kernel/linux.git/include/net/tcp.h, branch v6.19.11

tcp: secure_seq: add back ports to TS offset

2026-03-12T11:09:56+00:00

[ Upstream commit 165573e41f2f66ef98940cf65f838b2cb575d9d1 ] This reverts 28ee1b746f49 ("secure_seq: downgrade to per-host timestamp offsets") tcp_tw_recycle went away in 2017. Zhouyan Deng reported off-path TCP source port leakage via SYN cookie side-channel that can be fixed in multiple ways. One of them is to bring back TCP ports in TS offset randomization. As a bonus, we perform a single siphash() computation to provide both an ISN and a TS offset. Fixes: 28ee1b746f49 ("secure_seq: downgrade to per-host timestamp offsets") Reported-by: Zhouyan Deng Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Acked-by: Florian Westphal Link: https://patch.msgid.link/20260302205527.1982836-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

tcp: fix potential race in tcp_v6_syn_recv_sock()

2026-03-04T12:20:51+00:00

[ Upstream commit 858d2a4f67ff69e645a43487ef7ea7f28f06deae ] Code in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock() is done too late. After tcp_v4_syn_recv_sock(), the child socket is already visible from TCP ehash table and other cpus might use it. Since newinet->pinet6 is still pointing to the listener ipv6_pinfo bad things can happen as syzbot found. Move the problematic code in tcp_v6_mapped_child_init() and call this new helper from tcp_v4_syn_recv_sock() before the ehash insertion. This allows the removal of one tcp_sync_mss(), since tcp_v4_syn_recv_sock() will call it with the correct context. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+937b5bbb6a815b3e5d0b@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/69949275.050a0220.2eeac1.0145.GAE@google.com/ Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260217161205.2079883-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

tcp: disable RFC3168 fallback identifier for CC modules

2026-02-26T23:01:10+00:00

[ Upstream commit e68c28f22f46ecfdec3656ae785dd8ccbb4d557d ] When AccECN is not successfully negociated for a TCP flow, it defaults fallback to classic ECN (RFC3168). However, L4S service will fallback to non-ECN. This patch enables congestion control module to control whether it should not fallback to classic ECN after unsuccessful AccECN negotiation. A new CA module flag (TCP_CONG_NO_FALLBACK_RFC3168) identifies this behavior expected by the CA. Signed-off-by: Chia-Yu Chang Acked-by: Paolo Abeni Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260131222515.8485-6-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni Stable-dep-of: c5ff6b837159 ("tcp: accecn: handle unexpected AccECN negotiation feedback") Signed-off-by: Sasha Levin

tcp: ECT_1_NEGOTIATION and NEEDS_ACCECN identifiers

2026-02-26T23:01:10+00:00

[ Upstream commit 100f946b8d44b64bc0b8a8c30d283105031c0a77 ] Two flags for congestion control (CC) module are added in this patch related to AccECN negotiation. First, a new flag (TCP_CONG_NEEDS_ACCECN) defines that the CC expects to negotiate AccECN functionality using the ECE, CWR and AE flags in the TCP header. Second, during ECN negotiation, ECT(0) in the IP header is used. This patch enables CC to control whether ECT(0) or ECT(1) should be used on a per-segment basis. A new flag (TCP_CONG_ECT_1_NEGOTIATION) defines the expected ECT value in the IP header by the CA when not-yet initialized for the connection. The detailed AccECN negotiaotn can be found in IETF RFC9768. Co-developed-by: Olivier Tilmans Signed-off-by: Olivier Tilmans Signed-off-by: Ilpo Järvinen Signed-off-by: Chia-Yu Chang Acked-by: Paolo Abeni Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260131222515.8485-5-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni Stable-dep-of: c5ff6b837159 ("tcp: accecn: handle unexpected AccECN negotiation feedback") Signed-off-by: Sasha Levin

tcp: gro: inline tcp_gro_pull_header()

2025-11-15T02:00:08+00:00

tcp_gro_pull_header() is used in GRO fast path, inline it. Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20251113140358.58242-1-edumazet@google.com Signed-off-by: Jakub Kicinski

tcp: Apply max RTO to non-TFO SYN+ACK.

2025-11-08T02:05:26+00:00

Since commit 54a378f43425 ("tcp: add the ability to control max RTO"), TFO SYN+ACK RTO is capped by the TFO full sk's inet_csk(sk)->icsk_rto_max. The value is inherited from the parent listener. Let's apply the same cap to non-TFO SYN+ACK. Note that req->rsk_listener is always non-NULL when we call tcp_reqsk_timeout() in reqsk_timer_handler() or tcp_check_req(). It could be NULL for SYN cookie req, but we do not use req->timeout then. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20251106003357.273403-6-kuniyu@google.com Signed-off-by: Jakub Kicinski

tcp: Remove timeout arg from reqsk_timeout().

2025-11-08T02:05:26+00:00

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 Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20251106003357.273403-5-kuniyu@google.com Signed-off-by: Jakub Kicinski

net: Convert proto callbacks from sockaddr to sockaddr_unsized

2025-11-05T03:10:33+00:00

Convert struct proto pre_connect(), connect(), bind(), and bind_add() callback function prototypes from struct sockaddr to struct sockaddr_unsized. This does not change per-implementation use of sockaddr for passing around an arbitrarily sized sockaddr struct. Those will be addressed in future patches. Additionally removes the no longer referenced struct sockaddr from include/net/inet_common.h. No binary changes expected. Signed-off-by: Kees Cook Link: https://patch.msgid.link/20251104002617.2752303-5-kees@kernel.org Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2025-10-31T13:46:03+00:00

Cross-merge networking fixes after downstream PR (net-6.18-rc4). No conflicts, adjacent changes: drivers/net/ethernet/stmicro/stmmac/stmmac_main.c ded9813d17d3 ("net: stmmac: Consider Tx VLAN offload tag length for maxSDU") 26ab9830beab ("net: stmmac: replace has_xxxx with core_type") Signed-off-by: Jakub Kicinski

tcp: add newval parameter to tcp_rcvbuf_grow()

2025-10-30T00:30:19+00:00

This patch has no functional change, and prepares the following one. tcp_rcvbuf_grow() will need to have access to tp->rcvq_space.space old and new values. Change mptcp_rcvbuf_grow() in a similar way. Signed-off-by: Eric Dumazet [ Moved 'oldval' declaration to the next patch to avoid warnings at build time. ] Signed-off-by: Matthieu Baerts (NGI0) Reviewed-by: Neal Cardwell Link: https://patch.msgid.link/20251028-net-tcp-recv-autotune-v3-3-74b43ba4c84c@kernel.org Signed-off-by: Jakub Kicinski