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[ Upstream commit 70f360dd7042cb843635ece9d28335a4addff9eb ]
This field can be read locklessly.
Fixes: 1536e2857bd3 ("tcp: Add a TCP_FASTOPEN socket option to get a max backlog on its listner")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230719212857.3943972-12-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f0628c524fd188c3f9418e12478dfdfadacba815 ]
This patch changes the behavior of TCP_LINGER2 about its limit. The
sysctl_tcp_fin_timeout used to be the limit of TCP_LINGER2 but now it's
only the default value. A new macro named TCP_FIN_TIMEOUT_MAX is added
as the limit of TCP_LINGER2, which is 2 minutes.
Since TCP_LINGER2 used sysctl_tcp_fin_timeout as the default value
and the limit in the past, the system administrator cannot set the
default value for most of sockets and let some sockets have a greater
timeout. It might be a mistake that let the sysctl to be the limit of
the TCP_LINGER2. Maybe we can add a new sysctl to set the max of
TCP_LINGER2, but FIN-WAIT-2 timeout is usually no need to be too long
and 2 minutes are legal considering TCP specs.
Changes in v3:
- Remove the new socket option and change the TCP_LINGER2 behavior so
that the timeout can be set to value between sysctl_tcp_fin_timeout
and 2 minutes.
Changes in v2:
- Add int overflow check for the new socket option.
Changes in v1:
- Add a new socket option to set timeout greater than
sysctl_tcp_fin_timeout.
Signed-off-by: Cambda Zhu <cambda@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 9df5335ca974 ("tcp: annotate data-races around tp->linger2")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 34dfde4ad87b84d21278a7e19d92b5b2c68e6c4d ]
This patch replaces the tp->mss_cache check in getting TCP_MAXSEG
with tp->rx_opt.user_mss check for CLOSE/LISTEN sock. Since
tp->mss_cache is initialized with TCP_MSS_DEFAULT, checking if
it's zero is probably a bug.
With this change, getting TCP_MAXSEG before connecting will return
default MSS normally, and return user_mss if user_mss is set.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Jack Yang <mingliang@linux.alibaba.com>
Suggested-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/netdev/CANn89i+3kL9pYtkxkwxwNMzvC_w3LNUum_2=3u+UyLBmGmifHA@mail.gmail.com/#t
Signed-off-by: Cambda Zhu <cambda@linux.alibaba.com>
Link: https://lore.kernel.org/netdev/14D45862-36EA-4076-974C-EA67513C92F6@linux.alibaba.com/
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230527040317.68247-1-cambda@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 300b655db1b5152d6101bcb6801d50899b20c2d6 ]
The initial default value of 0 for tp->rate_app_limited was incorrect,
since a flow is indeed application-limited until it first sends
data. Fixing the default to be 1 is generally correct but also
specifically will help user-space applications avoid using the initial
tcpi_delivery_rate value of 0 that persists until the connection has
some non-zero bandwidth sample.
Fixes: eb8329e0a04d ("tcp: export data delivery rate")
Suggested-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David Morley <morleyd@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Tested-by: David Morley <morleyd@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit aacd467c0a576e5e44d2de4205855dc0fe43f6fb ]
tcp_md5sig_pool_populated can be read while another thread
changes its value.
The race has no consequence because allocations
are protected with tcp_md5sig_mutex.
This patch adds READ_ONCE() and WRITE_ONCE() to document
the race and silence KCSAN.
Reported-by: Abhishek Shah <abhishek.shah@columbia.edu>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f4ce91ce12a7c6ead19b128ffa8cff6e3ded2a14 ]
This commit fixes a bug in the tracking of max_packets_out and
is_cwnd_limited. This bug can cause the connection to fail to remember
that is_cwnd_limited is true, causing the connection to fail to grow
cwnd when it should, causing throughput to be lower than it should be.
The following event sequence is an example that triggers the bug:
(a) The connection is cwnd_limited, but packets_out is not at its
peak due to TSO deferral deciding not to send another skb yet.
In such cases the connection can advance max_packets_seq and set
tp->is_cwnd_limited to true and max_packets_out to a small
number.
(b) Then later in the round trip the connection is pacing-limited (not
cwnd-limited), and packets_out is larger. In such cases the
connection would raise max_packets_out to a bigger number but
(unexpectedly) flip tp->is_cwnd_limited from true to false.
This commit fixes that bug.
One straightforward fix would be to separately track (a) the next
window after max_packets_out reaches a maximum, and (b) the next
window after tp->is_cwnd_limited is set to true. But this would
require consuming an extra u32 sequence number.
Instead, to save space we track only the most important
information. Specifically, we track the strongest available signal of
the degree to which the cwnd is fully utilized:
(1) If the connection is cwnd-limited then we remember that fact for
the current window.
(2) If the connection not cwnd-limited then we track the maximum
number of outstanding packets in the current window.
In particular, note that the new logic cannot trigger the buggy
(a)/(b) sequence above because with the new logic a condition where
tp->packets_out > tp->max_packets_out can only trigger an update of
tp->is_cwnd_limited if tp->is_cwnd_limited is false.
This first showed up in a testing of a BBRv2 dev branch, but this
buggy behavior highlighted a general issue with the
tcp_cwnd_validate() logic that can cause cwnd to fail to increase at
the proper rate for any TCP congestion control, including Reno or
CUBIC.
Fixes: ca8a22634381 ("tcp: make cwnd-limited checks measurement-based, and gentler")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Kevin(Yudong) Yang <yyd@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 85225e6f0a76e6745bc841c9f25169c509b573d8 ]
While reading sysctl_tcp_autocorking, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.
Fixes: f54b311142a9 ("tcp: auto corking")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5a54213318c43f4009ae158347aa6016e3b9b55a ]
While reading sysctl_tcp_fastopen, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.
Fixes: 2100c8d2d9db ("net-tcp: Fast Open base")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 39e24435a776e9de5c6dd188836cf2523547804b ]
While reading these sysctl knobs, they can be changed concurrently.
Thus, we need to add READ_ONCE() to their readers.
- tcp_retries1
- tcp_retries2
- tcp_orphan_retries
- tcp_fin_timeout
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 46778cd16e6a5ad1b2e3a91f6c057c907379418e ]
While reading sysctl_tcp_reordering, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e3d5ea2c011ecb16fb94c56a659364e6b30fac94 ]
If recv_actor() returns an incorrect value, tcp_read_sock()
might loop forever.
Instead, issue a one time warning and make sure to make progress.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20220302161723.3910001-2-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cf12e6f9124629b18a6182deefc0315f0a73a199 ]
v1: Implement a more general statement as recommended by Eric Dumazet. The
sequence number will be advanced, so this check will fix the FIN case and
other cases.
A customer reported sockets stuck in the CLOSING state. A Vmcore revealed that
the write_queue was not empty as determined by tcp_write_queue_empty() but the
sk_buff containing the FIN flag had been freed and the socket was zombied in
that state. Corresponding pcaps show no FIN from the Linux kernel on the wire.
Some instrumentation was added to the kernel and it was found that there is a
timing window where tcp_sendmsg() can run after tcp_send_fin().
tcp_sendmsg() will hit an error, for example:
1269 ▹ if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))↩
1270 ▹ ▹ goto do_error;↩
tcp_remove_empty_skb() will then free the FIN sk_buff as "skb->len == 0". The
TCP socket is now wedged in the FIN-WAIT-1 state because the FIN is never sent.
If the other side sends a FIN packet the socket will transition to CLOSING and
remain that way until the system is rebooted.
Fix this by checking for the FIN flag in the sk_buff and don't free it if that
is the case. Testing confirmed that fixed the issue.
Fixes: fdfc5c8594c2 ("tcp: remove empty skb from write queue in error cases")
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Reported-by: Monir Zouaoui <Monir.Zouaoui@mail.schwarz>
Reported-by: Simon Stier <simon.stier@mail.schwarz>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 9d9b1ee0b2d1c9e02b2338c4a4b0a062d2d3edac upstream.
The TCP session does not terminate with TCP_USER_TIMEOUT when data
remain untransmitted due to zero window.
The number of unanswered zero-window probes (tcp_probes_out) is
reset to zero with incoming acks irrespective of the window size,
as described in tcp_probe_timer():
RFC 1122 4.2.2.17 requires the sender to stay open indefinitely
as long as the receiver continues to respond probes. We support
this by default and reset icsk_probes_out with incoming ACKs.
This counter, however, is the wrong one to be used in calculating the
duration that the window remains closed and data remain untransmitted.
Thanks to Jonathan Maxwell <jmaxwell37@gmail.com> for diagnosing the
actual issue.
In this patch a new timestamp is introduced for the socket in order to
track the elapsed time for the zero-window probes that have not been
answered with any non-zero window ack.
Fixes: 9721e709fa68 ("tcp: simplify window probe aborting on USER_TIMEOUT")
Reported-by: William McCall <william.mccall@gmail.com>
Co-developed-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Enke Chen <enchen@paloaltonetworks.com>
Reviewed-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20210115223058.GA39267@localhost.localdomain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 435ccfa894e35e3d4a1799e6ac030e48a7b69ef5 ]
With SO_RCVLOWAT, under memory pressure,
it is possible to enter a state where:
1. We have not received enough bytes to satisfy SO_RCVLOWAT.
2. We have not entered buffer pressure (see tcp_rmem_pressure()).
3. But, we do not have enough buffer space to accept more packets.
In this case, we advertise 0 rwnd (due to #3) but the application does
not drain the receive queue (no wakeup because of #1 and #2) so the
flow stalls.
Modify the heuristic for SO_RCVLOWAT so that, if we are advertising
rwnd<=rcv_mss, force a wakeup to prevent a stall.
Without this patch, setting tcp_rmem to 6143 and disabling TCP
autotune causes a stalled flow. With this patch, no stall occurs. This
is with RPC-style traffic with large messages.
Fixes: 03f45c883c6f ("tcp: avoid extra wakeups for SO_RCVLOWAT users")
Signed-off-by: Arjun Roy <arjunroy@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20201023184709.217614-1-arjunroy.kdev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cf83a17edeeb36195596d2dae060a7c381db35f1 upstream.
commit a10674bf2406 ("tcp: detecting the misuse of .sendpage for Slab
objects") adds the checks for Slab pages, but the pages don't have
page_count are still missing from the check.
Network layer's sendpage method is not designed to send page_count 0
pages neither, therefore both PageSlab() and page_count() should be
both checked for the sending page. This is exactly what sendpage_ok()
does.
This patch uses sendpage_ok() in do_tcp_sendpages() to detect misused
.sendpage, to make the code more robust.
Fixes: a10674bf2406 ("tcp: detecting the misuse of .sendpage for Slab objects")
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Cc: Vasily Averin <vvs@virtuozzo.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: stable@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f19008e676366c44e9241af57f331b6c6edf9552 ]
When TFO keys are read back on big endian systems either via the global
sysctl interface or via getsockopt() using TCP_FASTOPEN_KEY, the values
don't match what was written.
For example, on s390x:
# echo "1-2-3-4" > /proc/sys/net/ipv4/tcp_fastopen_key
# cat /proc/sys/net/ipv4/tcp_fastopen_key
02000000-01000000-04000000-03000000
Instead of:
# cat /proc/sys/net/ipv4/tcp_fastopen_key
00000001-00000002-00000003-00000004
Fix this by converting to the correct endianness on read. This was
reported by Colin Ian King when running the 'tcp_fastopen_backup_key' net
selftest on s390x, which depends on the read value matching what was
written. I've confirmed that the test now passes on big and little endian
systems.
Signed-off-by: Jason Baron <jbaron@akamai.com>
Fixes: 438ac88009bc ("net: fastopen: robustness and endianness fixes for SipHash")
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Eric Dumazet <edumazet@google.com>
Reported-and-tested-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1ca0fafd73c5268e8fc4b997094b8bb2bfe8deea ]
This essentially reverts commit 721230326891 ("tcp: md5: reject TCP_MD5SIG
or TCP_MD5SIG_EXT on established sockets")
Mathieu reported that many vendors BGP implementations can
actually switch TCP MD5 on established flows.
Quoting Mathieu :
Here is a list of a few network vendors along with their behavior
with respect to TCP MD5:
- Cisco: Allows for password to be changed, but within the hold-down
timer (~180 seconds).
- Juniper: When password is initially set on active connection it will
reset, but after that any subsequent password changes no network
resets.
- Nokia: No notes on if they flap the tcp connection or not.
- Ericsson/RedBack: Allows for 2 password (old/new) to co-exist until
both sides are ok with new passwords.
- Meta-Switch: Expects the password to be set before a connection is
attempted, but no further info on whether they reset the TCP
connection on a change.
- Avaya: Disable the neighbor, then set password, then re-enable.
- Zebos: Would normally allow the change when socket connected.
We can revert my prior change because commit 9424e2e7ad93 ("tcp: md5: fix potential
overestimation of TCP option space") removed the leak of 4 kernel bytes to
the wire that was the main reason for my patch.
While doing my investigations, I found a bug when a MD5 key is changed, leading
to these commits that stable teams want to consider before backporting this revert :
Commit 6a2febec338d ("tcp: md5: add missing memory barriers in tcp_md5_do_add()/tcp_md5_hash_key()")
Commit e6ced831ef11 ("tcp: md5: refine tcp_md5_do_add()/tcp_md5_hash_key() barriers")
Fixes: 721230326891 "tcp: md5: reject TCP_MD5SIG or TCP_MD5SIG_EXT on established sockets"
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e6ced831ef11a2a06e8d00aad9d4fc05b610bf38 ]
My prior fix went a bit too far, according to Herbert and Mathieu.
Since we accept that concurrent TCP MD5 lookups might see inconsistent
keys, we can use READ_ONCE()/WRITE_ONCE() instead of smp_rmb()/smp_wmb()
Clearing all key->key[] is needed to avoid possible KMSAN reports,
if key->keylen is increased. Since tcp_md5_do_add() is not fast path,
using __GFP_ZERO to clear all struct tcp_md5sig_key is simpler.
data_race() was added in linux-5.8 and will prevent KCSAN reports,
this can safely be removed in stable backports, if data_race() is
not yet backported.
v2: use data_race() both in tcp_md5_hash_key() and tcp_md5_do_add()
Fixes: 6a2febec338d ("tcp: md5: add missing memory barriers in tcp_md5_do_add()/tcp_md5_hash_key()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Marco Elver <elver@google.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6a2febec338df7e7699a52d00b2e1207dcf65b28 ]
MD5 keys are read with RCU protection, and tcp_md5_do_add()
might update in-place a prior key.
Normally, typical RCU updates would allocate a new piece
of memory. In this case only key->key and key->keylen might
be updated, and we do not care if an incoming packet could
see the old key, the new one, or some intermediate value,
since changing the key on a live flow is known to be problematic
anyway.
We only want to make sure that in the case key->keylen
is changed, cpus in tcp_md5_hash_key() wont try to use
uninitialized data, or crash because key->keylen was
read twice to feed sg_init_one() and ahash_request_set_crypt()
Fixes: 9ea88a153001 ("tcp: md5: check md5 signature without socket lock")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit cc4de047b33be247f9c8150d3e496743a49642b8 ]
The stated intent of the original commit is to is to "return the timestamp
corresponding to the highest sequence number data returned." The current
implementation returns the timestamp for the last byte of the last fully
read skb, which is not necessarily the last byte in the recv buffer. This
patch converts behavior to the original definition, and to the behavior of
the previous draft versions of commit 98aaa913b4ed ("tcp: Extend
SOF_TIMESTAMPING_RX_SOFTWARE to TCP recvmsg") which also match this
behavior.
Fixes: 98aaa913b4ed ("tcp: Extend SOF_TIMESTAMPING_RX_SOFTWARE to TCP recvmsg")
Co-developed-by: Iris Liu <iris@onechronos.com>
Signed-off-by: Iris Liu <iris@onechronos.com>
Signed-off-by: Kelly Littlepage <kelly@onechronos.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 24adbc1676af4e134e709ddc7f34cf2adc2131e4 ]
We autotune rcvbuf whenever SO_RCVLOWAT is set to account for 100%
overhead in tcp_set_rcvlowat()
This works well when skb->len/skb->truesize ratio is bigger than 0.5
But if we receive packets with small MSS, we can end up in a situation
where not enough bytes are available in the receive queue to satisfy
RCVLOWAT setting.
As our sk_rcvbuf limit is hit, we send zero windows in ACK packets,
preventing remote peer from sending more data.
Even autotuning does not help, because it only triggers at the time
user process drains the queue. If no EPOLLIN is generated, this
can not happen.
Note poll() has a similar issue, after commit
c7004482e8dc ("tcp: Respect SO_RCVLOWAT in tcp_poll().")
Fixes: 03f45c883c6f ("tcp: avoid extra wakeups for SO_RCVLOWAT users")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6cd6cbf593bfa3ae6fc3ed34ac21da4d35045425 ]
When application uses TCP_QUEUE_SEQ socket option to
change tp->rcv_next, we must also update tp->copied_seq.
Otherwise, stuff relying on tcp_inq() being precise can
eventually be confused.
For example, tcp_zerocopy_receive() might crash because
it does not expect tcp_recv_skb() to return NULL.
We could add tests in various places to fix the issue,
or simply make sure tcp_inq() wont return a random value,
and leave fast path as it is.
Note that this fixes ioctl(fd, SIOCINQ, &val) at the same
time.
Fixes: ee9952831cfd ("tcp: Initial repair mode")
Fixes: 05255b823a61 ("tcp: add TCP_ZEROCOPY_RECEIVE support for zerocopy receive")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 784f8344de750a41344f4bbbebb8507a730fc99c ]
tp->segs_in and tp->segs_out need to be cleared in tcp_disconnect().
tcp_disconnect() is rarely used, but it is worth fixing it.
Fixes: 2efd055c53c0 ("tcp: add tcpi_segs_in and tcpi_segs_out to tcp_info")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Marcelo Ricardo Leitner <mleitner@redhat.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit db7ffee6f3eb3683cdcaeddecc0a630a14546fe3 ]
tp->data_segs_in and tp->data_segs_out need to be cleared
in tcp_disconnect().
tcp_disconnect() is rarely used, but it is worth fixing it.
Fixes: a44d6eacdaf5 ("tcp: Add RFC4898 tcpEStatsPerfDataSegsOut/In")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c13c48c00a6bc1febc73902505bdec0967bd7095 ]
total_retrans needs to be cleared in tcp_disconnect().
tcp_disconnect() is rarely used, but it is worth fixing it.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2bec445f9bf35e52e395b971df48d3e1e5dc704a ]
Latest commit 853697504de0 ("tcp: Fix highest_sack and highest_sack_seq")
apparently allowed syzbot to trigger various crashes in TCP stack [1]
I believe this commit only made things easier for syzbot to find
its way into triggering use-after-frees. But really the bugs
could lead to bad TCP behavior or even plain crashes even for
non malicious peers.
I have audited all calls to tcp_rtx_queue_unlink() and
tcp_rtx_queue_unlink_and_free() and made sure tp->highest_sack would be updated
if we are removing from rtx queue the skb that tp->highest_sack points to.
These updates were missing in three locations :
1) tcp_clean_rtx_queue() [This one seems quite serious,
I have no idea why this was not caught earlier]
2) tcp_rtx_queue_purge() [Probably not a big deal for normal operations]
3) tcp_send_synack() [Probably not a big deal for normal operations]
[1]
BUG: KASAN: use-after-free in tcp_highest_sack_seq include/net/tcp.h:1864 [inline]
BUG: KASAN: use-after-free in tcp_highest_sack_seq include/net/tcp.h:1856 [inline]
BUG: KASAN: use-after-free in tcp_check_sack_reordering+0x33c/0x3a0 net/ipv4/tcp_input.c:891
Read of size 4 at addr ffff8880a488d068 by task ksoftirqd/1/16
CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.5.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x197/0x210 lib/dump_stack.c:118
print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
__kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
kasan_report+0x12/0x20 mm/kasan/common.c:639
__asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:134
tcp_highest_sack_seq include/net/tcp.h:1864 [inline]
tcp_highest_sack_seq include/net/tcp.h:1856 [inline]
tcp_check_sack_reordering+0x33c/0x3a0 net/ipv4/tcp_input.c:891
tcp_try_undo_partial net/ipv4/tcp_input.c:2730 [inline]
tcp_fastretrans_alert+0xf74/0x23f0 net/ipv4/tcp_input.c:2847
tcp_ack+0x2577/0x5bf0 net/ipv4/tcp_input.c:3710
tcp_rcv_established+0x6dd/0x1e90 net/ipv4/tcp_input.c:5706
tcp_v4_do_rcv+0x619/0x8d0 net/ipv4/tcp_ipv4.c:1619
tcp_v4_rcv+0x307f/0x3b40 net/ipv4/tcp_ipv4.c:2001
ip_protocol_deliver_rcu+0x5a/0x880 net/ipv4/ip_input.c:204
ip_local_deliver_finish+0x23b/0x380 net/ipv4/ip_input.c:231
NF_HOOK include/linux/netfilter.h:307 [inline]
NF_HOOK include/linux/netfilter.h:301 [inline]
ip_local_deliver+0x1e9/0x520 net/ipv4/ip_input.c:252
dst_input include/net/dst.h:442 [inline]
ip_rcv_finish+0x1db/0x2f0 net/ipv4/ip_input.c:428
NF_HOOK include/linux/netfilter.h:307 [inline]
NF_HOOK include/linux/netfilter.h:301 [inline]
ip_rcv+0xe8/0x3f0 net/ipv4/ip_input.c:538
__netif_receive_skb_one_core+0x113/0x1a0 net/core/dev.c:5148
__netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5262
process_backlog+0x206/0x750 net/core/dev.c:6093
napi_poll net/core/dev.c:6530 [inline]
net_rx_action+0x508/0x1120 net/core/dev.c:6598
__do_softirq+0x262/0x98c kernel/softirq.c:292
run_ksoftirqd kernel/softirq.c:603 [inline]
run_ksoftirqd+0x8e/0x110 kernel/softirq.c:595
smpboot_thread_fn+0x6a3/0xa40 kernel/smpboot.c:165
kthread+0x361/0x430 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Allocated by task 10091:
save_stack+0x23/0x90 mm/kasan/common.c:72
set_track mm/kasan/common.c:80 [inline]
__kasan_kmalloc mm/kasan/common.c:513 [inline]
__kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:486
kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:521
slab_post_alloc_hook mm/slab.h:584 [inline]
slab_alloc_node mm/slab.c:3263 [inline]
kmem_cache_alloc_node+0x138/0x740 mm/slab.c:3575
__alloc_skb+0xd5/0x5e0 net/core/skbuff.c:198
alloc_skb_fclone include/linux/skbuff.h:1099 [inline]
sk_stream_alloc_skb net/ipv4/tcp.c:875 [inline]
sk_stream_alloc_skb+0x113/0xc90 net/ipv4/tcp.c:852
tcp_sendmsg_locked+0xcf9/0x3470 net/ipv4/tcp.c:1282
tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1432
inet_sendmsg+0x9e/0xe0 net/ipv4/af_inet.c:807
sock_sendmsg_nosec net/socket.c:652 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:672
__sys_sendto+0x262/0x380 net/socket.c:1998
__do_sys_sendto net/socket.c:2010 [inline]
__se_sys_sendto net/socket.c:2006 [inline]
__x64_sys_sendto+0xe1/0x1a0 net/socket.c:2006
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 10095:
save_stack+0x23/0x90 mm/kasan/common.c:72
set_track mm/kasan/common.c:80 [inline]
kasan_set_free_info mm/kasan/common.c:335 [inline]
__kasan_slab_free+0x102/0x150 mm/kasan/common.c:474
kasan_slab_free+0xe/0x10 mm/kasan/common.c:483
__cache_free mm/slab.c:3426 [inline]
kmem_cache_free+0x86/0x320 mm/slab.c:3694
kfree_skbmem+0x178/0x1c0 net/core/skbuff.c:645
__kfree_skb+0x1e/0x30 net/core/skbuff.c:681
sk_eat_skb include/net/sock.h:2453 [inline]
tcp_recvmsg+0x1252/0x2930 net/ipv4/tcp.c:2166
inet_recvmsg+0x136/0x610 net/ipv4/af_inet.c:838
sock_recvmsg_nosec net/socket.c:886 [inline]
sock_recvmsg net/socket.c:904 [inline]
sock_recvmsg+0xce/0x110 net/socket.c:900
__sys_recvfrom+0x1ff/0x350 net/socket.c:2055
__do_sys_recvfrom net/socket.c:2073 [inline]
__se_sys_recvfrom net/socket.c:2069 [inline]
__x64_sys_recvfrom+0xe1/0x1a0 net/socket.c:2069
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff8880a488d040
which belongs to the cache skbuff_fclone_cache of size 456
The buggy address is located 40 bytes inside of
456-byte region [ffff8880a488d040, ffff8880a488d208)
The buggy address belongs to the page:
page:ffffea0002922340 refcount:1 mapcount:0 mapping:ffff88821b057000 index:0x0
raw: 00fffe0000000200 ffffea00022a5788 ffffea0002624a48 ffff88821b057000
raw: 0000000000000000 ffff8880a488d040 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8880a488cf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880a488cf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a488d000: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
^
ffff8880a488d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880a488d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
Fixes: 853697504de0 ("tcp: Fix highest_sack and highest_sack_seq")
Fixes: 50895b9de1d3 ("tcp: highest_sack fix")
Fixes: 737ff314563c ("tcp: use sequence distance to detect reordering")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Cambda Zhu <cambda@linux.alibaba.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 216808c6ba6d00169fd2aa928ec3c0e63bef254f upstream.
At the time commit ce5ec440994b ("tcp: ensure epoll edge trigger
wakeup when write queue is empty") was added to the kernel,
we still had a single write queue, combining rtx and write queues.
Once we moved the rtx queue into a separate rb-tree, testing
if sk_write_queue is empty has been suboptimal.
Indeed, if we have packets in the rtx queue, we probably want
to delay the EPOLLOUT generation at the time incoming packets
will free them, making room, but more importantly avoiding
flooding application with EPOLLOUT events.
Solution is to use tcp_rtx_and_write_queues_empty() helper.
Fixes: 75c119afe14f ("tcp: implement rb-tree based retransmit queue")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Busy polling usually runs without locks.
Let's use skb_queue_empty_lockless() instead of skb_queue_empty()
Also uses READ_ONCE() in __skb_try_recv_datagram() to address
a similar potential problem.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Many poll() handlers are lockless. Using skb_queue_empty_lockless()
instead of skb_queue_empty() is more appropriate.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
syzbot found that if __inet_inherit_port() returns an error,
we call tcp_done() after inet_csk_prepare_forced_close(),
meaning the socket lock is no longer held.
We might fix this in a different way in net-next, but
for 5.4 it seems safer to relax the lockdep check.
Fixes: d983ea6f16b8 ("tcp: add rcu protection around tp->fastopen_rsk")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For the sake of tcp_poll(), there are few places where we fetch
sk->sk_wmem_queued while this field can change from IRQ or other cpu.
We need to add READ_ONCE() annotations, and also make sure write
sides use corresponding WRITE_ONCE() to avoid store-tearing.
sk_wmem_queued_add() helper is added so that we can in
the future convert to ADD_ONCE() or equivalent if/when
available.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For the sake of tcp_poll(), there are few places where we fetch
sk->sk_sndbuf while this field can change from IRQ or other cpu.
We need to add READ_ONCE() annotations, and also make sure write
sides use corresponding WRITE_ONCE() to avoid store-tearing.
Note that other transports probably need similar fixes.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For the sake of tcp_poll(), there are few places where we fetch
sk->sk_rcvbuf while this field can change from IRQ or other cpu.
We need to add READ_ONCE() annotations, and also make sure write
sides use corresponding WRITE_ONCE() to avoid store-tearing.
Note that other transports probably need similar fixes.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There two places where we fetch tp->urg_seq while
this field can change from IRQ or other cpu.
We need to add READ_ONCE() annotations, and also make
sure write side use corresponding WRITE_ONCE() to avoid
store-tearing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are few places where we fetch tp->snd_nxt while
this field can change from IRQ or other cpu.
We need to add READ_ONCE() annotations, and also make
sure write sides use corresponding WRITE_ONCE() to avoid
store-tearing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are few places where we fetch tp->write_seq while
this field can change from IRQ or other cpu.
We need to add READ_ONCE() annotations, and also make
sure write sides use corresponding WRITE_ONCE() to avoid
store-tearing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are few places where we fetch tp->copied_seq while
this field can change from IRQ or other cpu.
We need to add READ_ONCE() annotations, and also make
sure write sides use corresponding WRITE_ONCE() to avoid
store-tearing.
Note that tcp_inq_hint() was already using READ_ONCE(tp->copied_seq)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are few places where we fetch tp->rcv_nxt while
this field can change from IRQ or other cpu.
We need to add READ_ONCE() annotations, and also make
sure write sides use corresponding WRITE_ONCE() to avoid
store-tearing.
Note that tcp_inq_hint() was already using READ_ONCE(tp->rcv_nxt)
syzbot reported :
BUG: KCSAN: data-race in tcp_poll / tcp_queue_rcv
write to 0xffff888120425770 of 4 bytes by interrupt on cpu 0:
tcp_rcv_nxt_update net/ipv4/tcp_input.c:3365 [inline]
tcp_queue_rcv+0x180/0x380 net/ipv4/tcp_input.c:4638
tcp_rcv_established+0xbf1/0xf50 net/ipv4/tcp_input.c:5616
tcp_v4_do_rcv+0x381/0x4e0 net/ipv4/tcp_ipv4.c:1542
tcp_v4_rcv+0x1a03/0x1bf0 net/ipv4/tcp_ipv4.c:1923
ip_protocol_deliver_rcu+0x51/0x470 net/ipv4/ip_input.c:204
ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
NF_HOOK include/linux/netfilter.h:305 [inline]
NF_HOOK include/linux/netfilter.h:299 [inline]
ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
dst_input include/net/dst.h:442 [inline]
ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
NF_HOOK include/linux/netfilter.h:305 [inline]
NF_HOOK include/linux/netfilter.h:299 [inline]
ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
__netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5004
__netif_receive_skb+0x37/0xf0 net/core/dev.c:5118
netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5208
napi_skb_finish net/core/dev.c:5671 [inline]
napi_gro_receive+0x28f/0x330 net/core/dev.c:5704
receive_buf+0x284/0x30b0 drivers/net/virtio_net.c:1061
read to 0xffff888120425770 of 4 bytes by task 7254 on cpu 1:
tcp_stream_is_readable net/ipv4/tcp.c:480 [inline]
tcp_poll+0x204/0x6b0 net/ipv4/tcp.c:554
sock_poll+0xed/0x250 net/socket.c:1256
vfs_poll include/linux/poll.h:90 [inline]
ep_item_poll.isra.0+0x90/0x190 fs/eventpoll.c:892
ep_send_events_proc+0x113/0x5c0 fs/eventpoll.c:1749
ep_scan_ready_list.constprop.0+0x189/0x500 fs/eventpoll.c:704
ep_send_events fs/eventpoll.c:1793 [inline]
ep_poll+0xe3/0x900 fs/eventpoll.c:1930
do_epoll_wait+0x162/0x180 fs/eventpoll.c:2294
__do_sys_epoll_pwait fs/eventpoll.c:2325 [inline]
__se_sys_epoll_pwait fs/eventpoll.c:2311 [inline]
__x64_sys_epoll_pwait+0xcd/0x170 fs/eventpoll.c:2311
do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7254 Comm: syz-fuzzer Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
