linux-stable.git/net/tls, branch v5.10.78

net/tls: Fix flipped sign in async_wait.err assignment

2021-11-02T18:48:23+00:00

commit 1d9d6fd21ad4a28b16ed9ee5432ae738b9dc58aa upstream.

sk->sk_err contains a positive number, yet async_wait.err wants the
opposite.  Fix the missed sign flip, which Jakub caught by inspection.

Fixes: a42055e8d2c3 ("net/tls: Add support for async encryption of records for performance")
Suggested-by: Jakub Kicinski 
Signed-off-by: Daniel Jordan 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net/tls: Fix flipped sign in tls_err_abort() calls

2021-11-02T18:48:19+00:00

commit da353fac65fede6b8b4cfe207f0d9408e3121105 upstream.

sk->sk_err appears to expect a positive value, a convention that ktls
doesn't always follow and that leads to memory corruption in other code.
For instance,

    [kworker]
    tls_encrypt_done(..., err=)
      tls_err_abort(.., err)
        sk->sk_err = err;

    [task]
    splice_from_pipe_feed
      ...
        tls_sw_do_sendpage
          if (sk->sk_err) {
            ret = -sk->sk_err;  // ret is positive

    splice_from_pipe_feed (continued)
      ret = actor(...)  // ret is still positive and interpreted as bytes
                        // written, resulting in underflow of buf->len and
                        // sd->len, leading to huge buf->offset and bogus
                        // addresses computed in later calls to actor()

Fix all tls_err_abort() callers to pass a negative error code
consistently and centralize the error-prone sign flip there, throwing in
a warning to catch future misuse and uninlining the function so it
really does only warn once.

Cc: stable@vger.kernel.org
Fixes: c46234ebb4d1e ("tls: RX path for ktls")
Reported-by: syzbot+b187b77c8474f9648fae@syzkaller.appspotmail.com
Signed-off-by: Daniel Jordan 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tls: prevent oversized sendfile() hangs by ignoring MSG_MORE

2021-07-14T14:56:24+00:00

[ Upstream commit d452d48b9f8b1a7f8152d33ef52cfd7fe1735b0a ]

We got multiple reports that multi_chunk_sendfile test
case from tls selftest fails. This was sort of expected,
as the original fix was never applied (see it in the first
Link:). The test in question uses sendfile() with count
larger than the size of the underlying file. This will
make splice set MSG_MORE on all sendpage calls, meaning
TLS will never close and flush the last partial record.

Eric seem to have addressed a similar problem in
commit 35f9c09fe9c7 ("tcp: tcp_sendpages() should call tcp_push() once")
by introducing MSG_SENDPAGE_NOTLAST. Unlike MSG_MORE
MSG_SENDPAGE_NOTLAST is not set on the last call
of a "pipefull" of data (PIPE_DEF_BUFFERS == 16,
so every 16 pages or whenever we run out of data).

Having a break every 16 pages should be fine, TLS
can pack exactly 4 pages into a record, so for
aligned reads there should be no difference,
unaligned may see one extra record per sendpage().

Sticking to TCP semantics seems preferable to modifying
splice, but we can revisit it if real life scenarios
show a regression.

Reported-by: Vadim Fedorenko 
Reported-by: Seth Forshee 
Link: https://lore.kernel.org/netdev/1591392508-14592-1-git-send-email-pooja.trivedi@stackpath.com/
Fixes: 3c4d7559159b ("tls: kernel TLS support")
Signed-off-by: Jakub Kicinski 
Tested-by: Seth Forshee 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net/tls: Fix use-after-free after the TLS device goes down and up

2021-06-10T11:39:18+00:00

[ Upstream commit c55dcdd435aa6c6ad6ccac0a4c636d010ee367a4 ]

When a netdev with active TLS offload goes down, tls_device_down is
called to stop the offload and tear down the TLS context. However, the
socket stays alive, and it still points to the TLS context, which is now
deallocated. If a netdev goes up, while the connection is still active,
and the data flow resumes after a number of TCP retransmissions, it will
lead to a use-after-free of the TLS context.

This commit addresses this bug by keeping the context alive until its
normal destruction, and implements the necessary fallbacks, so that the
connection can resume in software (non-offloaded) kTLS mode.

On the TX side tls_sw_fallback is used to encrypt all packets. The RX
side already has all the necessary fallbacks, because receiving
non-decrypted packets is supported. The thing needed on the RX side is
to block resync requests, which are normally produced after receiving
non-decrypted packets.

The necessary synchronization is implemented for a graceful teardown:
first the fallbacks are deployed, then the driver resources are released
(it used to be possible to have a tls_dev_resync after tls_dev_del).

A new flag called TLS_RX_DEV_DEGRADED is added to indicate the fallback
mode. It's used to skip the RX resync logic completely, as it becomes
useless, and some objects may be released (for example, resync_async,
which is allocated and freed by the driver).

Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Maxim Mikityanskiy 
Reviewed-by: Tariq Toukan 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net/tls: Replace TLS_RX_SYNC_RUNNING with RCU

2021-06-10T11:39:17+00:00

[ Upstream commit 05fc8b6cbd4f979a6f25759c4a17dd5f657f7ecd ]

RCU synchronization is guaranteed to finish in finite time, unlike a
busy loop that polls a flag. This patch is a preparation for the bugfix
in the next patch, where the same synchronize_net() call will also be
used to sync with the TX datapath.

Signed-off-by: Maxim Mikityanskiy 
Reviewed-by: Tariq Toukan 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

tls splice: check SPLICE_F_NONBLOCK instead of MSG_DONTWAIT

2021-06-03T07:00:47+00:00

[ Upstream commit 974271e5ed45cfe4daddbeb16224a2156918530e ]

In tls_sw_splice_read, checkout MSG_* is inappropriate, should use
SPLICE_*, update tls_wait_data to accept nonblock arguments instead
of flags for recvmsg and splice.

Fixes: c46234ebb4d1 ("tls: RX path for ktls")
Signed-off-by: Jim Ma 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: fix proc_fs init handling in af_packet and tls

2021-02-23T14:53:23+00:00

[ Upstream commit a268e0f2455c32653140775662b40c2b1f1b2efa ]

proc_fs was used, in af_packet, without a surrounding #ifdef,
although there is no hard dependency on proc_fs.
That caused the initialization of the af_packet module to fail
when CONFIG_PROC_FS=n.

Specifically, proc_create_net() was used in af_packet.c,
and when it fails, packet_net_init() returns -ENOMEM.
It will always fail when the kernel is compiled without proc_fs,
because, proc_create_net() for example always returns NULL.

The calling order that starts in af_packet.c is as follows:
packet_init()
register_pernet_subsys()
register_pernet_operations()
__register_pernet_operations()
ops_init()
ops->init() (packet_net_ops.init=packet_net_init())
proc_create_net()

It worked in the past because register_pernet_subsys()'s return value
wasn't checked before this Commit 36096f2f4fa0 ("packet: Fix error path in
packet_init.").
It always returned an error, but was not checked before, so everything
was working even when CONFIG_PROC_FS=n.

The fix here is simply to add the necessary #ifdef.

This also fixes a similar error in tls_proc.c, that was found by Jakub
Kicinski.

Fixes: d26b698dd3cd ("net/tls: add skeleton of MIB statistics")
Fixes: 36096f2f4fa0 ("packet: Fix error path in packet_init")
Signed-off-by: Yonatan Linik 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net/tls: Protect from calling tls_dev_del for TLS RX twice

2020-11-26T01:31:06+00:00

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

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

Fixes: e8f69799810c ("net/tls: Add generic NIC offload infrastructure")
Signed-off-by: Maxim Mikityanskiy 
Signed-off-by: Saeed Mahameed 
Link: https://lore.kernel.org/r/20201125221810.69870-1-saeedm@nvidia.com
Signed-off-by: Jakub Kicinski

net/tls: missing received data after fast remote close

2020-11-20T18:25:26+00:00

In case when tcp socket received FIN after some data and the
parser haven't started before reading data caller will receive
an empty buffer. This behavior differs from plain TCP socket and
leads to special treating in user-space.
The flow that triggers the race is simple. Server sends small
amount of data right after the connection is configured to use TLS
and closes the connection. In this case receiver sees TLS Handshake
data, configures TLS socket right after Change Cipher Spec record.
While the configuration is in process, TCP socket receives small
Application Data record, Encrypted Alert record and FIN packet. So
the TCP socket changes sk_shutdown to RCV_SHUTDOWN and sk_flag with
SK_DONE bit set. The received data is not parsed upon arrival and is
never sent to user-space.

Patch unpauses parser directly if we have unparsed data in tcp
receive queue.

Fixes: fcf4793e278e ("tls: check RCV_SHUTDOWN in tls_wait_data")
Signed-off-by: Vadim Fedorenko 
Link: https://lore.kernel.org/r/1605801588-12236-1-git-send-email-vfedorenko@novek.ru
Signed-off-by: Jakub Kicinski

net/tls: Fix wrong record sn in async mode of device resync

2020-11-17T22:41:20+00:00

In async_resync mode, we log the TCP seq of records until the async request
is completed.  Later, in case one of the logged seqs matches the resync
request, we return it, together with its record serial number.  Before this
fix, we mistakenly returned the serial number of the current record
instead.

Fixes: ed9b7646b06a ("net/tls: Add asynchronous resync")
Signed-off-by: Tariq Toukan 
Reviewed-by: Boris Pismenny 
Link: https://lore.kernel.org/r/20201115131448.2702-1-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski