mirror of https://github.com/torvalds/linux.git
324 Commits
| Author | SHA1 | Message | Date |
|---|---|---|---|
Kuniyuki Iwashima
|
932478bf9f |
tcp: Don't reinitialise tw->tw_transparent in tcp_time_wait().
tw->tw_transparent is initialised twice in inet_twsk_alloc() and tcp_time_wait(). Let's remove the latter. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://patch.msgid.link/20251118000445.4091280-1-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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Kuniyuki Iwashima
|
207ce0f6bc |
tcp: Remove timeout arg from reqsk_timeout().
reqsk_timeout() is always called with @timeout being TCP_RTO_MAX. Let's remove the arg. As a prep for the next patch, reqsk_timeout() is moved to tcp.h and renamed to tcp_reqsk_timeout(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251106003357.273403-5-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
|
Eric Biggers
|
37a183d3b7 |
tcp: Convert tcp-md5 to use MD5 library instead of crypto_ahash
Make tcp-md5 use the MD5 library API (added in 6.18) instead of the
crypto_ahash API. This is much simpler and also more efficient:
- The library API just operates on struct md5_ctx. Just allocate this
struct on the stack instead of using a pool of pre-allocated
crypto_ahash and ahash_request objects.
- The library API accepts standard pointers and doesn't require
scatterlists. So, for hashing the headers just use an on-stack buffer
instead of a pool of pre-allocated kmalloc'ed scratch buffers.
- The library API never fails. Therefore, checking for MD5 hashing
errors is no longer necessary. Update tcp_v4_md5_hash_skb(),
tcp_v6_md5_hash_skb(), tcp_v4_md5_hash_hdr(), tcp_v6_md5_hash_hdr(),
tcp_md5_hash_key(), tcp_sock_af_ops::calc_md5_hash, and
tcp_request_sock_ops::calc_md5_hash to return void instead of int.
- The library API provides direct access to the MD5 code, eliminating
unnecessary overhead such as indirect function calls and scatterlist
management. Microbenchmarks of tcp_v4_md5_hash_skb() on x86_64 show a
speedup from 7518 to 7041 cycles (6% fewer) with skb->len == 1440, or
from 1020 to 678 cycles (33% fewer) with skb->len == 140.
Since tcp_sigpool_hash_skb_data() can no longer be used, add a function
tcp_md5_hash_skb_data() which is specialized to MD5. Of course, to the
extent that this duplicates any code, it's well worth it.
To preserve the existing behavior of TCP-MD5 support being disabled when
the kernel is booted with "fips=1", make tcp_md5_do_add() check
fips_enabled itself. Previously it relied on the error from
crypto_alloc_ahash("md5") being bubbled up. I don't know for sure that
this is actually needed, but this preserves the existing behavior.
Tested with bidirectional TCP-MD5, both IPv4 and IPv6, between a kernel
that includes this commit and a kernel that doesn't include this commit.
(Side note: please don't use TCP-MD5! It's cryptographically weak. But
as long as Linux supports it, it might as well be implemented properly.)
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Link: https://patch.msgid.link/20251014215836.115616-1-ebiggers@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Jakub Kicinski
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659a2899a5 |
tcp: add datapath logic for PSP with inline key exchange
Add validation points and state propagation to support PSP key exchange inline, on TCP connections. The expectation is that application will use some well established mechanism like TLS handshake to establish a secure channel over the connection and if both endpoints are PSP-capable - exchange and install PSP keys. Because the connection can existing in PSP-unsecured and PSP-secured state we need to make sure that there are no race conditions or retransmission leaks. On Tx - mark packets with the skb->decrypted bit when PSP key is at the enqueue time. Drivers should only encrypt packets with this bit set. This prevents retransmissions getting encrypted when original transmission was not. Similarly to TLS, we'll use sk->sk_validate_xmit_skb to make sure PSP skbs can't "escape" via a PSP-unaware device without being encrypted. On Rx - validation is done under socket lock. This moves the validation point later than xfrm, for example. Please see the documentation patch for more details on the flow of securing a connection, but for the purpose of this patch what's important is that we want to enforce the invariant that once connection is secured any skb in the receive queue has been encrypted with PSP. Add GRO and coalescing checks to prevent PSP authenticated data from being combined with cleartext data, or data with non-matching PSP state. On Rx, check skb's with psp_skb_coalesce_diff() at points before psp_sk_rx_policy_check(). After skb's are policy checked and on the socket receive queue, skb_cmp_decrypted() is sufficient for checking for coalescable PSP state. On Tx, tcp_write_collapse_fence() should be called when transitioning a socket into PSP Tx state to prevent data sent as cleartext from being coalesced with PSP encapsulated data. This change only adds the validation points, for ease of review. Subsequent change will add the ability to install keys, and flesh the enforcement logic out Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Co-developed-by: Daniel Zahka <daniel.zahka@gmail.com> Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250917000954.859376-5-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> |
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Jakub Kicinski
|
ed8a507b74 |
net: modify core data structures for PSP datapath support
Add pointers to psp data structures to core networking structs, and an SKB extension to carry the PSP information from the drivers to the socket layer. Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Co-developed-by: Daniel Zahka <daniel.zahka@gmail.com> Signed-off-by: Daniel Zahka <daniel.zahka@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250917000954.859376-4-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> |
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Chia-Yu Chang
|
b40671b5ee |
tcp: accecn: AccECN option failure handling
AccECN option may fail in various way, handle these:
- Attempt to negotiate the use of AccECN on the 1st retransmitted SYN
- From the 2nd retransmitted SYN, stop AccECN negotiation
- Remove option from SYN/ACK rexmits to handle blackholes
- If no option arrives in SYN/ACK, assume Option is not usable
- If an option arrives later, re-enabled
- If option is zeroed, disable AccECN option processing
This patch use existing padding bits in tcp_request_sock and
holes in tcp_sock without increasing the size.
Signed-off-by: Ilpo Järvinen <ij@kernel.org>
Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250916082434.100722-9-chia-yu.chang@nokia-bell-labs.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Chia-Yu Chang
|
aa55a7dde7 |
tcp: accecn: AccECN option send control
Instead of sending the option in every ACK, limit sending to
those ACKs where the option is necessary:
- Handshake
- "Change-triggered ACK" + the ACK following it. The
2nd ACK is necessary to unambiguously indicate which
of the ECN byte counters in increasing. The first
ACK has two counters increasing due to the ecnfield
edge.
- ACKs with CE to allow CEP delta validations to take
advantage of the option.
- Force option to be sent every at least once per 2^22
bytes. The check is done using the bit edges of the
byte counters (avoids need for extra variables).
- AccECN option beacon to send a few times per RTT even if
nothing in the ECN state requires that. The default is 3
times per RTT, and its period can be set via
sysctl_tcp_ecn_option_beacon.
Below are the pahole outcomes before and after this patch,
in which the group size of tcp_sock_write_tx is increased
from 89 to 97 due to the new u64 accecn_opt_tstamp member:
[BEFORE THIS PATCH]
struct tcp_sock {
[...]
u64 tcp_wstamp_ns; /* 2488 8 */
struct list_head tsorted_sent_queue; /* 2496 16 */
[...]
__cacheline_group_end__tcp_sock_write_tx[0]; /* 2521 0 */
__cacheline_group_begin__tcp_sock_write_txrx[0]; /* 2521 0 */
u8 nonagle:4; /* 2521: 0 1 */
u8 rate_app_limited:1; /* 2521: 4 1 */
/* XXX 3 bits hole, try to pack */
/* Force alignment to the next boundary: */
u8 :0;
u8 received_ce_pending:4;/* 2522: 0 1 */
u8 unused2:4; /* 2522: 4 1 */
u8 accecn_minlen:2; /* 2523: 0 1 */
u8 est_ecnfield:2; /* 2523: 2 1 */
u8 unused3:4; /* 2523: 4 1 */
[...]
__cacheline_group_end__tcp_sock_write_txrx[0]; /* 2628 0 */
[...]
/* size: 3200, cachelines: 50, members: 171 */
}
[AFTER THIS PATCH]
struct tcp_sock {
[...]
u64 tcp_wstamp_ns; /* 2488 8 */
u64 accecn_opt_tstamp; /* 2596 8 */
struct list_head tsorted_sent_queue; /* 2504 16 */
[...]
__cacheline_group_end__tcp_sock_write_tx[0]; /* 2529 0 */
__cacheline_group_begin__tcp_sock_write_txrx[0]; /* 2529 0 */
u8 nonagle:4; /* 2529: 0 1 */
u8 rate_app_limited:1; /* 2529: 4 1 */
/* XXX 3 bits hole, try to pack */
/* Force alignment to the next boundary: */
u8 :0;
u8 received_ce_pending:4;/* 2530: 0 1 */
u8 unused2:4; /* 2530: 4 1 */
u8 accecn_minlen:2; /* 2531: 0 1 */
u8 est_ecnfield:2; /* 2531: 2 1 */
u8 accecn_opt_demand:2; /* 2531: 4 1 */
u8 prev_ecnfield:2; /* 2531: 6 1 */
[...]
__cacheline_group_end__tcp_sock_write_txrx[0]; /* 2636 0 */
[...]
/* size: 3200, cachelines: 50, members: 173 */
}
Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>
Co-developed-by: Ilpo Järvinen <ij@kernel.org>
Signed-off-by: Ilpo Järvinen <ij@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250916082434.100722-8-chia-yu.chang@nokia-bell-labs.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Ilpo Järvinen
|
9a01127744 |
tcp: accecn: add AccECN rx byte counters
These three byte counters track IP ECN field payload byte sums for
all arriving (acceptable) packets for ECT0, ECT1, and CE. The
AccECN option (added by a later patch in the series) echoes these
counters back to sender side; therefore, it is placed within the
group of tcp_sock_write_txrx.
Below are the pahole outcomes before and after this patch, in which
the group size of tcp_sock_write_txrx is increased from 95 + 4 to
107 + 4 and an extra 4-byte hole is created but will be exploited
in later patches:
[BEFORE THIS PATCH]
struct tcp_sock {
[...]
u32 delivered_ce; /* 2576 4 */
u32 received_ce; /* 2580 4 */
u32 app_limited; /* 2584 4 */
u32 rcv_wnd; /* 2588 4 */
struct tcp_options_received rx_opt; /* 2592 24 */
__cacheline_group_end__tcp_sock_write_txrx[0]; /* 2616 0 */
[...]
/* size: 3200, cachelines: 50, members: 166 */
}
[AFTER THIS PATCH]
struct tcp_sock {
[...]
u32 delivered_ce; /* 2576 4 */
u32 received_ce; /* 2580 4 */
u32 received_ecn_bytes[3];/* 2584 12 */
u32 app_limited; /* 2596 4 */
u32 rcv_wnd; /* 2600 4 */
struct tcp_options_received rx_opt; /* 2604 24 */
__cacheline_group_end__tcp_sock_write_txrx[0]; /* 2628 0 */
/* XXX 4 bytes hole, try to pack */
[...]
/* size: 3200, cachelines: 50, members: 167 */
}
Signed-off-by: Ilpo Järvinen <ij@kernel.org>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Co-developed-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>
Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250916082434.100722-4-chia-yu.chang@nokia-bell-labs.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Ilpo Järvinen
|
3cae34274c |
tcp: accecn: AccECN negotiation
Accurate ECN negotiation parts based on the specification: https://tools.ietf.org/id/draft-ietf-tcpm-accurate-ecn-28.txt Accurate ECN is negotiated using ECE, CWR and AE flags in the TCP header. TCP falls back into using RFC3168 ECN if one of the ends supports only RFC3168-style ECN. The AccECN negotiation includes reflecting IP ECN field value seen in SYN and SYNACK back using the same bits as negotiation to allow responding to SYN CE marks and to detect ECN field mangling. CE marks should not occur currently because SYN=1 segments are sent with Non-ECT in IP ECN field (but proposal exists to remove this restriction). Reflecting SYN IP ECN field in SYNACK is relatively simple. Reflecting SYNACK IP ECN field in the final/third ACK of the handshake is more challenging. Linux TCP code is not well prepared for using the final/third ACK a signalling channel which makes things somewhat complicated here. tcp_ecn sysctl can be used to select the highest ECN variant (Accurate ECN, ECN, No ECN) that is attemped to be negotiated and requested for incoming connection and outgoing connection: TCP_ECN_IN_NOECN_OUT_NOECN, TCP_ECN_IN_ECN_OUT_ECN, TCP_ECN_IN_ECN_OUT_NOECN, TCP_ECN_IN_ACCECN_OUT_ACCECN, TCP_ECN_IN_ACCECN_OUT_ECN, and TCP_ECN_IN_ACCECN_OUT_NOECN. After this patch, the size of tcp_request_sock remains unchanged and no new holes are added. Below are the pahole outcomes before and after this patch: [BEFORE THIS PATCH] struct tcp_request_sock { [...] u32 rcv_nxt; /* 352 4 */ u8 syn_tos; /* 356 1 */ /* size: 360, cachelines: 6, members: 16 */ } [AFTER THIS PATCH] struct tcp_request_sock { [...] u32 rcv_nxt; /* 352 4 */ u8 syn_tos; /* 356 1 */ bool accecn_ok; /* 357 1 */ u8 syn_ect_snt:2; /* 358: 0 1 */ u8 syn_ect_rcv:2; /* 358: 2 1 */ u8 accecn_fail_mode:4; /* 358: 4 1 */ /* size: 360, cachelines: 6, members: 20 */ } After this patch, the size of tcp_sock remains unchanged and no new holes are added. Also, 4 bits of the existing 2-byte hole are exploited. Below are the pahole outcomes before and after this patch: [BEFORE THIS PATCH] struct tcp_sock { [...] u8 dup_ack_counter:2; /* 2761: 0 1 */ u8 tlp_retrans:1; /* 2761: 2 1 */ u8 unused:5; /* 2761: 3 1 */ u8 thin_lto:1; /* 2762: 0 1 */ u8 fastopen_connect:1; /* 2762: 1 1 */ u8 fastopen_no_cookie:1; /* 2762: 2 1 */ u8 fastopen_client_fail:2; /* 2762: 3 1 */ u8 frto:1; /* 2762: 5 1 */ /* XXX 2 bits hole, try to pack */ [...] u8 keepalive_probes; /* 2765 1 */ /* XXX 2 bytes hole, try to pack */ [...] /* size: 3200, cachelines: 50, members: 164 */ } [AFTER THIS PATCH] struct tcp_sock { [...] u8 dup_ack_counter:2; /* 2761: 0 1 */ u8 tlp_retrans:1; /* 2761: 2 1 */ u8 syn_ect_snt:2; /* 2761: 3 1 */ u8 syn_ect_rcv:2; /* 2761: 5 1 */ u8 thin_lto:1; /* 2761: 7 1 */ u8 fastopen_connect:1; /* 2762: 0 1 */ u8 fastopen_no_cookie:1; /* 2762: 1 1 */ u8 fastopen_client_fail:2; /* 2762: 2 1 */ u8 frto:1; /* 2762: 4 1 */ /* XXX 3 bits hole, try to pack */ [...] u8 keepalive_probes; /* 2765 1 */ u8 accecn_fail_mode:4; /* 2766: 0 1 */ /* XXX 4 bits hole, try to pack */ /* XXX 1 byte hole, try to pack */ [...] /* size: 3200, cachelines: 50, members: 166 */ } Signed-off-by: Ilpo Järvinen <ij@kernel.org> Co-developed-by: Olivier Tilmans <olivier.tilmans@nokia.com> Signed-off-by: Olivier Tilmans <olivier.tilmans@nokia.com> Co-developed-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250916082434.100722-3-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> |
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Dmitry Safonov
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51e547e8c8 |
tcp: Free TCP-AO/TCP-MD5 info/keys without RCU
Now that the destruction of info/keys is delayed until the socket destructor, it's safe to use kfree() without an RCU callback. The socket is in TCP_CLOSE state either because it never left it, or it's already closed and the refcounter is zero. In any way, no one can discover it anymore, it's safe to release memory straight away. Similar thing was possible for twsk already. Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Link: https://patch.msgid.link/20250909-b4-tcp-ao-md5-rst-finwait2-v5-2-9ffaaaf8b236@arista.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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Kuniyuki Iwashima
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2d842b6c67 |
tcp: Remove timewait_sock_ops.twsk_destructor().
Since DCCP has been removed, sk->sk_prot->twsk_prot->twsk_destructor is always tcp_twsk_destructor(). Let's call tcp_twsk_destructor() directly in inet_twsk_free() and remove ->twsk_destructor(). While at it, tcp_twsk_destructor() is un-exported. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250822190803.540788-3-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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Eric Dumazet
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cf56a98202 |
tcp: remove inet_rtx_syn_ack()
inet_rtx_syn_ack() is a simple wrapper around tcp_rtx_synack(), if we move req->num_retrans update. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250626153017.2156274-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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Jiayuan Chen
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c449d5f3a3 |
tcp: add LINUX_MIB_PAWS_TW_REJECTED counter
When TCP is in TIME_WAIT state, PAWS verification uses LINUX_PAWSESTABREJECTED, which is ambiguous and cannot be distinguished from other PAWS verification processes. We added a new counter, like the existing PAWS_OLD_ACK one. Also we update the doc with previously missing PAWS_OLD_ACK. usage: ''' nstat -az | grep PAWSTimewait TcpExtPAWSTimewait 1 0.0 ''' Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250409112614.16153-3-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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Jiayuan Chen
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0427141112 |
tcp: add TCP_RFC7323_TW_PAWS drop reason
Devices in the networking path, such as firewalls, NATs, or routers, which
can perform SNAT or DNAT, use addresses from their own limited address
pools to masquerade the source address during forwarding, causing PAWS
verification to fail more easily.
Currently, packet loss statistics for PAWS can only be viewed through MIB,
which is a global metric and cannot be precisely obtained through tracing
to get the specific 4-tuple of the dropped packet. In the past, we had to
use kprobe ret to retrieve relevant skb information from
tcp_timewait_state_process().
We add a drop_reason pointer, similar to what previous commit does:
commit
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Ilpo Järvinen
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4618e195f9 |
tcp: add new TCP_TW_ACK_OOW state and allow ECN bits in TOS
ECN bits in TOS are always cleared when sending in ACKs in TW. Clearing them is problematic for TCP flows that used Accurate ECN because ECN bits decide which service queue the packet is placed into (L4S vs Classic). Effectively, TW ACKs are always downgraded from L4S to Classic queue which might impact, e.g., delay the ACK will experience on the path compared with the other packets of the flow. Change the TW ACK sending code to differentiate: - In tcp_v4_send_reset(), commit |
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Ilpo Järvinen
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041fb11d51 |
tcp: helpers for ECN mode handling
Create helpers for TCP ECN modes. No functional changes. Signed-off-by: Ilpo Järvinen <ij@kernel.org> Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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Eric Dumazet
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5282de1762 |
tcp: remove READ_ONCE(req->ts_recent)
After commit |
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Eric Dumazet
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a11a791ca8 |
tcp: add four drop reasons to tcp_check_req()
Use two existing drop reasons in tcp_check_req(): - TCP_RFC7323_PAWS - TCP_OVERWINDOW Add two new ones: - TCP_RFC7323_TSECR (corresponds to LINUX_MIB_TSECRREJECTED) - TCP_LISTEN_OVERFLOW (when a listener accept queue is full) Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250301201424.2046477-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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Eric Dumazet
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e34100c2ec |
tcp: add a drop_reason pointer to tcp_check_req()
We want to add new drop reasons for packets dropped in 3WHS in the following patches. tcp_rcv_state_process() has to set reason to TCP_FASTOPEN, because tcp_check_req() will conditionally overwrite the drop_reason. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250301201424.2046477-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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Jakub Kicinski
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357660d759 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR (net-6.14-rc5). Conflicts: drivers/net/ethernet/cadence/macb_main.c |
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Eric Dumazet
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3ba075278c |
tcp: be less liberal in TSEcr received while in SYN_RECV state
Yong-Hao Zou mentioned that linux was not strict as other OS in 3WHS,
for flows using TCP TS option (RFC 7323)
As hinted by an old comment in tcp_check_req(),
we can check the TSEcr value in the incoming packet corresponds
to one of the SYNACK TSval values we have sent.
In this patch, I record the oldest and most recent values
that SYNACK packets have used.
Send a challenge ACK if we receive a TSEcr outside
of this range, and increase a new SNMP counter.
nstat -az | grep TSEcrRejected
TcpExtTSEcrRejected 0 0.0
Due to TCP fastopen implementation, do not apply yet these checks
for fastopen flows.
v2: No longer use req->num_timeout, but treq->snt_tsval_first
to detect when first SYNACK is prepared. This means
we make sure to not send an initial zero TSval.
Make sure MPTCP and TCP selftests are passing.
Change MIB name to TcpExtTSEcrRejected
v1: https://lore.kernel.org/netdev/CADVnQykD8i4ArpSZaPKaoNxLJ2if2ts9m4As+=Jvdkrgx1qMHw@mail.gmail.com/T/
Reported-by: Yong-Hao Zou <yonghaoz1994@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250225171048.3105061-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Wang Hai
|
8d52da23b6 |
tcp: Defer ts_recent changes until req is owned
Recently a bug was discovered where the server had entered TCP_ESTABLISHED
state, but the upper layers were not notified.
The same 5-tuple packet may be processed by different CPUSs, so two
CPUs may receive different ack packets at the same time when the
state is TCP_NEW_SYN_RECV.
In that case, req->ts_recent in tcp_check_req may be changed concurrently,
which will probably cause the newsk's ts_recent to be incorrectly large.
So that tcp_validate_incoming will fail. At this point, newsk will not be
able to enter the TCP_ESTABLISHED.
cpu1 cpu2
tcp_check_req
tcp_check_req
req->ts_recent = rcv_tsval = t1
req->ts_recent = rcv_tsval = t2
syn_recv_sock
tcp_sk(child)->rx_opt.ts_recent = req->ts_recent = t2 // t1 < t2
tcp_child_process
tcp_rcv_state_process
tcp_validate_incoming
tcp_paws_check
if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win)
// t2 - t1 > paws_win, failed
tcp_v4_do_rcv
tcp_rcv_state_process
// TCP_ESTABLISHED
The cpu2's skb or a newly received skb will call tcp_v4_do_rcv to get
the newsk into the TCP_ESTABLISHED state, but at this point it is no
longer possible to notify the upper layer application. A notification
mechanism could be added here, but the fix is more complex, so the
current fix is used.
In tcp_check_req, req->ts_recent is used to assign a value to
tcp_sk(child)->rx_opt.ts_recent, so removing the change in req->ts_recent
and changing tcp_sk(child)->rx_opt.ts_recent directly after owning the
req fixes this bug.
Fixes:
|
|
|
Eric Dumazet
|
6dc4c2526f |
tcp: use EXPORT_IPV6_MOD[_GPL]()
Use EXPORT_IPV6_MOD[_GPL]() for symbols that don't need to be exported unless CONFIG_IPV6=m tcp_hashinfo and tcp_openreq_init_rwin() are no longer used from any module anyway. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Mateusz Polchlopek <mateusz.polchlopek@intel.com> Link: https://patch.msgid.link/20250212132418.1524422-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
|
|
Eric Dumazet
|
be258f654a |
tcp: rename inet_csk_{delete|reset}_keepalive_timer()
inet_csk_delete_keepalive_timer() and inet_csk_reset_keepalive_timer() are only used from core TCP, there is no need to export them. Replace their prefix by tcp. Move them to net/ipv4/tcp_timer.c and make tcp_delete_keepalive_timer() static. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Reviewed-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250206094605.2694118-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
|
Jakub Sitnicki
|
19ce8cd304 |
tcp: Measure TIME-WAIT reuse delay with millisecond precision
Prepare ground for TIME-WAIT socket reuse with subsecond delay. Today the last TS.Recent update timestamp, recorded in seconds and stored tp->ts_recent_stamp and tw->tw_ts_recent_stamp fields, has two purposes. Firstly, it is used to track the age of the last recorded TS.Recent value to detect when that value becomes outdated due to potential wrap-around of the other TCP timestamp clock (RFC 7323, section 5.5). For this purpose a second-based timestamp is completely sufficient as even in the worst case scenario of a peer using a high resolution microsecond timestamp, the wrap-around interval is ~36 minutes long. Secondly, it serves as a threshold value for allowing TIME-WAIT socket reuse. A TIME-WAIT socket can be reused only once the virtual 1 Hz clock, ktime_get_seconds, is past the TS.Recent update timestamp. The purpose behind delaying the TIME-WAIT socket reuse is to wait for the other TCP timestamp clock to tick at least once before reusing the connection. It is only then that the PAWS mechanism for the reopened connection can detect old duplicate segments from the previous connection incarnation (RFC 7323, appendix B.2). In this case using a timestamp with second resolution not only blocks the way toward allowing faster TIME-WAIT reuse after shorter subsecond delay, but also makes it impossible to reliably delay TW reuse by one second. As Eric Dumazet has pointed out [1], due to timestamp rounding, the TW reuse delay will actually be between (0, 1] seconds, and 0.5 seconds on average. We delay TW reuse for one full second only when last TS.Recent update coincides with our virtual 1 Hz clock tick. Considering the above, introduce a dedicated field to store a millisecond timestamp of transition into the TIME-WAIT state. Place it in an existing 4-byte hole inside inet_timewait_sock structure to avoid an additional memory cost. Use the new timestamp to (i) reliably delay TIME-WAIT reuse by one second, and (ii) prepare for configurable subsecond reuse delay in the subsequent change. We assume here that a full one second delay was the original intention in [2] because it accounts for the worst case scenario of the other TCP using the slowest recommended 1 Hz timestamp clock. A more involved alternative would be to change the resolution of the last TS.Recent update timestamp, tw->tw_ts_recent_stamp, to milliseconds. [1] https://lore.kernel.org/netdev/CANn89iKB4GFd8sVzCbRttqw_96o3i2wDhX-3DraQtsceNGYwug@mail.gmail.com/ [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b8439924316d5bcb266d165b93d632a4b4b859af Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://patch.msgid.link/20241209-jakub-krn-909-poc-msec-tw-tstamp-v2-1-66aca0eed03e@cloudflare.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
|
|
Eric Dumazet
|
0a4cc4accf |
tcp: populate XPS related fields of timewait sockets
syzbot reported that netdev_core_pick_tx() was reading an uninitialized field [1]. This is indeed hapening for timewait sockets after recent commits. We can copy the original established socket sk_tx_queue_mapping and sk_rx_queue_mapping fields, instead of adding more checks in fast paths. As a bonus, packets will use the same transmit queue than prior ones, this potentially can avoid reordering. [1] BUG: KMSAN: uninit-value in netdev_pick_tx+0x5c7/0x1550 netdev_pick_tx+0x5c7/0x1550 netdev_core_pick_tx+0x1d2/0x4a0 net/core/dev.c:4312 __dev_queue_xmit+0x128a/0x57d0 net/core/dev.c:4394 dev_queue_xmit include/linux/netdevice.h:3168 [inline] neigh_hh_output include/net/neighbour.h:523 [inline] neigh_output include/net/neighbour.h:537 [inline] ip_finish_output2+0x187c/0x1b70 net/ipv4/ip_output.c:236 __ip_finish_output+0x287/0x810 ip_finish_output+0x4b/0x600 net/ipv4/ip_output.c:324 NF_HOOK_COND include/linux/netfilter.h:303 [inline] ip_output+0x15f/0x3f0 net/ipv4/ip_output.c:434 dst_output include/net/dst.h:450 [inline] ip_local_out net/ipv4/ip_output.c:130 [inline] ip_send_skb net/ipv4/ip_output.c:1505 [inline] ip_push_pending_frames+0x444/0x570 net/ipv4/ip_output.c:1525 ip_send_unicast_reply+0x18c1/0x1b30 net/ipv4/ip_output.c:1672 tcp_v4_send_reset+0x238d/0x2a40 net/ipv4/tcp_ipv4.c:910 tcp_v4_rcv+0x48f8/0x5750 net/ipv4/tcp_ipv4.c:2431 ip_protocol_deliver_rcu+0x2a3/0x13d0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x336/0x500 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] ip_local_deliver+0x21f/0x490 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:460 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:578 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:628 [inline] ip_sublist_rcv+0x15f3/0x17f0 net/ipv4/ip_input.c:636 ip_list_rcv+0x9ef/0xa40 net/ipv4/ip_input.c:670 __netif_receive_skb_list_ptype net/core/dev.c:5715 [inline] __netif_receive_skb_list_core+0x15c5/0x1670 net/core/dev.c:5762 __netif_receive_skb_list net/core/dev.c:5814 [inline] netif_receive_skb_list_internal+0x1085/0x1700 net/core/dev.c:5905 gro_normal_list include/net/gro.h:515 [inline] napi_complete_done+0x3d4/0x810 net/core/dev.c:6256 virtqueue_napi_complete drivers/net/virtio_net.c:758 [inline] virtnet_poll+0x5d80/0x6bf0 drivers/net/virtio_net.c:3013 __napi_poll+0xe7/0x980 net/core/dev.c:6877 napi_poll net/core/dev.c:6946 [inline] net_rx_action+0xa5a/0x19b0 net/core/dev.c:7068 handle_softirqs+0x1a0/0x7c0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0x68/0x180 kernel/softirq.c:655 irq_exit_rcu+0x12/0x20 kernel/softirq.c:671 common_interrupt+0x97/0xb0 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x2b/0x40 arch/x86/include/asm/idtentry.h:693 __preempt_count_sub arch/x86/include/asm/preempt.h:84 [inline] kmsan_virt_addr_valid arch/x86/include/asm/kmsan.h:95 [inline] virt_to_page_or_null+0xfb/0x150 mm/kmsan/shadow.c:75 kmsan_get_metadata+0x13e/0x1c0 mm/kmsan/shadow.c:141 kmsan_get_shadow_origin_ptr+0x4d/0xb0 mm/kmsan/shadow.c:102 get_shadow_origin_ptr mm/kmsan/instrumentation.c:38 [inline] __msan_metadata_ptr_for_store_4+0x27/0x40 mm/kmsan/instrumentation.c:93 rcu_preempt_read_enter kernel/rcu/tree_plugin.h:390 [inline] __rcu_read_lock+0x46/0x70 kernel/rcu/tree_plugin.h:413 rcu_read_lock include/linux/rcupdate.h:847 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x114/0x19e0 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3310 worker_thread+0xea7/0x14f0 kernel/workqueue.c:3391 kthread+0x3e2/0x540 kernel/kthread.c:389 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Uninit was created at: __alloc_pages_noprof+0x9a7/0xe00 mm/page_alloc.c:4774 alloc_pages_mpol_noprof+0x299/0x990 mm/mempolicy.c:2265 alloc_pages_noprof+0x1bf/0x1e0 mm/mempolicy.c:2344 alloc_slab_page mm/slub.c:2412 [inline] allocate_slab+0x320/0x12e0 mm/slub.c:2578 new_slab mm/slub.c:2631 [inline] ___slab_alloc+0x12ef/0x35e0 mm/slub.c:3818 __slab_alloc mm/slub.c:3908 [inline] __slab_alloc_node mm/slub.c:3961 [inline] slab_alloc_node mm/slub.c:4122 [inline] kmem_cache_alloc_noprof+0x57a/0xb20 mm/slub.c:4141 inet_twsk_alloc+0x11f/0x9d0 net/ipv4/inet_timewait_sock.c:188 tcp_time_wait+0x83/0xf50 net/ipv4/tcp_minisocks.c:309 tcp_rcv_state_process+0x145a/0x49d0 tcp_v4_do_rcv+0xbf9/0x11a0 net/ipv4/tcp_ipv4.c:1939 tcp_v4_rcv+0x51df/0x5750 net/ipv4/tcp_ipv4.c:2351 ip_protocol_deliver_rcu+0x2a3/0x13d0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x336/0x500 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] ip_local_deliver+0x21f/0x490 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:460 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:578 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:628 [inline] ip_sublist_rcv+0x15f3/0x17f0 net/ipv4/ip_input.c:636 ip_list_rcv+0x9ef/0xa40 net/ipv4/ip_input.c:670 __netif_receive_skb_list_ptype net/core/dev.c:5715 [inline] __netif_receive_skb_list_core+0x15c5/0x1670 net/core/dev.c:5762 __netif_receive_skb_list net/core/dev.c:5814 [inline] netif_receive_skb_list_internal+0x1085/0x1700 net/core/dev.c:5905 gro_normal_list include/net/gro.h:515 [inline] napi_complete_done+0x3d4/0x810 net/core/dev.c:6256 virtqueue_napi_complete drivers/net/virtio_net.c:758 [inline] virtnet_poll+0x5d80/0x6bf0 drivers/net/virtio_net.c:3013 __napi_poll+0xe7/0x980 net/core/dev.c:6877 napi_poll net/core/dev.c:6946 [inline] net_rx_action+0xa5a/0x19b0 net/core/dev.c:7068 handle_softirqs+0x1a0/0x7c0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0x68/0x180 kernel/softirq.c:655 irq_exit_rcu+0x12/0x20 kernel/softirq.c:671 common_interrupt+0x97/0xb0 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x2b/0x40 arch/x86/include/asm/idtentry.h:693 CPU: 0 UID: 0 PID: 3962 Comm: kworker/u8:18 Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: bat_events batadv_nc_worker Fixes: |
|
Mina Almasry
|
8f0b3cc9a4 |
tcp: RX path for devmem TCP
In tcp_recvmsg_locked(), detect if the skb being received by the user is a devmem skb. In this case - if the user provided the MSG_SOCK_DEVMEM flag - pass it to tcp_recvmsg_devmem() for custom handling. tcp_recvmsg_devmem() copies any data in the skb header to the linear buffer, and returns a cmsg to the user indicating the number of bytes returned in the linear buffer. tcp_recvmsg_devmem() then loops over the unaccessible devmem skb frags, and returns to the user a cmsg_devmem indicating the location of the data in the dmabuf device memory. cmsg_devmem contains this information: 1. the offset into the dmabuf where the payload starts. 'frag_offset'. 2. the size of the frag. 'frag_size'. 3. an opaque token 'frag_token' to return to the kernel when the buffer is to be released. The pages awaiting freeing are stored in the newly added sk->sk_user_frags, and each page passed to userspace is get_page()'d. This reference is dropped once the userspace indicates that it is done reading this page. All pages are released when the socket is destroyed. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com> Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240910171458.219195-10-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
|
|
Eric Dumazet
|
c0a11493ee |
tcp: annotate data-races around tcptw->tw_rcv_nxt
No lock protects tcp tw fields. tcptw->tw_rcv_nxt can be changed from twsk_rcv_nxt_update() while other threads might read this field. Add READ_ONCE()/WRITE_ONCE() annotations, and make sure tcp_timewait_state_process() reads tcptw->tw_rcv_nxt only once. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://patch.msgid.link/20240827015250.3509197-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
|
|
Eric Dumazet
|
3e5cbbb1fb |
tcp: remove volatile qualifier on tw_substate
Using a volatile qualifier for a specific struct field is unusual. Use instead READ_ONCE()/WRITE_ONCE() where necessary. tcp_timewait_state_process() can change tw_substate while other threads are reading this field. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://patch.msgid.link/20240827015250.3509197-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
|
Kuniyuki Iwashima
|
3f45181358 |
tcp: Don't access uninit tcp_rsk(req)->ao_keyid in tcp_create_openreq_child().
syzkaller reported KMSAN splat in tcp_create_openreq_child(). [0]
The uninit variable is tcp_rsk(req)->ao_keyid.
tcp_rsk(req)->ao_keyid is initialised only when tcp_conn_request() finds
a valid TCP AO option in SYN. Then, tcp_rsk(req)->used_tcp_ao is set
accordingly.
Let's not read tcp_rsk(req)->ao_keyid when tcp_rsk(req)->used_tcp_ao is
false.
[0]:
BUG: KMSAN: uninit-value in tcp_create_openreq_child+0x198b/0x1ff0 net/ipv4/tcp_minisocks.c:610
tcp_create_openreq_child+0x198b/0x1ff0 net/ipv4/tcp_minisocks.c:610
tcp_v4_syn_recv_sock+0x18e/0x2170 net/ipv4/tcp_ipv4.c:1754
tcp_check_req+0x1a3e/0x20c0 net/ipv4/tcp_minisocks.c:852
tcp_v4_rcv+0x26a4/0x53a0 net/ipv4/tcp_ipv4.c:2265
ip_protocol_deliver_rcu+0x884/0x1270 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x30f/0x530 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:314 [inline]
ip_local_deliver+0x230/0x4c0 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:460 [inline]
ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline]
ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline]
ip_sublist_rcv+0x10f7/0x13e0 net/ipv4/ip_input.c:639
ip_list_rcv+0x952/0x9c0 net/ipv4/ip_input.c:674
__netif_receive_skb_list_ptype net/core/dev.c:5703 [inline]
__netif_receive_skb_list_core+0xd92/0x11d0 net/core/dev.c:5751
__netif_receive_skb_list net/core/dev.c:5803 [inline]
netif_receive_skb_list_internal+0xd8f/0x1350 net/core/dev.c:5895
gro_normal_list include/net/gro.h:515 [inline]
napi_complete_done+0x3f2/0x990 net/core/dev.c:6246
e1000_clean+0x1fa4/0x5e50 drivers/net/ethernet/intel/e1000/e1000_main.c:3808
__napi_poll+0xd9/0x990 net/core/dev.c:6771
napi_poll net/core/dev.c:6840 [inline]
net_rx_action+0x90f/0x17e0 net/core/dev.c:6962
handle_softirqs+0x152/0x6b0 kernel/softirq.c:554
__do_softirq kernel/softirq.c:588 [inline]
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu kernel/softirq.c:637 [inline]
irq_exit_rcu+0x5d/0x120 kernel/softirq.c:649
common_interrupt+0x83/0x90 arch/x86/kernel/irq.c:278
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
__msan_instrument_asm_store+0xd6/0xe0
arch_atomic_inc arch/x86/include/asm/atomic.h:53 [inline]
raw_atomic_inc include/linux/atomic/atomic-arch-fallback.h:992 [inline]
atomic_inc include/linux/atomic/atomic-instrumented.h:436 [inline]
page_ref_inc include/linux/page_ref.h:153 [inline]
folio_ref_inc include/linux/page_ref.h:160 [inline]
filemap_map_order0_folio mm/filemap.c:3596 [inline]
filemap_map_pages+0x11c7/0x2270 mm/filemap.c:3644
do_fault_around mm/memory.c:4879 [inline]
do_read_fault mm/memory.c:4912 [inline]
do_fault mm/memory.c:5051 [inline]
do_pte_missing mm/memory.c:3897 [inline]
handle_pte_fault mm/memory.c:5381 [inline]
__handle_mm_fault mm/memory.c:5524 [inline]
handle_mm_fault+0x3677/0x6f00 mm/memory.c:5689
do_user_addr_fault+0x1373/0x2b20 arch/x86/mm/fault.c:1338
handle_page_fault arch/x86/mm/fault.c:1481 [inline]
exc_page_fault+0x54/0xc0 arch/x86/mm/fault.c:1539
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
Uninit was stored to memory at:
tcp_create_openreq_child+0x1984/0x1ff0 net/ipv4/tcp_minisocks.c:611
tcp_v4_syn_recv_sock+0x18e/0x2170 net/ipv4/tcp_ipv4.c:1754
tcp_check_req+0x1a3e/0x20c0 net/ipv4/tcp_minisocks.c:852
tcp_v4_rcv+0x26a4/0x53a0 net/ipv4/tcp_ipv4.c:2265
ip_protocol_deliver_rcu+0x884/0x1270 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x30f/0x530 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:314 [inline]
ip_local_deliver+0x230/0x4c0 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:460 [inline]
ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline]
ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline]
ip_sublist_rcv+0x10f7/0x13e0 net/ipv4/ip_input.c:639
ip_list_rcv+0x952/0x9c0 net/ipv4/ip_input.c:674
__netif_receive_skb_list_ptype net/core/dev.c:5703 [inline]
__netif_receive_skb_list_core+0xd92/0x11d0 net/core/dev.c:5751
__netif_receive_skb_list net/core/dev.c:5803 [inline]
netif_receive_skb_list_internal+0xd8f/0x1350 net/core/dev.c:5895
gro_normal_list include/net/gro.h:515 [inline]
napi_complete_done+0x3f2/0x990 net/core/dev.c:6246
e1000_clean+0x1fa4/0x5e50 drivers/net/ethernet/intel/e1000/e1000_main.c:3808
__napi_poll+0xd9/0x990 net/core/dev.c:6771
napi_poll net/core/dev.c:6840 [inline]
net_rx_action+0x90f/0x17e0 net/core/dev.c:6962
handle_softirqs+0x152/0x6b0 kernel/softirq.c:554
__do_softirq kernel/softirq.c:588 [inline]
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu kernel/softirq.c:637 [inline]
irq_exit_rcu+0x5d/0x120 kernel/softirq.c:649
common_interrupt+0x83/0x90 arch/x86/kernel/irq.c:278
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
Uninit was created at:
__alloc_pages_noprof+0x82d/0xcb0 mm/page_alloc.c:4706
__alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
alloc_slab_page mm/slub.c:2265 [inline]
allocate_slab mm/slub.c:2428 [inline]
new_slab+0x2af/0x14e0 mm/slub.c:2481
___slab_alloc+0xf73/0x3150 mm/slub.c:3667
__slab_alloc mm/slub.c:3757 [inline]
__slab_alloc_node mm/slub.c:3810 [inline]
slab_alloc_node mm/slub.c:3990 [inline]
kmem_cache_alloc_noprof+0x53a/0x9f0 mm/slub.c:4009
reqsk_alloc_noprof net/ipv4/inet_connection_sock.c:920 [inline]
inet_reqsk_alloc+0x63/0x700 net/ipv4/inet_connection_sock.c:951
tcp_conn_request+0x339/0x4860 net/ipv4/tcp_input.c:7177
tcp_v4_conn_request+0x13b/0x190 net/ipv4/tcp_ipv4.c:1719
tcp_rcv_state_process+0x2dd/0x4a10 net/ipv4/tcp_input.c:6711
tcp_v4_do_rcv+0xbee/0x10d0 net/ipv4/tcp_ipv4.c:1932
tcp_v4_rcv+0x3fad/0x53a0 net/ipv4/tcp_ipv4.c:2334
ip_protocol_deliver_rcu+0x884/0x1270 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x30f/0x530 net/ipv4/ip_input.c:233
NF_HOOK include/linux/netfilter.h:314 [inline]
ip_local_deliver+0x230/0x4c0 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:460 [inline]
ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline]
ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline]
ip_sublist_rcv+0x10f7/0x13e0 net/ipv4/ip_input.c:639
ip_list_rcv+0x952/0x9c0 net/ipv4/ip_input.c:674
__netif_receive_skb_list_ptype net/core/dev.c:5703 [inline]
__netif_receive_skb_list_core+0xd92/0x11d0 net/core/dev.c:5751
__netif_receive_skb_list net/core/dev.c:5803 [inline]
netif_receive_skb_list_internal+0xd8f/0x1350 net/core/dev.c:5895
gro_normal_list include/net/gro.h:515 [inline]
napi_complete_done+0x3f2/0x990 net/core/dev.c:6246
e1000_clean+0x1fa4/0x5e50 drivers/net/ethernet/intel/e1000/e1000_main.c:3808
__napi_poll+0xd9/0x990 net/core/dev.c:6771
napi_poll net/core/dev.c:6840 [inline]
net_rx_action+0x90f/0x17e0 net/core/dev.c:6962
handle_softirqs+0x152/0x6b0 kernel/softirq.c:554
__do_softirq kernel/softirq.c:588 [inline]
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu kernel/softirq.c:637 [inline]
irq_exit_rcu+0x5d/0x120 kernel/softirq.c:649
common_interrupt+0x83/0x90 arch/x86/kernel/irq.c:278
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
CPU: 0 PID: 239 Comm: modprobe Tainted: G B 6.10.0-rc7-01816-g852e42cc2dd4 #3 1107521f0c7b55c9309062382d0bda9f604dbb6d
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Fixes:
|
|
Florian Westphal
|
c75ad7c759 |
net: tcp: un-pin the tw_timer
After previous patch, even if timer fires immediately on another CPU, context that schedules the timer now holds the ehash spinlock, so timer cannot reap tw socket until ehash lock is released. BH disable is moved into hashdance_schedule. Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
|
Valentin Schneider
|
b334b924c9 |
net: tcp/dccp: prepare for tw_timer un-pinning
The TCP timewait timer is proving to be problematic for setups where scheduler CPU isolation is achieved at runtime via cpusets (as opposed to statically via isolcpus=domains). What happens there is a CPU goes through tcp_time_wait(), arming the time_wait timer, then gets isolated. TCP_TIMEWAIT_LEN later, the timer fires, causing interference for the now-isolated CPU. This is conceptually similar to the issue described in commit |
|
|
Eric Dumazet
|
69e0b33a7f |
tcp: annotate data-races around tw->tw_ts_recent and tw->tw_ts_recent_stamp
These fields can be read and written locklessly, add annotations around these minor races. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> |
|
|
Eric Dumazet
|
f4dca95fc0 |
tcp: reduce accepted window in NEW_SYN_RECV state
Jason commit made checks against ACK sequence less strict
and can be exploited by attackers to establish spoofed flows
with less probes.
Innocent users might use tcp_rmem[1] == 1,000,000,000,
or something more reasonable.
An attacker can use a regular TCP connection to learn the server
initial tp->rcv_wnd, and use it to optimize the attack.
If we make sure that only the announced window (smaller than 65535)
is used for ACK validation, we force an attacker to use
65537 packets to complete the 3WHS (assuming server ISN is unknown)
Fixes:
|
|
Jason Xing
|
11f46ea981 |
tcp: rstreason: fully support in tcp_check_req()
We're going to send an RST due to invalid syn packet which is already checked whether 1) it is in sequence, 2) it is a retransmitted skb. As RFC 793 says, if the state of socket is not CLOSED/LISTEN/SYN-SENT, then we should send an RST when receiving bad syn packet: "fourth, check the SYN bit,...If the SYN is in the window it is an error, send a reset" Signed-off-by: Jason Xing <kernelxing@tencent.com> Link: https://lore.kernel.org/r/20240510122502.27850-6-kerneljasonxing@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
|
|
Jason Xing
|
6be49deaa0 |
rstreason: prepare for passive reset
Adjust the parameter and support passing reason of reset which is for now NOT_SPECIFIED. No functional changes. Signed-off-by: Jason Xing <kernelxing@tencent.com> Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> |
|
|
Eric Dumazet
|
c51db4ac10 |
tcp: do not export tcp_twsk_purge()
After commit
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|
|
Eric Dumazet
|
41eecbd712 |
tcp: replace TCP_SKB_CB(skb)->tcp_tw_isn with a per-cpu field
TCP can transform a TIMEWAIT socket into a SYN_RECV one from
a SYN packet, and the ISN of the SYNACK packet is normally
generated using TIMEWAIT tw_snd_nxt :
tcp_timewait_state_process()
...
u32 isn = tcptw->tw_snd_nxt + 65535 + 2;
if (isn == 0)
isn++;
TCP_SKB_CB(skb)->tcp_tw_isn = isn;
return TCP_TW_SYN;
This SYN packet also bypasses normal checks against listen queue
being full or not.
tcp_conn_request()
...
__u32 isn = TCP_SKB_CB(skb)->tcp_tw_isn;
...
/* TW buckets are converted to open requests without
* limitations, they conserve resources and peer is
* evidently real one.
*/
if ((syncookies == 2 || inet_csk_reqsk_queue_is_full(sk)) && !isn) {
want_cookie = tcp_syn_flood_action(sk, rsk_ops->slab_name);
if (!want_cookie)
goto drop;
}
This was using TCP_SKB_CB(skb)->tcp_tw_isn field in skb.
Unfortunately this field has been accidentally cleared
after the call to tcp_timewait_state_process() returning
TCP_TW_SYN.
Using a field in TCP_SKB_CB(skb) for a temporary state
is overkill.
Switch instead to a per-cpu variable.
As a bonus, we do not have to clear tcp_tw_isn in TCP receive
fast path.
It is temporarily set then cleared only in the TCP_TW_SYN dance.
Fixes:
|
|
|
Eric Dumazet
|
1eeb504357 |
tcp/dccp: do not care about families in inet_twsk_purge()
We lost ability to unload ipv6 module a long time ago. Instead of calling expensive inet_twsk_purge() twice, we can handle all families in one round. Also remove an extra line added in my prior patch, per Kuniyuki Iwashima feedback. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/netdev/20240327192934.6843-1-kuniyu@amazon.com/ Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240329153203.345203-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
|
|
Kuniyuki Iwashima
|
2a750d6a5b |
rds: tcp: Fix use-after-free of net in reqsk_timer_handler().
syzkaller reported a warning of netns tracker [0] followed by KASAN
splat [1] and another ref tracker warning [1].
syzkaller could not find a repro, but in the log, the only suspicious
sequence was as follows:
18:26:22 executing program 1:
r0 = socket$inet6_mptcp(0xa, 0x1, 0x106)
...
connect$inet6(r0, &(0x7f0000000080)={0xa, 0x4001, 0x0, @loopback}, 0x1c) (async)
The notable thing here is 0x4001 in connect(), which is RDS_TCP_PORT.
So, the scenario would be:
1. unshare(CLONE_NEWNET) creates a per netns tcp listener in
rds_tcp_listen_init().
2. syz-executor connect()s to it and creates a reqsk.
3. syz-executor exit()s immediately.
4. netns is dismantled. [0]
5. reqsk timer is fired, and UAF happens while freeing reqsk. [1]
6. listener is freed after RCU grace period. [2]
Basically, reqsk assumes that the listener guarantees netns safety
until all reqsk timers are expired by holding the listener's refcount.
However, this was not the case for kernel sockets.
Commit
|
|
|
Jason Xing
|
b982569593 |
tcp: make the dropreason really work when calling tcp_rcv_state_process()
Update three callers including both ipv4 and ipv6 and let the dropreason mechanism work in reality. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
|
|
Dmitry Safonov
|
da7dfaa6d6 |
net/tcp: Consistently align TCP-AO option in the header
Currently functions that pre-calculate TCP header options length use
unaligned TCP-AO header + MAC-length for skb reservation.
And the functions that actually write TCP-AO options into skb do align
the header. Nothing good can come out of this for ((maclen % 4) != 0).
Provide tcp_ao_len_aligned() helper and use it everywhere for TCP
header options space calculations.
Fixes:
|
|
|
Dmitry Safonov
|
64382c71a5 |
net/tcp: Add TCP-AO SNE support
Add Sequence Number Extension (SNE) for TCP-AO. This is needed to protect long-living TCP-AO connections from replaying attacks after sequence number roll-over, see RFC5925 (6.2). Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> |
|
|
Dmitry Safonov
|
06b22ef295 |
net/tcp: Wire TCP-AO to request sockets
Now when the new request socket is created from the listening socket, it's recorded what MKT was used by the peer. tcp_rsk_used_ao() is a new helper for checking if TCP-AO option was used to create the request socket. tcp_ao_copy_all_matching() will copy all keys that match the peer on the request socket, as well as preparing them for the usage (creating traffic keys). Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> |
|
|
Dmitry Safonov
|
decde2586b |
net/tcp: Add TCP-AO sign to twsk
Add support for sockets in time-wait state. ao_info as well as all keys are inherited on transition to time-wait socket. The lifetime of ao_info is now protected by ref counter, so that tcp_ao_destroy_sock() will destruct it only when the last user is gone. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> |
|
|
Dmitry Safonov
|
8c73b26315 |
net/tcp: Prepare tcp_md5sig_pool for TCP-AO
TCP-AO, similarly to TCP-MD5, needs to allocate tfms on a slow-path,
which is setsockopt() and use crypto ahash requests on fast paths,
which are RX/TX softirqs. Also, it needs a temporary/scratch buffer
for preparing the hash.
Rework tcp_md5sig_pool in order to support other hashing algorithms
than MD5. It will make it possible to share pre-allocated crypto_ahash
descriptors and scratch area between all TCP hash users.
Internally tcp_sigpool calls crypto_clone_ahash() API over pre-allocated
crypto ahash tfm. Kudos to Herbert, who provided this new crypto API.
I was a little concerned over GFP_ATOMIC allocations of ahash and
crypto_request in RX/TX (see tcp_sigpool_start()), so I benchmarked both
"backends" with different algorithms, using patched version of iperf3[2].
On my laptop with i7-7600U @ 2.80GHz:
clone-tfm per-CPU-requests
TCP-MD5 2.25 Gbits/sec 2.30 Gbits/sec
TCP-AO(hmac(sha1)) 2.53 Gbits/sec 2.54 Gbits/sec
TCP-AO(hmac(sha512)) 1.67 Gbits/sec 1.64 Gbits/sec
TCP-AO(hmac(sha384)) 1.77 Gbits/sec 1.80 Gbits/sec
TCP-AO(hmac(sha224)) 1.29 Gbits/sec 1.30 Gbits/sec
TCP-AO(hmac(sha3-512)) 481 Mbits/sec 480 Mbits/sec
TCP-AO(hmac(md5)) 2.07 Gbits/sec 2.12 Gbits/sec
TCP-AO(hmac(rmd160)) 1.01 Gbits/sec 995 Mbits/sec
TCP-AO(cmac(aes128)) [not supporetd yet] 2.11 Gbits/sec
So, it seems that my concerns don't have strong grounds and per-CPU
crypto_request allocation can be dropped/removed from tcp_sigpool once
ciphers get crypto_clone_ahash() support.
[1]: https://lore.kernel.org/all/ZDefxOq6Ax0JeTRH@gondor.apana.org.au/T/#u
[2]: https://github.com/0x7f454c46/iperf/tree/tcp-md5-ao
Signed-off-by: Dmitry Safonov <dima@arista.com>
Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
Acked-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
|
Eric Dumazet
|
614e8316aa |
tcp: add support for usec resolution in TCP TS values
Back in 2015, Van Jacobson suggested to use usec resolution in TCP TS values. This has been implemented in our private kernels. Goals were : 1) better observability of delays in networking stacks. 2) better disambiguation of events based on TSval/ecr values. 3) building block for congestion control modules needing usec resolution. Back then we implemented a schem based on private SYN options to negotiate the feature. For upstream submission, we chose to use a route attribute, because this feature is probably going to be used in private networks [1] [2]. ip route add 10/8 ... features tcp_usec_ts Note that RFC 7323 recommends a "timestamp clock frequency in the range 1 ms to 1 sec per tick.", but also mentions "the maximum acceptable clock frequency is one tick every 59 ns." [1] Unfortunately RFC 7323 5.5 (Outdated Timestamps) suggests to invalidate TS.Recent values after a flow was idle for more than 24 days. This is the part making usec_ts a problem for peers following this recommendation for long living idle flows. [2] Attempts to standardize usec ts went nowhere: https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-tcp-options-for-low-latency-00.pdf https://datatracker.ietf.org/doc/draft-wang-tcpm-low-latency-opt/ Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
|
|
Eric Dumazet
|
2a7c8d291f |
tcp: introduce tcp_clock_ms()
It delivers current TCP time stamp in ms unit, and is used in place of confusing tcp_time_stamp_raw() It is the same family than tcp_clock_ns() and tcp_clock_ms(). tcp_time_stamp_raw() will be replaced later for TSval contexts with a more descriptive name. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
|
|
Eric Dumazet
|
10bbf1652c |
net: implement lockless SO_PRIORITY
This is a followup of
|
|
Aananth V
|
3868ab0f19 |
tcp: new TCP_INFO stats for RTO events
The 2023 SIGCOMM paper "Improving Network Availability with Protective
ReRoute" has indicated Linux TCP's RTO-triggered txhash rehashing can
effectively reduce application disruption during outages. To better
measure the efficacy of this feature, this patch adds three more
detailed stats during RTO recovery and exports via TCP_INFO.
Applications and monitoring systems can leverage this data to measure
the network path diversity and end-to-end repair latency during network
outages to improve their network infrastructure.
The following counters are added to tcp_sock in order to track RTO
events over the lifetime of a TCP socket.
1. u16 total_rto - Counts the total number of RTO timeouts.
2. u16 total_rto_recoveries - Counts the total number of RTO recoveries.
3. u32 total_rto_time - Counts the total time spent (ms) in RTO
recoveries. (time spent in CA_Loss and
CA_Recovery states)
To compute total_rto_time, we add a new u32 rto_stamp field to
tcp_sock. rto_stamp records the start timestamp (ms) of the last RTO
recovery (CA_Loss).
Corresponding fields are also added to the tcp_info struct.
Signed-off-by: Aananth V <aananthv@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|