Commit Graph

202 Commits

Author SHA1 Message Date
John Fastabend d85f017758 net: tls, fix sk_write_space NULL write when tx disabled
The ctx->sk_write_space pointer is only set when TLS tx mode is enabled.
When running without TX mode its a null pointer but we still set the
sk sk_write_space pointer on close().

Fix the close path to only overwrite sk->sk_write_space when the current
pointer is to the tls_write_space function indicating the tls module should
clean it up properly as well.

Reported-by: Hillf Danton <hdanton@sina.com>
Cc: Ying Xue <ying.xue@windriver.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Fixes: 57c722e932 ("net/tls: swap sk_write_space on close")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-15 12:40:15 -07:00
Jakub Kicinski 57c722e932 net/tls: swap sk_write_space on close
Now that we swap the original proto and clear the ULP pointer
on close we have to make sure no callback will try to access
the freed state. sk_write_space is not part of sk_prot, remember
to swap it.

Reported-by: syzbot+dcdc9deefaec44785f32@syzkaller.appspotmail.com
Fixes: 95fa145479 ("bpf: sockmap/tls, close can race with map free")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-09 19:55:22 -07:00
Jakub Kicinski 414776621d net/tls: prevent skb_orphan() from leaking TLS plain text with offload
sk_validate_xmit_skb() and drivers depend on the sk member of
struct sk_buff to identify segments requiring encryption.
Any operation which removes or does not preserve the original TLS
socket such as skb_orphan() or skb_clone() will cause clear text
leaks.

Make the TCP socket underlying an offloaded TLS connection
mark all skbs as decrypted, if TLS TX is in offload mode.
Then in sk_validate_xmit_skb() catch skbs which have no socket
(or a socket with no validation) and decrypted flag set.

Note that CONFIG_SOCK_VALIDATE_XMIT, CONFIG_TLS_DEVICE and
sk->sk_validate_xmit_skb are slightly interchangeable right now,
they all imply TLS offload. The new checks are guarded by
CONFIG_TLS_DEVICE because that's the option guarding the
sk_buff->decrypted member.

Second, smaller issue with orphaning is that it breaks
the guarantee that packets will be delivered to device
queues in-order. All TLS offload drivers depend on that
scheduling property. This means skb_orphan_partial()'s
trick of preserving partial socket references will cause
issues in the drivers. We need a full orphan, and as a
result netem delay/throttling will cause all TLS offload
skbs to be dropped.

Reusing the sk_buff->decrypted flag also protects from
leaking clear text when incoming, decrypted skb is redirected
(e.g. by TC).

See commit 0608c69c9a ("bpf: sk_msg, sock{map|hash} redirect
through ULP") for justification why the internal flag is safe.
The only location which could leak the flag in is tcp_bpf_sendmsg(),
which is taken care of by clearing the previously unused bit.

v2:
 - remove superfluous decrypted mark copy (Willem);
 - remove the stale doc entry (Boris);
 - rely entirely on EOR marking to prevent coalescing (Boris);
 - use an internal sendpages flag instead of marking the socket
   (Boris).
v3 (Willem):
 - reorganize the can_skb_orphan_partial() condition;
 - fix the flag leak-in through tcp_bpf_sendmsg.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-08 22:39:35 -07:00
Jakub Kicinski 5d92e631b8 net/tls: partially revert fix transition through disconnect with close
Looks like we were slightly overzealous with the shutdown()
cleanup. Even though the sock->sk_state can reach CLOSED again,
socket->state will not got back to SS_UNCONNECTED once
connections is ESTABLISHED. Meaning we will see EISCONN if
we try to reconnect, and EINVAL if we try to listen.

Only listen sockets can be shutdown() and reused, but since
ESTABLISHED sockets can never be re-connected() or used for
listen() we don't need to try to clean up the ULP state early.

Fixes: 32857cf57f ("net/tls: fix transition through disconnect with close")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-05 13:15:30 -07:00
John Fastabend 95fa145479 bpf: sockmap/tls, close can race with map free
When a map free is called and in parallel a socket is closed we
have two paths that can potentially reset the socket prot ops, the
bpf close() path and the map free path. This creates a problem
with which prot ops should be used from the socket closed side.

If the map_free side completes first then we want to call the
original lowest level ops. However, if the tls path runs first
we want to call the sockmap ops. Additionally there was no locking
around prot updates in TLS code paths so the prot ops could
be changed multiple times once from TLS path and again from sockmap
side potentially leaving ops pointed at either TLS or sockmap
when psock and/or tls context have already been destroyed.

To fix this race first only update ops inside callback lock
so that TLS, sockmap and lowest level all agree on prot state.
Second and a ULP callback update() so that lower layers can
inform the upper layer when they are being removed allowing the
upper layer to reset prot ops.

This gets us close to allowing sockmap and tls to be stacked
in arbitrary order but will save that patch for *next trees.

v4:
 - make sure we don't free things for device;
 - remove the checks which swap the callbacks back
   only if TLS is at the top.

Reported-by: syzbot+06537213db7ba2745c4a@syzkaller.appspotmail.com
Fixes: 02c558b2d5 ("bpf: sockmap, support for msg_peek in sk_msg with redirect ingress")
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>
2019-07-22 16:04:17 +02:00
John Fastabend 32857cf57f net/tls: fix transition through disconnect with close
It is possible (via shutdown()) for TCP socks to go through TCP_CLOSE
state via tcp_disconnect() without actually calling tcp_close which
would then call the tls close callback. Because of this a user could
disconnect a socket then put it in a LISTEN state which would break
our assumptions about sockets always being ESTABLISHED state.

More directly because close() can call unhash() and unhash is
implemented by sockmap if a sockmap socket has TLS enabled we can
incorrectly destroy the psock from unhash() and then call its close
handler again. But because the psock (sockmap socket representation)
is already destroyed we call close handler in sk->prot. However,
in some cases (TLS BASE/BASE case) this will still point at the
sockmap close handler resulting in a circular call and crash reported
by syzbot.

To fix both above issues implement the unhash() routine for TLS.

v4:
 - add note about tls offload still needing the fix;
 - move sk_proto to the cold cache line;
 - split TX context free into "release" and "free",
   otherwise the GC work itself is in already freed
   memory;
 - more TX before RX for consistency;
 - reuse tls_ctx_free();
 - schedule the GC work after we're done with context
   to avoid UAF;
 - don't set the unhash in all modes, all modes "inherit"
   TLS_BASE's callbacks anyway;
 - disable the unhash hook for TLS_HW.

Fixes: 3c4d755915 ("tls: kernel TLS support")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-22 16:04:17 +02:00
John Fastabend 313ab00480 net/tls: remove sock unlock/lock around strp_done()
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>
2019-07-22 16:04:16 +02:00
John Fastabend f87e62d45e net/tls: remove close callback sock unlock/lock around TX work flush
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>
2019-07-22 16:04:16 +02:00
Jakub Kicinski ac78fc148d net/tls: don't call tls_sk_proto_close for hw record offload
The deprecated TOE offload doesn't actually do anything in
tls_sk_proto_close() - all TLS code is skipped and context
not freed. Remove the callback to make it easier to refactor
tls_sk_proto_close().

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>
2019-07-22 16:04:16 +02:00
Jakub Kicinski 318892ac06 net/tls: don't arm strparser immediately in tls_set_sw_offload()
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>
2019-07-22 16:04:16 +02:00
Jakub Kicinski 5c4b4608fe net/tls: fix socket wmem accounting on fallback with netem
netem runs skb_orphan_partial() which "disconnects" the skb
from normal TCP write memory accounting.  We should not adjust
sk->sk_wmem_alloc on the fallback path for such skbs.

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>
2019-07-08 20:21:10 -07:00
Jakub Kicinski ab232e61e7 net/tls: add missing prot info init
Turns out TLS_TX in HW offload mode does not initialize tls_prot_info.
Since commit 9cd81988cc ("net/tls: use version from prot") we actually
use this field on the datapath.  Luckily we always compare it to TLS 1.3,
and assume 1.2 otherwise. So since zero is not equal to 1.3, everything
worked fine.

Fixes: 9cd81988cc ("net/tls: use version from prot")
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>
2019-07-08 20:21:09 -07:00
Dirk van der Merwe b5d9a834f4 net/tls: don't clear TX resync flag on error
Introduce a return code for the tls_dev_resync callback.

When the driver TX resync fails, kernel can retry the resync again
until it succeeds.  This prevents drivers from attempting to offload
TLS packets if the connection is known to be out of sync.

We don't worry about the RX resync since they will be retried naturally
as more encrypted records get received.

Signed-off-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-08 20:21:09 -07:00
David S. Miller af144a9834 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Two cases of overlapping changes, nothing fancy.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-08 19:48:57 -07:00
Jakub Kicinski 13aecb17ac net/tls: fix poll ignoring partially copied records
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>
2019-07-07 14:11:44 -07:00
Jakub Kicinski acd3e96d53 net/tls: make sure offload also gets the keys wiped
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>
2019-07-01 19:22:36 -07:00
Jakub Kicinski 618bac4593 net/tls: reject offload of TLS 1.3
Neither drivers nor the tls offload code currently supports TLS
version 1.3. Check the TLS version when installing connection
state. TLS 1.3 will just fallback to the kernel crypto for now.

Fixes: 130b392c6c ("net: tls: Add tls 1.3 support")
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>
2019-07-01 19:21:31 -07:00
David S. Miller d96ff269a0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
The new route handling in ip_mc_finish_output() from 'net' overlapped
with the new support for returning congestion notifications from BPF
programs.

In order to handle this I had to take the dev_loopback_xmit() calls
out of the switch statement.

The aquantia driver conflicts were simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-27 21:06:39 -07:00
Dirk van der Merwe 9354544cbc net/tls: fix page double free on TX cleanup
With commit 94850257cf ("tls: Fix tls_device handling of partial records")
a new path was introduced to cleanup partial records during sk_proto_close.
This path does not handle the SW KTLS tx_list cleanup.

This is unnecessary though since the free_resources calls for both
SW and offload paths will cleanup a partial record.

The visible effect is the following warning, but this bug also causes
a page double free.

    WARNING: CPU: 7 PID: 4000 at net/core/stream.c:206 sk_stream_kill_queues+0x103/0x110
    RIP: 0010:sk_stream_kill_queues+0x103/0x110
    RSP: 0018:ffffb6df87e07bd0 EFLAGS: 00010206
    RAX: 0000000000000000 RBX: ffff8c21db4971c0 RCX: 0000000000000007
    RDX: ffffffffffffffa0 RSI: 000000000000001d RDI: ffff8c21db497270
    RBP: ffff8c21db497270 R08: ffff8c29f4748600 R09: 000000010020001a
    R10: ffffb6df87e07aa0 R11: ffffffff9a445600 R12: 0000000000000007
    R13: 0000000000000000 R14: ffff8c21f03f2900 R15: ffff8c21f03b8df0
    Call Trace:
     inet_csk_destroy_sock+0x55/0x100
     tcp_close+0x25d/0x400
     ? tcp_check_oom+0x120/0x120
     tls_sk_proto_close+0x127/0x1c0
     inet_release+0x3c/0x60
     __sock_release+0x3d/0xb0
     sock_close+0x11/0x20
     __fput+0xd8/0x210
     task_work_run+0x84/0xa0
     do_exit+0x2dc/0xb90
     ? release_sock+0x43/0x90
     do_group_exit+0x3a/0xa0
     get_signal+0x295/0x720
     do_signal+0x36/0x610
     ? SYSC_recvfrom+0x11d/0x130
     exit_to_usermode_loop+0x69/0xb0
     do_syscall_64+0x173/0x180
     entry_SYSCALL_64_after_hwframe+0x3d/0xa2
    RIP: 0033:0x7fe9b9abc10d
    RSP: 002b:00007fe9b19a1d48 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
    RAX: fffffffffffffe00 RBX: 0000000000000006 RCX: 00007fe9b9abc10d
    RDX: 0000000000000002 RSI: 0000000000000080 RDI: 00007fe948003430
    RBP: 00007fe948003410 R08: 00007fe948003430 R09: 0000000000000000
    R10: 0000000000000000 R11: 0000000000000246 R12: 00005603739d9080
    R13: 00007fe9b9ab9f90 R14: 00007fe948003430 R15: 0000000000000000

Fixes: 94850257cf ("tls: Fix tls_device handling of partial records")
Signed-off-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-24 07:20:45 -07:00
David S. Miller 13091aa305 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Honestly all the conflicts were simple overlapping changes,
nothing really interesting to report.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-17 20:20:36 -07:00
John Fastabend 648ee6cea7 net: tls, correctly account for copied bytes with multiple sk_msgs
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>
2019-06-12 11:04:35 -07:00
Jakub Kicinski 5018007409 net/tls: add kernel-driven resync mechanism for TX
TLS offload drivers keep track of TCP seq numbers to make sure
the packets are fed into the HW in order.

When packets get dropped on the way through the stack, the driver
will get out of sync and have to use fallback encryption, but unless
TCP seq number is resynced it will never match the packets correctly
(or even worse - use incorrect record sequence number after TCP seq
wraps).

Existing drivers (mlx5) feed the entire record on every out-of-order
event, allowing FW/HW to always be in sync.

This patch adds an alternative, more akin to the RX resync.  When
driver sees a frame which is past its expected sequence number the
stream must have gotten out of order (if the sequence number is
smaller than expected its likely a retransmission which doesn't
require resync).  Driver will ask the stack to perform TX sync
before it submits the next full record, and fall back to software
crypto until stack has performed the sync.

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>
2019-06-11 12:22:27 -07:00
Jakub Kicinski eeb2efaf36 net/tls: generalize the resync callback
Currently only RX direction is ever resynced, however, TX may
also get out of sequence if packets get dropped on the way to
the driver.  Rename the resync callback and add a direction
parameter.

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>
2019-06-11 12:22:27 -07:00
Jakub Kicinski f953d33ba1 net/tls: add kernel-driven TLS RX resync
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>
2019-06-11 12:22:26 -07:00
Jakub Kicinski fe58a5a02c net/tls: rename handle_device_resync()
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>
2019-06-11 12:22:26 -07:00
Jakub Kicinski 89fec474fa net/tls: pass record number as a byte array
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>
2019-06-11 12:22:26 -07:00
Jakub Kicinski 4967373959 net/tls: simplify seq calculation in handle_device_resync()
We subtract "TLS_HEADER_SIZE - 1" from req_seq, then if they
match we add the same constant to seq.  Just add it to seq,
and we don't have to touch req_seq.

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>
2019-06-11 12:22:26 -07:00
David S. Miller a6cdeeb16b Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Some ISDN files that got removed in net-next had some changes
done in mainline, take the removals.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-07 11:00:14 -07:00
Dirk van der Merwe b9727d7f95 net/tls: export TLS per skb encryption
While offloading TLS connections, drivers need to handle the case where
out of order packets need to be transmitted.

Other drivers obtain the entire TLS record for the specific skb to
provide as context to hardware for encryption. However, other designs
may also want to keep the hardware state intact and perform the
out of order encryption entirely on the host.

To achieve this, export the already existing software encryption
fallback path so drivers could access this.

Signed-off-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-06 14:13:40 -07:00
Jakub Kicinski fb0f886fa2 net/tls: don't pass version to tls_advance_record_sn()
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>
2019-06-04 14:33:50 -07:00
Jakub Kicinski 9cd81988cc net/tls: use version from prot
ctx->prot holds the same information as per-direction contexts.
Almost all code gets TLS version from this structure, convert
the last two stragglers, this way we can improve the cache
utilization by moving the per-direction data into cold cache lines.

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>
2019-06-04 14:33:50 -07:00
Jakub Kicinski 1fe275d434 net/tls: don't re-check msg decrypted status in tls_device_decrypted()
tls_device_decrypted() is only called from decrypt_skb_update(),
when ctx->decrypted == false, there is no need to re-check the bit.

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>
2019-06-04 14:33:50 -07:00
Jakub Kicinski b9d8fec927 net/tls: don't look for decrypted frames on non-offloaded sockets
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>
2019-06-04 14:33:50 -07:00
Jakub Kicinski 87b11e0638 net/tls: remove false positive warning
It's possible that TCP stack will decide to retransmit a packet
right when that packet's data gets acked, especially in presence
of packet reordering.  This means that packets may be in flight,
even though tls_device code has already freed their record state.
Make fill_sg_in() and in turn tls_sw_fallback() not generate a
warning in that case, and quietly proceed to drop such frames.

Make the exit path from tls_sw_fallback() drop monitor friendly,
for users to be able to troubleshoot dropped retransmissions.

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>
2019-06-04 14:33:50 -07:00
Jakub Kicinski aeb11ff0dc net/tls: check return values from skb_copy_bits() and skb_store_bits()
In light of recent bugs, we should make a better effort of
checking return values.  In theory none of the functions should
fail today.

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>
2019-06-04 14:33:50 -07:00
Jakub Kicinski e52972c11d net/tls: replace the sleeping lock around RX resync with a bit lock
Commit 38030d7cb7 ("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>
2019-06-04 13:34:37 -07:00
Jakub Kicinski 27393f8c6e Revert "net/tls: avoid NULL-deref on resync during device removal"
This reverts commit 38030d7cb7.
Unfortunately the RX resync may get called from soft IRQ,
so we can't take the rwsem to protect from the device
disappearing.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-04 13:34:37 -07:00
Jakub Kicinski 04b25a5411 net/tls: fix no wakeup on partial reads
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>
2019-05-26 21:47:13 -07:00
Jakub Kicinski 46a1695960 net/tls: fix lowat calculation if some data came from previous record
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>
2019-05-26 21:47:12 -07:00
Jakub Kicinski c3f4a6c39c net/tls: don't ignore netdev notifications if no TLS features
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>
2019-05-22 12:21:44 -07:00
Jakub Kicinski 3686637e50 net/tls: fix state removal with feature flags off
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>
2019-05-22 12:21:44 -07:00
Jakub Kicinski 38030d7cb7 net/tls: avoid NULL-deref on resync during device removal
When netdev with active kTLS sockets in unregistered
notifier callback walks the offloaded sockets and
cleans up offload state.  RX data may still be processed,
however, and if resync was requested prior to device
removal we would hit a NULL pointer dereference on
ctx->netdev use.

Make sure resync is under the device offload lock
and NULL-check the netdev pointer.

This should be safe, because the pointer is set to
NULL either in the netdev notifier (under said lock)
or when socket is completely dead and no resync can
happen.

The other access to ctx->netdev in tls_validate_xmit_skb()
does not dereference the pointer, it just checks it against
other device pointer, so it should be pretty safe (perhaps
we can add a READ_ONCE/WRITE_ONCE there, if paranoid).

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>
2019-05-22 12:21:44 -07:00
Thomas Gleixner ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:46 +02:00
Jakub Kicinski b53f4976fb net/tls: handle errors from padding_length()
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>
2019-05-09 16:37:39 -07:00
Jakub Kicinski 88c80bee88 net/tls: remove set but not used variables
Commit 4504ab0e6e ("net/tls: Inform user space about send buffer availability")
made us report write_space regardless whether partial record
push was successful or not.  Remove the now unused return value
to clean up the following W=1 warning:

net/tls/tls_device.c: In function ‘tls_device_write_space’:
net/tls/tls_device.c:546:6: warning: variable ‘rc’ set but not used [-Wunused-but-set-variable]
  int rc = 0;
      ^~

CC: Vakul Garg <vakul.garg@nxp.com>
CC: Boris Pismenny <borisp@mellanox.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>
2019-05-09 16:37:39 -07:00
Jakub Kicinski 494bc1d281 net/tcp: use deferred jump label for TCP acked data hook
User space can flip the clean_acked_data_enabled static branch
on and off with TLS offload when CONFIG_TLS_DEVICE is enabled.
jump_label.h suggests we use the delayed version in this case.

Deferred branches now also don't take the branch mutex on
decrement, so we avoid potential locking issues.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-09 11:13:57 -07:00
David S. Miller ff24e4980a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Three trivial overlapping conflicts.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-02 22:14:21 -04:00
Jakub Kicinski 2dcb003314 net/tls: avoid NULL pointer deref on nskb->sk in fallback
update_chksum() accesses nskb->sk before it has been set
by complete_skb(), move the init up.

Fixes: e8f6979981 ("net/tls: Add generic NIC offload infrastructure")
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>
2019-05-01 11:37:56 -04:00
Jakub Kicinski eb3d38d5ad net/tls: fix copy to fragments in reencrypt
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>
2019-04-27 20:17:19 -04:00
Jakub Kicinski 97e1caa517 net/tls: don't copy negative amounts of data in reencrypt
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>
2019-04-27 20:17:19 -04:00