Artem points out that skb may try to take over the skb and
queue it to its own list. Unlink the skb before calling out.
Fixes: b1a2c17863 ("tls: rx: clear ctx->recv_pkt earlier")
Reported-by: Artem Savkov <asavkov@redhat.com>
Tested-by: Artem Savkov <asavkov@redhat.com>
Link: https://lore.kernel.org/r/20220518205644.2059468-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
TLS device offload copies sendfile data to a bounce buffer before
transmitting. It allows to maintain the valid MAC on TLS records when
the file contents change and a part of TLS record has to be
retransmitted on TCP level.
In many common use cases (like serving static files over HTTPS) the file
contents are not changed on the fly. In many use cases breaking the
connection is totally acceptable if the file is changed during
transmission, because it would be received corrupted in any case.
This commit allows to optimize performance for such use cases to
providing a new optional mode of TLS sendfile(), in which the extra copy
is skipped. Removing this copy improves performance significantly, as
TLS and TCP sendfile perform the same operations, and the only overhead
is TLS header/trailer insertion.
The new mode can only be enabled with the new socket option named
TLS_TX_ZEROCOPY_SENDFILE on per-socket basis. It preserves backwards
compatibility with existing applications that rely on the copying
behavior.
The new mode is safe, meaning that unsolicited modifications of the file
being sent can't break integrity of the kernel. The worst thing that can
happen is sending a corrupted TLS record, which is in any case not
forbidden when using regular TCP sockets.
Sockets other than TLS device offload are not affected by the new socket
option. The actual status of zerocopy sendfile can be queried with
sock_diag.
Performance numbers in a single-core test with 24 HTTPS streams on
nginx, under 100% CPU load:
* non-zerocopy: 33.6 Gbit/s
* zerocopy: 79.92 Gbit/s
CPU: Intel(R) Xeon(R) Platinum 8380 CPU @ 2.30GHz
Signed-off-by: Boris Pismenny <borisp@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20220518092731.1243494-1-maximmi@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The commit cited below claims to fix a use-after-free condition after
tls_device_down. Apparently, the description wasn't fully accurate. The
context stayed alive, but ctx->netdev became NULL, and the offload was
torn down without a proper fallback, so a bug was present, but a
different kind of bug.
Due to misunderstanding of the issue, the original patch dropped the
refcount_dec_and_test line for the context to avoid the alleged
premature deallocation. That line has to be restored, because it matches
the refcount_inc_not_zero from the same function, otherwise the contexts
that survived tls_device_down are leaked.
This patch fixes the described issue by restoring refcount_dec_and_test.
After this change, there is no leak anymore, and the fallback to
software kTLS still works.
Fixes: c55dcdd435 ("net/tls: Fix use-after-free after the TLS device goes down and up")
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/20220512091830.678684-1-maximmi@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Calling tls_append_frag when max_open_record_len == record->len might
add an empty fragment to the TLS record if the call happens to be on the
page boundary. Normally tls_append_frag coalesces the zero-sized
fragment to the previous one, but not if it's on page boundary.
If a resync happens then, the mlx5 driver posts dump WQEs in
tx_post_resync_dump, and the empty fragment may become a data segment
with byte_count == 0, which will confuse the NIC and lead to a CQE
error.
This commit fixes the described issue by skipping tls_append_frag on
zero size to avoid adding empty fragments. The fix is not in the driver,
because an empty fragment is hardly the desired behavior.
Fixes: e8f6979981 ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/20220426154949.159055-1-maximmi@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When NIC takes care of crypto (or the record has already
been decrypted) we forget to update darg->async. ->async
is supposed to mean whether record is async capable on
input and whether record has been queued for async crypto
on output.
Reported-by: Gal Pressman <gal@nvidia.com>
Fixes: 3547a1f9d9 ("tls: rx: use async as an in-out argument")
Tested-by: Gal Pressman <gal@nvidia.com>
Link: https://lore.kernel.org/r/20220425233309.344858-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Logic added in commit f35f821935 ("tcp: defer skb freeing after socket
lock is released") helped bulk TCP flows to move the cost of skbs
frees outside of critical section where socket lock was held.
But for RPC traffic, or hosts with RFS enabled, the solution is far from
being ideal.
For RPC traffic, recvmsg() has to return to user space right after
skb payload has been consumed, meaning that BH handler has no chance
to pick the skb before recvmsg() thread. This issue is more visible
with BIG TCP, as more RPC fit one skb.
For RFS, even if BH handler picks the skbs, they are still picked
from the cpu on which user thread is running.
Ideally, it is better to free the skbs (and associated page frags)
on the cpu that originally allocated them.
This patch removes the per socket anchor (sk->defer_list) and
instead uses a per-cpu list, which will hold more skbs per round.
This new per-cpu list is drained at the end of net_action_rx(),
after incoming packets have been processed, to lower latencies.
In normal conditions, skbs are added to the per-cpu list with
no further action. In the (unlikely) cases where the cpu does not
run net_action_rx() handler fast enough, we use an IPI to raise
NET_RX_SOFTIRQ on the remote cpu.
Also, we do not bother draining the per-cpu list from dev_cpu_dead()
This is because skbs in this list have no requirement on how fast
they should be freed.
Note that we can add in the future a small per-cpu cache
if we see any contention on sd->defer_lock.
Tested on a pair of hosts with 100Gbit NIC, RFS enabled,
and /proc/sys/net/ipv4/tcp_rmem[2] tuned to 16MB to work around
page recycling strategy used by NIC driver (its page pool capacity
being too small compared to number of skbs/pages held in sockets
receive queues)
Note that this tuning was only done to demonstrate worse
conditions for skb freeing for this particular test.
These conditions can happen in more general production workload.
10 runs of one TCP_STREAM flow
Before:
Average throughput: 49685 Mbit.
Kernel profiles on cpu running user thread recvmsg() show high cost for
skb freeing related functions (*)
57.81% [kernel] [k] copy_user_enhanced_fast_string
(*) 12.87% [kernel] [k] skb_release_data
(*) 4.25% [kernel] [k] __free_one_page
(*) 3.57% [kernel] [k] __list_del_entry_valid
1.85% [kernel] [k] __netif_receive_skb_core
1.60% [kernel] [k] __skb_datagram_iter
(*) 1.59% [kernel] [k] free_unref_page_commit
(*) 1.16% [kernel] [k] __slab_free
1.16% [kernel] [k] _copy_to_iter
(*) 1.01% [kernel] [k] kfree
(*) 0.88% [kernel] [k] free_unref_page
0.57% [kernel] [k] ip6_rcv_core
0.55% [kernel] [k] ip6t_do_table
0.54% [kernel] [k] flush_smp_call_function_queue
(*) 0.54% [kernel] [k] free_pcppages_bulk
0.51% [kernel] [k] llist_reverse_order
0.38% [kernel] [k] process_backlog
(*) 0.38% [kernel] [k] free_pcp_prepare
0.37% [kernel] [k] tcp_recvmsg_locked
(*) 0.37% [kernel] [k] __list_add_valid
0.34% [kernel] [k] sock_rfree
0.34% [kernel] [k] _raw_spin_lock_irq
(*) 0.33% [kernel] [k] __page_cache_release
0.33% [kernel] [k] tcp_v6_rcv
(*) 0.33% [kernel] [k] __put_page
(*) 0.29% [kernel] [k] __mod_zone_page_state
0.27% [kernel] [k] _raw_spin_lock
After patch:
Average throughput: 73076 Mbit.
Kernel profiles on cpu running user thread recvmsg() looks better:
81.35% [kernel] [k] copy_user_enhanced_fast_string
1.95% [kernel] [k] _copy_to_iter
1.95% [kernel] [k] __skb_datagram_iter
1.27% [kernel] [k] __netif_receive_skb_core
1.03% [kernel] [k] ip6t_do_table
0.60% [kernel] [k] sock_rfree
0.50% [kernel] [k] tcp_v6_rcv
0.47% [kernel] [k] ip6_rcv_core
0.45% [kernel] [k] read_tsc
0.44% [kernel] [k] _raw_spin_lock_irqsave
0.37% [kernel] [k] _raw_spin_lock
0.37% [kernel] [k] native_irq_return_iret
0.33% [kernel] [k] __inet6_lookup_established
0.31% [kernel] [k] ip6_protocol_deliver_rcu
0.29% [kernel] [k] tcp_rcv_established
0.29% [kernel] [k] llist_reverse_order
v2: kdoc issue (kernel bots)
do not defer if (alloc_cpu == smp_processor_id()) (Paolo)
replace the sk_buff_head with a single-linked list (Jakub)
add a READ_ONCE()/WRITE_ONCE() for the lockless read of sd->defer_list
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20220422201237.416238-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
TLS 1.3 and ChaChaPoly don't carry IV in the packet.
The code before this change would copy out iv_size
worth of whatever followed the TLS header in the packet
and then for TLS 1.3 | ChaCha overwrite that with
the sequence number. Waste of cycles especially
with TLS 1.2 being close to dead and TLS 1.3 being
the common case.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
IVs are 8 or 16 bytes, no point reading out the exact value
for quantities this small.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Propagating EINPROGRESS thru multiple layers of functions is
error prone. Use darg->async as an in/out argument, like we
use darg->zc today. On input it tells the code if async is
allowed, on output if it took place.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
async crypto handler will report the socket error no need
to report it again. We can, however, let the data we already
copied be reported to user space but we need to make sure
the error will be reported next time around.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
process_rx_list() only fails if it can't copy data to user
space. There is no point recording the error onto sk->sk_err
or giving up on the data which was read partially. Treat
the return value like a normal socket partial read.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If crypto didn't always invoke our callback for async
we'd not be clearing skb->sk and would crash in the
skb core when freeing it. This if must be dead code.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Async crypto never worked with TLS 1.3 and was explicitly disabled in
commit 8497ded2d1 ("net/tls: Disable async decrytion for tls1.3").
There's no need for us to handle TLS 1.3 padding in the async cb.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move counting TlsDecryptErrors to tls_do_decryption()
where differences between sync and async crypto are
reconciled.
No functional changes, this code just always gave
me a pause.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
rx_list is protected by the socket lock, no need to take
the built-in spin lock on accesses.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The internal recvmsg() functions have two parameters 'flags' and 'noblock'
that were merged inside skb_recv_datagram(). As a follow up patch to commit
f4b41f062c ("net: remove noblock parameter from skb_recv_datagram()")
this patch removes the separate 'noblock' parameter for recvmsg().
Analogue to the referenced patch for skb_recv_datagram() the 'flags' and
'noblock' parameters are unnecessarily split up with e.g.
err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
flags & ~MSG_DONTWAIT, &addr_len);
or in
err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
sk, msg, size, flags & MSG_DONTWAIT,
flags & ~MSG_DONTWAIT, &addr_len);
instead of simply using only flags all the time and check for MSG_DONTWAIT
where needed (to preserve for the formerly separated no(n)block condition).
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20220411124955.154876-1-socketcan@hartkopp.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The current invese logic is harder to follow (and adds extra
tests to the fast path). We have to enumerate all cases which
need to keep the skb before consuming it. It's simpler to
jump out of the full record flow as we detect those cases.
This makes it clear that partial consumption and peek can
only reach end of the function thru the !zc case so move
the code up there.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Whatever we do in the loop the skb should not remain on as
ctx->recv_pkt afterwards. We can clear that pointer and
restart strparser earlier.
This adds overhead of extra linking and unlinking to rx_list
but that's not large (upcoming change will switch to unlocked
skb list operations).
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
tls_sw_advance_skb() always consumes the skb at the end of the loop.
To fall here the following must be true:
!async && !is_peek && !retain_skb
retain_skb => !zc && rxm->full_len > len
# but non-full record implies !zc, so above can be simplified as
retain_skb => rxm->full_len > len
!async && !is_peek && !(rxm->full_len > len)
!async && !is_peek && rxm->full_len <= len
tls_sw_advance_skb() returns false if len < rxm->full_len
which can't be true given conditions above.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Most of the conditions deciding if zero-copy can be used
do not change throughout the iterations, so pre-calculate
them.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We track both if the last record was handled by async crypto
and how many records were async. This is not necessary. We
implicitly assume once crypto goes async it will stay that
way, otherwise we'd reorder records. So just track if we're
in async mode, the exact number of records is not necessary.
This change also forces us into "async" mode more consistently
in case crypto ever decided to interleave async and sync.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
tls_sw_advance_skb() caters to the async case when skb argument
is NULL. In that case it simply unpauses the strparser.
These are surprising semantics to a person reading the code,
and result in higher LoC, so inline the __strp_unpause and
only call tls_sw_advance_skb() when we actually move past
an skb.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
cmsg can be filled in during rx_list processing or normal
receive. Consolidate the code.
We don't need to keep the boolean to track if the cmsg was
created. 0 is an invalid content type.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since we are protected from async completions by decrypt_compl_lock
we can drop the async_notify and reinit the completion before we
start waiting.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We pass zc as a pointer to bool a few functions down as an in/out
argument. This is error prone since C will happily evalue a pointer
as a boolean (IOW forgetting *zc and writing zc leads to loss of
developer time..). Wrap the arguments into a structure.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We plumb pointer to chunk all the way to the decryption method.
It's set to the length of the text when decrypt_skb_update()
returns.
I think the code is written this way because original TLS
implementation passed &chunk to zerocopy_from_iter() and this
was carried forward as the code gotten more complex, without
any refactoring.
The fix for peek() introduced a new variable - to_decrypt
which for all practical purposes is what chunk is going to
get set to. Spare ourselves the pointer passing, use to_decrypt.
Use this opportunity to clean things up a little further.
Note that chunk / to_decrypt was mostly needed for the async
path, since the sync path would access rxm->full_len (decryption
transforms full_len from record size to text size). Use the
right source of truth more explicitly.
We have three cases:
- async - it's TLS 1.2 only, so chunk == to_decrypt, but we
need the min() because to_decrypt is a whole record
and we don't want to underflow len. Note that we can't
handle partial record by falling back to sync as it
would introduce reordering against records in flight.
- zc - again, TLS 1.2 only for now, so chunk == to_decrypt,
we don't do zc if len < to_decrypt, no need to check again.
- normal - it already handles chunk > len, we can factor out the
assignment to rxm->full_len and share it with zc.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
sk is unused, remove it to make it clear the function
doesn't poke at the socket.
size_used is always 0 on input and @length on success.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of tls_device poking into internals of the message
return 1 from tls_device_decrypted() if the device handled
the decryption.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use early return and a jump label to remove two indentation levels.
No functional changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We inform the applications that data is available when
the record is received. Decryption happens inline inside
recvmsg or splice call. Generating another wakeup inside
the decryption handler seems pointless as someone must
be actively reading the socket if we are executing this
code.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The padding length TLS 1.3 logic is searching for content_type from
the end of text. IMHO the code is easier to parse if we calculate
offset and decrement it rather than try to maintain positive offset
from the end of the record called "back".
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
TLS 1.3 has to strip padding, and it starts out 16 bytes
from the end of the record. Make it clear this is because
of the auth tag.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We set the record type in tls_read_size(), can as well init
the tlm->decrypted field there.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Similar justification to previous change, the information
about decryption status belongs in the skb.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Original TLS implementation was handling one record at a time.
It stashed the type of the record inside tls context (per socket
structure) for convenience. When async crypto support was added
[1] the author had to use skb->cb to store the type per-message.
The use of skb->cb overlaps with strparser, however, so a hybrid
approach was taken where type is stored in context while parsing
(since we parse a message at a time) but once parsed its copied
to skb->cb.
Recently a workaround for sockmaps [2] exposed the previously
private struct _strp_msg and started a trend of adding user
fields directly in strparser's header. This is cleaner than
storing information about an skb in the context.
This change is not strictly necessary, but IMHO the ownership
of the context field is confusing. Information naturally
belongs to the skb.
[1] commit 94524d8fc9 ("net/tls: Add support for async decryption of tls records")
[2] commit b2c4618162 ("bpf, sockmap: sk_skb data_end access incorrect when src_reg = dst_reg")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pointless else branch after goto makes the code harder to refactor
down the line.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
'recv_end:' checks num_async and decrypted, and is then followed
by the 'end' label. Since we know that decrypted and num_async
are 0 at the start we can jump to 'end'.
Move the init of decrypted and num_async to let the compiler
catch if I'm wrong.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The memory size of tls_ctx->rx.iv for AES128-CCM is 12 setting in
tls_set_sw_offload(). The return value of crypto_aead_ivsize()
for "ccm(aes)" is 16. So memcpy() require 16 bytes from 12 bytes
memory space will trigger slab-out-of-bounds bug as following:
==================================================================
BUG: KASAN: slab-out-of-bounds in decrypt_internal+0x385/0xc40 [tls]
Read of size 16 at addr ffff888114e84e60 by task tls/10911
Call Trace:
<TASK>
dump_stack_lvl+0x34/0x44
print_report.cold+0x5e/0x5db
? decrypt_internal+0x385/0xc40 [tls]
kasan_report+0xab/0x120
? decrypt_internal+0x385/0xc40 [tls]
kasan_check_range+0xf9/0x1e0
memcpy+0x20/0x60
decrypt_internal+0x385/0xc40 [tls]
? tls_get_rec+0x2e0/0x2e0 [tls]
? process_rx_list+0x1a5/0x420 [tls]
? tls_setup_from_iter.constprop.0+0x2e0/0x2e0 [tls]
decrypt_skb_update+0x9d/0x400 [tls]
tls_sw_recvmsg+0x3c8/0xb50 [tls]
Allocated by task 10911:
kasan_save_stack+0x1e/0x40
__kasan_kmalloc+0x81/0xa0
tls_set_sw_offload+0x2eb/0xa20 [tls]
tls_setsockopt+0x68c/0x700 [tls]
__sys_setsockopt+0xfe/0x1b0
Replace the crypto_aead_ivsize() with prot->iv_size + prot->salt_size
when memcpy() iv value in TLS_1_3_VERSION scenario.
Fixes: f295b3ae9f ("net/tls: Add support of AES128-CCM based ciphers")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
It is known that priority setting HW offload when set tls TX/RX offload
by setsockopt(). Check netdevice whether support NETIF_F_HW_TLS_TX or
not at the later stages in the whole tls_set_device_offload() process,
some memory allocations have been done before that. We must release those
memory and return error if we judge the netdevice not support
NETIF_F_HW_TLS_TX. It is redundant.
Move NETIF_F_HW_TLS_TX judgement forward, and move start_marker_record
and offload_ctx memory allocation back slightly. Thus, we can get
simpler exception handling process.
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Avoid using "goto" jump instruction unconditionally when we
can return directly. Remove unnecessary jump instructions in
do_tls_setsockopt_conf().
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
TLS recvmsg() passes user pages as destination for decrypt.
The decrypt operation is repeated record by record, each
record being 16kB, max. TLS allocates an sg_table and uses
iov_iter_get_pages() to populate it with enough pages to
fit the decrypted record.
Even though we decrypt a single message at a time we size
the sg_table based on the entire length of the iovec.
This leads to unnecessarily large allocations, risking
triggering OOM conditions.
Use iov_iter_truncate() / iov_iter_reexpand() to construct
a "capped" version of iov_iter_npages(). Alternatively we
could parametrize iov_iter_npages() to take the size as
arg instead of using i->count, or do something else..
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is a followup to
commit ffef737fd0 ("net/tls: Fix skb memory leak when running kTLS traffic")
Which was missing another sk_defer_free_flush() call in
tls_sw_splice_read().
Fixes: f35f821935 ("tcp: defer skb freeing after socket lock is released")
Signed-off-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The cited Fixes commit introduced a memory leak when running kTLS
traffic (with/without hardware offloads).
I'm running nginx on the server side and wrk on the client side and get
the following:
unreferenced object 0xffff8881935e9b80 (size 224):
comm "softirq", pid 0, jiffies 4294903611 (age 43.204s)
hex dump (first 32 bytes):
80 9b d0 36 81 88 ff ff 00 00 00 00 00 00 00 00 ...6............
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000efe2a999>] build_skb+0x1f/0x170
[<00000000ef521785>] mlx5e_skb_from_cqe_mpwrq_linear+0x2bc/0x610 [mlx5_core]
[<00000000945d0ffe>] mlx5e_handle_rx_cqe_mpwrq+0x264/0x9e0 [mlx5_core]
[<00000000cb675b06>] mlx5e_poll_rx_cq+0x3ad/0x17a0 [mlx5_core]
[<0000000018aac6a9>] mlx5e_napi_poll+0x28c/0x1b60 [mlx5_core]
[<000000001f3369d1>] __napi_poll+0x9f/0x560
[<00000000cfa11f72>] net_rx_action+0x357/0xa60
[<000000008653b8d7>] __do_softirq+0x282/0x94e
[<00000000644923c6>] __irq_exit_rcu+0x11f/0x170
[<00000000d4085f8f>] irq_exit_rcu+0xa/0x20
[<00000000d412fef4>] common_interrupt+0x7d/0xa0
[<00000000bfb0cebc>] asm_common_interrupt+0x1e/0x40
[<00000000d80d0890>] default_idle+0x53/0x70
[<00000000f2b9780e>] default_idle_call+0x8c/0xd0
[<00000000c7659e15>] do_idle+0x394/0x450
I'm not familiar with these areas of the code, but I've added this
sk_defer_free_flush() to tls_sw_recvmsg() based on a hunch and it
resolved the issue.
Fixes: f35f821935 ("tcp: defer skb freeing after socket lock is released")
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220102081253.9123-1-gal@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Assigning crypto_info variables in advance can simplify the logic
of accessing value and move related local variables to a smaller
scope.
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the TLS cipher suite uses CCM mode, including AES CCM and
SM4 CCM, the first byte of the B0 block is flags, and the real
IV starts from the second byte. The XOR operation of the IV and
rec_seq should be skip this byte, that is, add the iv_offset.
Fixes: f295b3ae9f ("net/tls: Add support of AES128-CCM based ciphers")
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Cc: Vakul Garg <vakul.garg@nxp.com>
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: David S. Miller <davem@davemloft.net>
We replace proto_ops whenever TLS is configured for RX. But our
replacement also overrides sendpage_locked, which will crash
unless TX is also configured. Similarly we plug both of those
in for TLS_HW (NIC crypto offload) even tho TLS_HW has a completely
different implementation for TX.
Last but not least we always plug in something based on inet_stream_ops
even though a few of the callbacks differ for IPv6 (getname, release,
bind).
Use a callback building method similar to what we do for struct proto.
Fixes: c46234ebb4 ("tls: RX path for ktls")
Fixes: d4ffb02dee ("net/tls: enable sk_msg redirect to tls socket egress")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
