14 Commits

Author SHA1 Message Date
Jakub Kicinski
d615070b0e tls: improve lockless access safety of tls_err_abort()
[ Upstream commit 8a0d57df8938e9fd2e99d47a85b7f37d86f91097 ]

Most protos' poll() methods insert a memory barrier between
writes to sk_err and sk_error_report(). This dates back to
commit a4d258036ed9 ("tcp: Fix race in tcp_poll").

I guess we should do the same thing in TLS, tcp_poll() does
not hold the socket lock.

Fixes: 3c4d7559159b ("tls: kernel TLS support")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-09 10:34:01 +02:00
Jakub Kicinski
3347ac7a81 tls: rx: strp: preserve decryption status of skbs when needed
[ Upstream commit eca9bfafee3a0487e59c59201ae14c7594ba940a ]

When receive buffer is small we try to copy out the data from
TCP into a skb maintained by TLS to prevent connection from
stalling. Unfortunately if a single record is made up of a mix
of decrypted and non-decrypted skbs combining them into a single
skb leads to loss of decryption status, resulting in decryption
errors or data corruption.

Similarly when trying to use TCP receive queue directly we need
to make sure that all the skbs within the record have the same
status. If we don't the mixed status will be detected correctly
but we'll CoW the anchor, again collapsing it into a single paged
skb without decrypted status preserved. So the "fixup" code will
not know which parts of skb to re-encrypt.

Fixes: 84c61fe1a75b ("tls: rx: do not use the standard strparser")
Tested-by: Shai Amiram <samiram@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-05 09:26:18 +02:00
Jakub Kicinski
ba93977437 tls: rx: strp: factor out copying skb data
[ Upstream commit c1c607b1e5d5477d82ca6a86a05a4f10907b33ee ]

We'll need to copy input skbs individually in the next patch.
Factor that code out (without assuming we're copying a full record).

Tested-by: Shai Amiram <samiram@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: eca9bfafee3a ("tls: rx: strp: preserve decryption status of skbs when needed")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-05 09:26:18 +02:00
Jakub Kicinski
52a89de3e9 tls: rx: strp: force mixed decrypted records into copy mode
[ Upstream commit 14c4be92ebb3e36e392aa9dd8f314038a9f96f3c ]

If a record is partially decrypted we'll have to CoW it, anyway,
so go into copy mode and allocate a writable skb right away.

This will make subsequent fix simpler because we won't have to
teach tls_strp_msg_make_copy() how to copy skbs while preserving
decrypt status.

Tested-by: Shai Amiram <samiram@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: eca9bfafee3a ("tls: rx: strp: preserve decryption status of skbs when needed")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-05 09:26:17 +02:00
Jakub Kicinski
c48b8399e4 tls: rx: strp: fix determining record length in copy mode
[ Upstream commit 8b0c0dc9fbbd01e58a573a41c38885f9e4c17696 ]

We call tls_rx_msg_size(skb) before doing skb->len += chunk.
So the tls_rx_msg_size() code will see old skb->len, most
likely leading to an over-read.

Worst case we will over read an entire record, next iteration
will try to trim the skb but may end up turning frag len negative
or discarding the subsequent record (since we already told TCP
we've read it during previous read but now we'll trim it out of
the skb).

Fixes: 84c61fe1a75b ("tls: rx: do not use the standard strparser")
Tested-by: Shai Amiram <samiram@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-05 09:26:17 +02:00
Jakub Kicinski
ecd9f6ed9e tls: rx: strp: set the skb->len of detached / CoW'ed skbs
[ Upstream commit 210620ae44a83f25220450bbfcc22e6fe986b25f ]

alloc_skb_with_frags() fills in page frag sizes but does not
set skb->len and skb->data_len. Set those correctly otherwise
device offload will most likely generate an empty skb and
hit the BUG() at the end of __skb_nsg().

Fixes: 84c61fe1a75b ("tls: rx: do not use the standard strparser")
Tested-by: Shai Amiram <samiram@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-06-05 09:26:17 +02:00
Jakub Kicinski
0d87bbd39d tls: strp: make sure the TCP skbs do not have overlapping data
TLS tries to get away with using the TCP input queue directly.
This does not work if there is duplicated data (multiple skbs
holding bytes for the same seq number range due to retransmits).
Check for this condition and fall back to copy mode, it should
be rare.

Fixes: 84c61fe1a75b ("tls: rx: do not use the standard strparser")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-10-14 08:25:26 +01:00
Jakub Kicinski
d800a7b357 tls: rx: device: don't try to copy too much on detach
Another device offload bug, we use the length of the output
skb as an indication of how much data to copy. But that skb
is sized to offset + record length, and we start from offset.
So we end up double-counting the offset which leads to
skb_copy_bits() returning -EFAULT.

Reported-by: Tariq Toukan <tariqt@nvidia.com>
Fixes: 84c61fe1a75b ("tls: rx: do not use the standard strparser")
Tested-by: Ran Rozenstein <ranro@nvidia.com>
Link: https://lore.kernel.org/r/20220809175544.354343-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-08-10 22:53:25 -07:00
Yang Li
8fd1e15177 tls: rx: Fix unsigned comparison with less than zero
The return from the call to tls_rx_msg_size() is int, it can be
a negative error code, however this is being assigned to an
unsigned long variable 'sz', so making 'sz' an int.

Eliminate the following coccicheck warning:
./net/tls/tls_strp.c:211:6-8: WARNING: Unsigned expression compared with zero: sz < 0

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220728031019.32838-1-yang.lee@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-28 21:50:39 -07:00
Jakub Kicinski
d11ef9cc5a tls: strp: rename and multithread the workqueue
Paolo points out that there seems to be no strong reason strparser
users a single threaded workqueue. Perhaps there were some performance
or pinning considerations? Since we don't know (and it's the slow path)
let's default to the most natural, multi-threaded choice.

Also rename the workqueue to "tls-".

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-28 21:49:59 -07:00
Jakub Kicinski
84c61fe1a7 tls: rx: do not use the standard strparser
TLS is a relatively poor fit for strparser. We pause the input
every time a message is received, wait for a read which will
decrypt the message, start the parser, repeat. strparser is
built to delineate the messages, wrap them in individual skbs
and let them float off into the stack or a different socket.
TLS wants the data pages and nothing else. There's no need
for TLS to keep cloning (and occasionally skb_unclone()'ing)
the TCP rx queue.

This patch uses a pre-allocated skb and attaches the skbs
from the TCP rx queue to it as frags. TLS is careful never
to modify the input skb without CoW'ing / detaching it first.

Since we call TCP rx queue cleanup directly we also get back
the benefit of skb deferred free.

Overall this results in a 6% gain in my benchmarks.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-26 14:38:51 -07:00
Jakub Kicinski
8b3c59a7a0 tls: rx: device: add input CoW helper
Wrap the remaining skb_cow_data() into a helper, so it's easier
to replace down the lane. The new version will change the skb
so make sure relevant pointers get reloaded after the call.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-26 14:38:51 -07:00
Jakub Kicinski
d4e5db6452 tls: rx: device: keep the zero copy status with offload
The non-zero-copy path assumes a full skb with decrypted contents.
This means the device offload would have to CoW the data. Try
to keep the zero-copy status instead, copy the data to user space.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-26 14:38:51 -07:00
Jakub Kicinski
c618db2afe tls: rx: async: hold onto the input skb
Async crypto currently benefits from the fact that we decrypt
in place. When we allow input and output to be different skbs
we will have to hang onto the input while we move to the next
record. Clone the inputs and keep them on a list.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18 11:24:11 +01:00