From nobody Mon Nov 10 19:55:44 2025 X-Original-To: dev-commits-src-branches@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4d50lN5MQrz63LWX; Mon, 10 Nov 2025 19:55:44 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R12" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4d50lN4dfsz3Yth; Mon, 10 Nov 2025 19:55:44 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1762804544; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=OxFAp+1gRnJiAhmCZjWn+heV+WPDHWlxVcIS8rY+4sM=; b=nHy1IkAX5P7r1cgGwp1YJqHm5BieYZMugEAgeXz9qoFShFfIbfCwbdMixldH4cc9Imp5XR 5C6trRWhWW5ISFOaRKQQGSiNU/aODFCA1FBBHi80MM3aMXvB7X+s6SdI+TCEVSgC6if968 bQnok2suUpOpF9KNrYUFqUps9CaMZVWFf5Clv1Z7buLUSZ/qhl34hKOUu6+I3AB/WPFuaF FnVUYWs1mVMeEGETyZdP/hrN4NZkBWuXHYnz5SrddOJidugorT6oLjd21cX96IE/pn0mpa UfwoywlPms4aSYokO3RyeM3KswHJb7N/FGiehQQw0HyIjXbrkfr+LmZjf4ODDg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1762804544; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=OxFAp+1gRnJiAhmCZjWn+heV+WPDHWlxVcIS8rY+4sM=; b=t3pbLY1MS2TtfbUDaH5QcaPXWPGp2JLYQDeF/mlctPFTSnEmB4Cy77BakWYNUGDEplY1xP V13bgb5yNs+nqEH+iIT1okNxtAIQVS7jMRCfrrkE0fEJg7SuWPJupM4xteMF6V5TtHyV75 ekw6GPMDyBzeBjl2+4kxXqakfGK/C9LfepIMk833wMracLe6JK0bCLHxbMvrsyh1+aM5/U FHJI0hPNsQ3gMUGbm2GcNTJ2erV8jbI0OiyAivQsY61OUBf6s+yPwlhtXmXaOT5WvZTjLD lDz5CshD/xu6fl3Z+xWiPsQhTHrYE20Wgp9SuFhOzlrsBfBaYszEsFnHne6+pA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1762804544; a=rsa-sha256; cv=none; b=xg/eTJC07bQrpEYpcV1lvo7NMW+jNQuntM93nl4slD5T46xQK66WuL586HNhbcakehCWzf YrTvMw6Cagw3u0GMIC/SfgxDyKeP3Ikpqz++is563ByugdqBU5ctF59u1AdF5JcO7VW7ts vfsbSd2hMeRoM1ICKIUlJ3BKctVJjd/YsEPHWGHPlNf0NN6AnIeBAzQzGXOXNnwkexxjsa whGoiHqEdR9Mc9I6TeItATryumKgDG6DXgKLt5FDea0aqJY7WFVHFR/huRTVXp3vN3tlQO VDs+0LXdnQ5biV4JmETmAwMd6JaSn8HzkkTqNelWGPnuJKFYD7YtDYb2Wgivow== ARC-Authentication-Results: i=1; mx1.freebsd.org; none Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4d50lN4138zXYB; Mon, 10 Nov 2025 19:55:44 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 5AAJtir5008281; Mon, 10 Nov 2025 19:55:44 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 5AAJtie3008278; Mon, 10 Nov 2025 19:55:44 GMT (envelope-from git) Date: Mon, 10 Nov 2025 19:55:44 GMT Message-Id: <202511101955.5AAJtie3008278@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Michael Tuexen Subject: git: e082156ae14b - stable/15 - tcp: drop SYN ACK segment for listening sockets List-Id: Commits to the stable branches of the FreeBSD src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-branches List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-branches@freebsd.org Sender: owner-dev-commits-src-branches@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: tuexen X-Git-Repository: src X-Git-Refname: refs/heads/stable/15 X-Git-Reftype: branch X-Git-Commit: e082156ae14b6717f08dccfff62d1fcbb3b26487 Auto-Submitted: auto-generated The branch stable/15 has been updated by tuexen: URL: https://cgit.FreeBSD.org/src/commit/?id=e082156ae14b6717f08dccfff62d1fcbb3b26487 commit e082156ae14b6717f08dccfff62d1fcbb3b26487 Author: Michael Tuexen AuthorDate: 2025-11-03 10:50:49 +0000 Commit: Michael Tuexen CommitDate: 2025-11-10 19:52:56 +0000 tcp: drop SYN ACK segment for listening sockets When a SYN ACK is received for a listening socket, just drop it instead of killing the SYN-cache entry and send a RST. This closes the possibility to kill a TCP connection during its handling in the SYN-cache. Reviewed by: Nick Banks, Peter Lei Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D53540 (cherry picked from commit 239464e99321ede07664782426ec4e54cd8a618d) --- sys/netinet/tcp_input.c | 5 ++--- sys/netinet/tcp_syncache.c | 17 ----------------- sys/netinet/tcp_syncache.h | 1 - 3 files changed, 2 insertions(+), 21 deletions(-) diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c index 2146b0cac48f..9c58c2815d13 100644 --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -1192,11 +1192,10 @@ tfo_socket_result: if (thflags & TH_ACK) { if ((s = tcp_log_addrs(&inc, th, NULL, NULL))) log(LOG_DEBUG, "%s; %s: Listen socket: " - "SYN|ACK invalid, segment rejected\n", + "SYN|ACK invalid, segment ignored\n", s, __func__); - syncache_badack(&inc, port); /* XXX: Not needed! */ TCPSTAT_INC(tcps_badsyn); - goto dropwithreset; + goto dropunlock; } /* * If the drop_synfin option is enabled, drop all diff --git a/sys/netinet/tcp_syncache.c b/sys/netinet/tcp_syncache.c index 3a7755e9f09e..fa7035771714 100644 --- a/sys/netinet/tcp_syncache.c +++ b/sys/netinet/tcp_syncache.c @@ -712,23 +712,6 @@ done: SCH_UNLOCK(sch); } -void -syncache_badack(struct in_conninfo *inc, uint16_t port) -{ - struct syncache *sc; - struct syncache_head *sch; - - if (syncache_cookiesonly()) - return; - sc = syncache_lookup(inc, &sch); /* returns locked sch */ - SCH_LOCK_ASSERT(sch); - if ((sc != NULL) && (sc->sc_port == port)) { - syncache_drop(sc, sch); - TCPSTAT_INC(tcps_sc_badack); - } - SCH_UNLOCK(sch); -} - void syncache_unreach(struct in_conninfo *inc, tcp_seq th_seq, uint16_t port) { diff --git a/sys/netinet/tcp_syncache.h b/sys/netinet/tcp_syncache.h index 37f6ff3d6ca9..c916b4de6ae0 100644 --- a/sys/netinet/tcp_syncache.h +++ b/sys/netinet/tcp_syncache.h @@ -45,7 +45,6 @@ struct socket * syncache_add(struct in_conninfo *, struct tcpopt *, void *, void *, uint8_t, uint16_t); void syncache_chkrst(struct in_conninfo *, struct tcphdr *, struct mbuf *, uint16_t); -void syncache_badack(struct in_conninfo *, uint16_t); int syncache_pcblist(struct sysctl_req *); struct syncache {