" equals to NULL but "psock" is not
NULL, the function forgets to decrease the refcnt increased by
sk_psock_get(), causing a refcnt leak.
Fix this issue by calling sk_psock_put() on this error path before
bpf_exec_tx_verdict() returns.
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann says:
====================
pull-request: bpf 2020-01-15
The following pull-request contains BPF updates for your *net* tree.
We've added 12 non-merge commits during the last 9 day(s) which contain
a total of 13 files changed, 95 insertions(+), 43 deletions(-).
The main changes are:
1) Fix refcount leak for TCP time wait and request sockets for socket lookup
related BPF helpers, from Lorenz Bauer.
2) Fix wrong verification of ARSH instruction under ALU32, from Daniel Borkmann.
3) Batch of several sockmap and related TLS fixes found while operating
more complex BPF programs with Cilium and OpenSSL, from John Fastabend.
4) Fix sockmap to read psock's ingress_msg queue before regular sk_receive_queue()
to avoid purging data upon teardown, from Lingpeng Chen.
5) Fix printing incorrect pointer in bpftool's btf_dump_ptr() in order to properly
dump a BPF map's value with BTF, from Martin KaFai Lau.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
When user returns SK_DROP we need to reset the number of copied bytes
to indicate to the user the bytes were dropped and not sent. If we
don't reset the copied arg sendmsg will return as if those bytes were
copied giving the user a positive return value.
This works as expected today except in the case where the user also
pops bytes. In the pop case the sg.size is reduced but we don't correctly
account for this when copied bytes is reset. The popped bytes are not
accounted for and we return a small positive value potentially confusing
the user.
The reason this happens is due to a typo where we do the wrong comparison
when accounting for pop bytes. In this fix notice the if/else is not
needed and that we have a similar problem if we push data except its not
visible to the user because if delta is larger the sg.size we return a
negative value so it appears as an error regardless.
Fixes: 7246d8ed4d ("bpf: helper to pop data from messages")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20200111061206.8028-9-john.fastabend@gmail.com
Its possible through a set of push, pop, apply helper calls to construct
a skmsg, which is just a ring of scatterlist elements, with the start
value larger than the end value. For example,
end start
|_0_|_1_| ... |_n_|_n+1_|
Where end points at 1 and start points and n so that valid elements is
the set {n, n+1, 0, 1}.
Currently, because we don't build the correct chain only {n, n+1} will
be sent. This adds a check and sg_chain call to correctly submit the
above to the crypto and tls send path.
Fixes: d3b18ad31f ("tls: add bpf support to sk_msg handling")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20200111061206.8028-8-john.fastabend@gmail.com
It is possible to build a plaintext buffer using push helper that is larger
than the allocated encrypt buffer. When this record is pushed to crypto
layers this can result in a NULL pointer dereference because the crypto
API expects the encrypt buffer is large enough to fit the plaintext
buffer. Kernel splat below.
To resolve catch the cases this can happen and split the buffer into two
records to send individually. Unfortunately, there is still one case to
handle where the split creates a zero sized buffer. In this case we merge
the buffers and unmark the split. This happens when apply is zero and user
pushed data beyond encrypt buffer. This fixes the original case as well
because the split allocated an encrypt buffer larger than the plaintext
buffer and the merge simply moves the pointers around so we now have
a reference to the new (larger) encrypt buffer.
Perhaps its not ideal but it seems the best solution for a fixes branch
and avoids handling these two cases, (a) apply that needs split and (b)
non apply case. The are edge cases anyways so optimizing them seems not
necessary unless someone wants later in next branches.
[ 306.719107] BUG: kernel NULL pointer dereference, address: 0000000000000008
[...]
[ 306.747260] RIP: 0010:scatterwalk_copychunks+0x12f/0x1b0
[...]
[ 306.770350] Call Trace:
[ 306.770956] scatterwalk_map_and_copy+0x6c/0x80
[ 306.772026] gcm_enc_copy_hash+0x4b/0x50
[ 306.772925] gcm_hash_crypt_remain_continue+0xef/0x110
[ 306.774138] gcm_hash_crypt_continue+0xa1/0xb0
[ 306.775103] ? gcm_hash_crypt_continue+0xa1/0xb0
[ 306.776103] gcm_hash_assoc_remain_continue+0x94/0xa0
[ 306.777170] gcm_hash_assoc_continue+0x9d/0xb0
[ 306.778239] gcm_hash_init_continue+0x8f/0xa0
[ 306.779121] gcm_hash+0x73/0x80
[ 306.779762] gcm_encrypt_continue+0x6d/0x80
[ 306.780582] crypto_gcm_encrypt+0xcb/0xe0
[ 306.781474] crypto_aead_encrypt+0x1f/0x30
[ 306.782353] tls_push_record+0x3b9/0xb20 [tls]
[ 306.783314] ? sk_psock_msg_verdict+0x199/0x300
[ 306.784287] bpf_exec_tx_verdict+0x3f2/0x680 [tls]
[ 306.785357] tls_sw_sendmsg+0x4a3/0x6a0 [tls]
test_sockmap test signature to trigger bug,
[TEST]: (1, 1, 1, sendmsg, pass,redir,start 1,end 2,pop (1,2),ktls,):
Fixes: d3b18ad31f ("tls: add bpf support to sk_msg handling")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20200111061206.8028-7-john.fastabend@gmail.com
Mallesham reports the TLS with async accelerator was broken by
commit d10523d0b3 ("net/tls: free the record on encryption error")
because encryption can return -EINPROGRESS in such setups, which
should not be treated as an error.
The error is also present in the BPF path (likely copied from there).
Reported-by: Mallesham Jatharakonda <mallesham.jatharakonda@oneconvergence.com>
Fixes: d3b18ad31f ("tls: add bpf support to sk_msg handling")
Fixes: d10523d0b3 ("net/tls: free the record on encryption error")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When device loses sync mid way through a record - kernel
has to re-encrypt the part of the record which the device
already decrypted to be able to decrypt and authenticate
the record in its entirety.
The re-encryption piggy backs on the decryption routine,
but obviously because the partially decrypted record can't
be authenticated crypto API returns an error which is then
ignored by tls_device_reencrypt().
Commit 5c5ec66858 ("net/tls: add TlsDecryptError stat")
added a statistic to count decryption errors, this statistic
can't be incremented when we see the expected re-encryption
error. Move the inc to the caller.
Reported-and-tested-by: David Beckett <david.beckett@netronome.com>
Fixes: 5c5ec66858 ("net/tls: add TlsDecryptError stat")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ENOTSUPP is not available in userspace, for example:
setsockopt failed, 524, Unknown error 524
Signed-off-by: Valentin Vidic <vvidic@valentin-vidic.from.hr>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Partially sent record cleanup path increments an SG entry
directly instead of using sg_next(). This should not be a
problem today, as encrypted messages should be always
allocated as arrays. But given this is a cleanup path it's
easy to miss was this ever to change. Use sg_next(), and
simplify the code.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Looks like when BPF support was added by commit d3b18ad31f
("tls: add bpf support to sk_msg handling") and
commit d829e9c411 ("tls: convert to generic sk_msg interface")
it broke/removed the support for in-place crypto as added by
commit 4e6d47206c ("tls: Add support for inplace records
encryption").
The inplace_crypto member of struct tls_rec is dead, inited
to zero, and sometimes set to zero again. It used to be
set to 1 when record was allocated, but the skmsg code doesn't
seem to have been written with the idea of in-place crypto
in mind.
Since non trivial effort is required to bring the feature back
and we don't really have the HW to measure the benefit just
remove the left over support for now to avoid confusing readers.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When tls_do_encryption() fails the SG lists are left with the
SG_END and SG_CHAIN marks in place. One could hope that once
encryption fails we will never see the record again, but that
is in fact not true. Commit d3b18ad31f ("tls: add bpf support
to sk_msg handling") added special handling to ENOMEM and ENOSPC
errors which mean we may see the same record re-submitted.
As suggested by John free the record, the BPF code is already
doing just that.
Reported-by: syzbot+df0d4ec12332661dd1f9@syzkaller.appspotmail.com
Fixes: d3b18ad31f ("tls: add bpf support to sk_msg handling")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
bpf_exec_tx_verdict() may free the record if tls_push_record()
fails, or if the entire record got consumed by BPF. Re-check
ctx->open_rec before touching the data.
Fixes: d3b18ad31f ("tls: add bpf support to sk_msg handling")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Minor conflict in drivers/s390/net/qeth_l2_main.c, kept the lock
from commit c8183f5489 ("s390/qeth: fix potential deadlock on
workqueue flush"), removed the code which was removed by commit
9897d583b0 ("s390/qeth: consolidate some duplicated HW cmd code").
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Bring back tls_sw_sendpage_locked. sk_msg redirection into a socket
with TLS_TX takes the following path:
tcp_bpf_sendmsg_redir
tcp_bpf_push_locked
tcp_bpf_push
kernel_sendpage_locked
sock->ops->sendpage_locked
Also update the flags test in tls_sw_sendpage_locked to allow flag
MSG_NO_SHARED_FRAGS. bpf_tcp_sendmsg sets this.
Link: https://lore.kernel.org/netdev/CA+FuTSdaAawmZ2N8nfDDKu3XLpXBbMtcCT0q4FntDD2gn8ASUw@mail.gmail.com/T/#t
Link: https://github.com/wdebruij/kerneltools/commits/icept.2
Fixes: 0608c69c9a ("bpf: sk_msg, sock{map|hash} redirect through ULP")
Fixes: f3de19af0f ("Revert \"net/tls: remove unused function tls_sw_sendpage_locked\"")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
One conflict in the BPF samples Makefile, some fixes in 'net' whilst
we were converting over to Makefile.target rules in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
TLS TX needs to release and re-acquire the socket lock if send buffer
fills up.
TLS SW TX path currently depends on only allowing one thread to enter
the function by the abuse of sk_write_pending. If another writer is
already waiting for memory no new ones are allowed in.
This has two problems:
- writers don't wake other threads up when they leave the kernel;
meaning that this scheme works for single extra thread (second
application thread or delayed work) because memory becoming
available will send a wake up request, but as Mallesham and
Pooja report with larger number of threads it leads to threads
being put to sleep indefinitely;
- the delayed work does not get _scheduled_ but it may _run_ when
other writers are present leading to crashes as writers don't
expect state to change under their feet (same records get pushed
and freed multiple times); it's hard to reliably bail from the
work, however, because the mere presence of a writer does not
guarantee that the writer will push pending records before exiting.
Ensuring wakeups always happen will make the code basically open
code a mutex. Just use a mutex.
The TLS HW TX path does not have any locking (not even the
sk_write_pending hack), yet it uses a per-socket sg_tx_data
array to push records.
Fixes: a42055e8d2 ("net/tls: Add support for async encryption of records for performance")
Reported-by: Mallesham Jatharakonda <mallesh537@gmail.com>
Reported-by: Pooja Trivedi <poojatrivedi@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sk_write_pending being not zero does not guarantee that partial
record will be pushed. If the thread waiting for memory times out
the pending record may get stuck.
In case of tls_device there is no path where parial record is
set and writer present in the first place. Partial record is
set only in tls_push_sg() and tls_push_sg() will return an
error immediately. All tls_device callers of tls_push_sg()
will return (and not wait for memory) if it failed.
Fixes: a42055e8d2 ("net/tls: Add support for async encryption of records for performance")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use a single bit instead of boolean to remember if packet
was already decrypted.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Store async_capable on a single bit instead of a full integer
to save space.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Avoid unnecessary pointer chasing and calculations, callers already
have most of the state tls_device_decrypted() needs.
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>
Add a statistic for TLS record decryption errors.
Since devices are supposed to pass records as-is when they
encounter errors this statistic will count bad records in
both pure software and inline crypto configurations.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TLS code has a number of #ifdefs which make the code a little
harder to follow. Recent fixes removed the ifdef around the
TLS_HW define, so we can switch to the often used pattern
of defining tls_device functions as empty static inlines
in the header when CONFIG_TLS_DEVICE=n.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The tls close() callback currently drops the sock lock to call
strp_done(). Split up the RX cleanup into stopping the strparser
and releasing most resources, syncing strparser and finally
freeing the context.
To avoid the need for a strp_done() call on the cleanup path
of device offload make sure we don't arm the strparser until
we are sure init will be successful.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The tls close() callback currently drops the sock lock, makes a
cancel_delayed_work_sync() call, and then relocks the sock.
By restructuring the code we can avoid droping lock and then
reclaiming it. To simplify this we do the following,
tls_sk_proto_close
set_bit(CLOSING)
set_bit(SCHEDULE)
cancel_delay_work_sync() <- cancel workqueue
lock_sock(sk)
...
release_sock(sk)
strp_done()
Setting the CLOSING bit prevents the SCHEDULE bit from being
cleared by any workqueue items e.g. if one happens to be
scheduled and run between when we set SCHEDULE bit and cancel
work. Then because SCHEDULE bit is set now no new work will
be scheduled.
Tested with net selftests and bpf selftests.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
In tls_set_device_offload_rx() we prepare the software context
for RX fallback and proceed to add the connection to the device.
Unfortunately, software context prep includes arming strparser
so in case of a later error we have to release the socket lock
to call strp_done().
In preparation for not releasing the socket lock half way through
callbacks move arming strparser into a separate function.
Following patches will make use of that.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
David reports that RPC applications which use epoll() occasionally
get stuck, and that TLS ULP causes the kernel to not wake applications,
even though read() will return data.
This is indeed true. The ctx->rx_list which holds partially copied
records is not consulted when deciding whether socket is readable.
Note that SO_RCVLOWAT with epoll() is and has always been broken for
kernel TLS. We'd need to parse all records from the TCP layer, instead
of just the first one.
Fixes: 692d7b5d1f ("tls: Fix recvmsg() to be able to peek across multiple records")
Reported-by: David Beckett <david.beckett@netronome.com>
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>
tls_sw_do_sendpage needs to return the total number of bytes sent
regardless of how many sk_msgs are allocated. Unfortunately, copied
(the value we return up the stack) is zero'd before each new sk_msg
is allocated so we only return the copied size of the last sk_msg used.
The caller (splice, etc.) of sendpage will then believe only part
of its data was sent and send the missing chunks again. However,
because the data actually was sent the receiver will get multiple
copies of the same data.
To reproduce this do multiple sendfile calls with a length close to
the max record size. This will in turn call splice/sendpage, sendpage
may use multiple sk_msg in this case and then returns the incorrect
number of bytes. This will cause splice to resend creating duplicate
data on the receiver. Andre created a C program that can easily
generate this case so we will push a similar selftest for this to
bpf-next shortly.
The fix is to _not_ zero the copied field so that the total sent
bytes is returned.
Reported-by: Steinar H. Gunderson <steinar+kernel@gunderson.no>
Reported-by: Andre Tomt <andre@tomt.net>
Tested-by: Andre Tomt <andre@tomt.net>
Fixes: d829e9c411 ("tls: convert to generic sk_msg interface")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TLS offload device may lose sync with the TCP stream if packets
arrive out of order. Drivers can currently request a resync at
a specific TCP sequence number. When a record is found starting
at that sequence number kernel will inform the device of the
corresponding record number.
This requires the device to constantly scan the stream for a
known pattern (constant bytes of the header) after sync is lost.
This patch adds an alternative approach which is entirely under
the control of the kernel. Kernel tracks records it had to fully
decrypt, even though TLS socket is in TLS_HW mode. If multiple
records did not have any decrypted parts - it's a pretty strong
indication that the device is out of sync.
We choose the min number of fully encrypted records to be 2,
which should hopefully be more than will get retransmitted at
a time.
After kernel decides the device is out of sync it schedules a
resync request. If the TCP socket is empty the resync gets
performed immediately. If socket is not empty we leave the
record parser to resync when next record comes.
Before resync in message parser we peek at the TCP socket and
don't attempt the sync if the socket already has some of the
next record queued.
On resync failure (encrypted data continues to flow in) we
retry with exponential backoff, up to once every 128 records
(with a 16k record thats at most once every 2M of data).
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>
handle_device_resync() doesn't describe the function very well.
The function checks if resync should be issued upon parsing of
a new record.
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>
TLS offload code casts record number to a u64. The buffer
should be aligned to 8 bytes, but its actually a __be64, and
the rest of the TLS code treats it as big int. Make the
offload callbacks take a byte array, drivers can make the
choice to do the ugly cast if they want to.
Prepare for copying the record number onto the stack by
defining a constant for max size of the byte array.
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>
All callers pass prot->version as the last parameter
of tls_advance_record_sn(), yet tls_advance_record_sn()
itself needs a pointer to prot. Pass prot from callers.
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>
If the RX config of a TLS socket is SW, there is no point iterating
over the fragments and checking if frame is decrypted. It will
always be fully encrypted. Note that in fully encrypted case
the function doesn't actually touch any offload-related state,
so it's safe to call for TLS_SW, today. Soon we will introduce
code which can only be called for offloaded contexts.
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>
When tls_sw_recvmsg() partially copies a record it pops that
record from ctx->recv_pkt and places it on rx_list.
Next iteration of tls_sw_recvmsg() reads from rx_list via
process_rx_list() before it enters the decryption loop.
If there is no more records to be read tls_wait_data()
will put the process on the wait queue and got to sleep.
This is incorrect, because some data was already copied
in process_rx_list().
In case of RPC connections process may never get woken up,
because peer also simply blocks in read().
I think this may also fix a similar issue when BPF is at
play, because after __tcp_bpf_recvmsg() returns some data
we subtract it from len and use continue to restart the
loop, but len could have just reached 0, so again we'd
sleep unnecessarily. That's added by:
commit d3b18ad31f ("tls: add bpf support to sk_msg handling")
Fixes: 692d7b5d1f ("tls: Fix recvmsg() to be able to peek across multiple records")
Reported-by: David Beckett <david.beckett@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Tested-by: David Beckett <david.beckett@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If some of the data came from the previous record, i.e. from
the rx_list it had already been decrypted, so it's not counted
towards the "decrypted" variable, but the "copied" variable.
Take that into account when checking lowat.
When calculating lowat target we need to pass the original len.
E.g. if lowat is at 80, len is 100 and we had 30 bytes on rx_list
target would currently be incorrectly calculated as 70, even though
we only need 50 more bytes to make up the 80.
Fixes: 692d7b5d1f ("tls: Fix recvmsg() to be able to peek across multiple records")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Tested-by: David Beckett <david.beckett@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
At the time padding_length() is called the record header
is still part of the message. If malicious TLS 1.3 peer
sends an all-zero record padding_length() will stop at
the record header, and return full length of the data
including the tail_size.
Subsequent subtraction of prot->overhead_size from rxm->full_len
will cause rxm->full_len to turn negative. skb accessors,
however, will always catch resulting out-of-bounds operation,
so in practice this fix comes down to returning the correct
error code. It also fixes a set but not used warning.
This code was added by commit 130b392c6c ("net: tls: Add tls 1.3 support").
CC: Dave Watson <davejwatson@fb.com>
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>
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>
David reports that tls triggers warnings related to
sk->sk_forward_alloc not being zero at destruction time:
WARNING: CPU: 5 PID: 6831 at net/core/stream.c:206 sk_stream_kill_queues+0x103/0x110
WARNING: CPU: 5 PID: 6831 at net/ipv4/af_inet.c:160 inet_sock_destruct+0x15b/0x170
When sender fills up the write buffer and dies from
SIGPIPE. This is due to the device implementation
not cleaning up the partially_sent_record.
This is because commit a42055e8d2 ("net/tls: Add support for async encryption of records for performance")
moved the partial record cleanup to the SW-only path.
Fixes: a42055e8d2 ("net/tls: Add support for async encryption of records for performance")
Reported-by: David Beckett <david.beckett@netronome.com>
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>
Minor comment merge conflict in mlx5.
Staging driver has a fixup due to the skb->xmit_more changes
in 'net-next', but was removed in 'net'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Only decrypt_internal() performs zero copy on rx, all paths
which don't hit decrypt_internal() must set zc to false,
otherwise tls_sw_recvmsg() may return 0 causing the application
to believe that that connection got closed.
Currently this happens with device offload when new record
is first read from.
Fixes: d069b780e3 ("tls: Fix tls_device receive")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reported-by: David Beckett <david.beckett@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To free the skb in normal course of processing, consume_skb() should be
used. Only for failure paths, skb_free() is intended to be used.
https://www.kernel.org/doc/htmldocs/networking/API-consume-skb.html
Signed-off-by: Vakul Garg <vakul.garg@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Added support for AES128-CCM based record encryption. AES128-CCM is
similar to AES128-GCM. Both of them have same salt/iv/mac size. The
notable difference between the two is that while invoking AES128-CCM
operation, the salt||nonce (which is passed as IV) has to be prefixed
with a hardcoded value '2'. Further, CCM implementation in kernel
requires IV passed in crypto_aead_request() to be full '16' bytes.
Therefore, the record structure 'struct tls_rec' has been modified to
reserve '16' bytes for IV. This works for both GCM and CCM based cipher.
Signed-off-by: Vakul Garg <vakul.garg@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
