kernel/linux.git/net/ipv4/tcp_timer.c, branch v7.1-rc5

tcp: make probe0 timer handle expired user timeout

2026-04-28T02:16:07+00:00

tcp_clamp_probe0_to_user_timeout() computes remaining time in jiffies using subtraction with an unsigned lvalue. If elapsed probing time exceeds the configured TCP_USER_TIMEOUT, the underflow yields a large value. This ends up re-arming the probe timer for a full backoff interval instead of expiring immediately, delaying connection teardown beyond the configured timeout. Fix this by preventing underflow so user-set timeout expiration is handled correctly without extending the probe timer. Fixes: 344db93ae3ee ("tcp: make TCP_USER_TIMEOUT accurate for zero window probes") Link: https://lore.kernel.org/r/20260414013634.43997-1-ahacigu.linux@gmail.com Signed-off-by: Altan Hacigumus Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260424014639.54110-1-ahacigu.linux@gmail.com Signed-off-by: Jakub Kicinski

tcp: annotate data-races around tp->timeout_rehash

2026-04-18T18:10:13+00:00

tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: 32efcc06d2a1 ("tcp: export count for rehash attempts") Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20260416200319.3608680-13-edumazet@google.com Signed-off-by: Jakub Kicinski

net: remove EXPORT_IPV6_MOD() and EXPORT_IPV6_MOD_GPL() macros

2026-03-29T18:21:22+00:00

As IPv6 is built-in only, the macro is always evaluating to an empty one. Remove it completely from the code. Signed-off-by: Fernando Fernandez Mancera Link: https://patch.msgid.link/20260325120928.15848-3-fmancera@suse.de Signed-off-by: Jakub Kicinski

tcp: accecn: unset ECT if receive or send ACE=0 in AccECN negotiaion

2026-02-03T14:13:24+00:00

Based on specification: https://tools.ietf.org/id/draft-ietf-tcpm-accurate-ecn-28.txt Based on Section 3.1.5 of AccECN spec (RFC9768), a TCP Server in AccECN mode MUST NOT set ECT on any packet for the rest of the connection, if it has received or sent at least one valid SYN or Acceptable SYN/ACK with (AE,CWR,ECE) = (0,0,0) during the handshake. In addition, a host in AccECN mode that is feeding back the IP-ECN field on a SYN or SYN/ACK MUST feed back the IP-ECN field on the latest valid SYN or acceptable SYN/ACK to arrive. Signed-off-by: Chia-Yu Chang Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260131222515.8485-11-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni

tcp: remove icsk->icsk_retransmit_timer

2025-11-26T03:28:29+00:00

Now sk->sk_timer is no longer used by TCP keepalive, we can use its storage for TCP and MPTCP retransmit timers for better cache locality. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20251124175013.1473655-5-edumazet@google.com Signed-off-by: Jakub Kicinski

tcp: introduce icsk->icsk_keepalive_timer

2025-11-26T03:28:29+00:00

sk->sk_timer has been used for TCP keepalives. Keepalive timers are not in fast path, we want to use sk->sk_timer storage for retransmit timers, for better cache locality. Create icsk->icsk_keepalive_timer and change keepalive code to no longer use sk->sk_timer. Added space is reclaimed in the following patch. This includes changes to MPTCP, which was also using sk_timer. Alias icsk->mptcp_tout_timer and icsk->icsk_keepalive_timer for inet_sk_diag_fill() sake. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20251124175013.1473655-4-edumazet@google.com Signed-off-by: Jakub Kicinski

tcp: rename icsk_timeout() to tcp_timeout_expires()

2025-11-26T03:28:28+00:00

In preparation of sk->tcp_timeout_timer introduction, rename icsk_timeout() helper and change its argument to plain 'const struct sock *sk'. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20251124175013.1473655-2-edumazet@google.com Signed-off-by: Jakub Kicinski

tcp: Call tcp_syn_ack_timeout() directly.

2025-11-08T02:05:25+00:00

Since DCCP has been removed, we do not need to use request_sock_ops.syn_ack_timeout(). Let's call tcp_syn_ack_timeout() directly. Now other function pointers of request_sock_ops are protocol-dependent. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20251106003357.273403-2-kuniyu@google.com Signed-off-by: Jakub Kicinski

tcp: annotate data-races around icsk->icsk_probes_out

2025-08-25T23:20:59+00:00

icsk->icsk_probes_out is read locklessly from inet_sk_diag_fill(), get_tcp4_sock() and get_tcp6_sock(). Add corresponding READ_ONCE()/WRITE_ONCE() annotations. Signed-off-by: Eric Dumazet Reviewed-by: Neal Cardwell Link: https://patch.msgid.link/20250822091727.835869-3-edumazet@google.com Signed-off-by: Jakub Kicinski

tcp: annotate data-races around icsk->icsk_retransmits

2025-08-25T23:20:59+00:00

icsk->icsk_retransmits is read locklessly from inet_sk_diag_fill(), tcp_get_timestamping_opt_stats, get_tcp4_sock() and get_tcp6_sock(). Add corresponding READ_ONCE()/WRITE_ONCE() annotations. Signed-off-by: Eric Dumazet Reviewed-by: Neal Cardwell Link: https://patch.msgid.link/20250822091727.835869-2-edumazet@google.com Signed-off-by: Jakub Kicinski