From nobody Mon Nov 10 19:55:48 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 4d50lS3848z63Lfr; Mon, 10 Nov 2025 19:55:48 +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 4d50lS2KfJz3Z7V; Mon, 10 Nov 2025 19:55:48 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1762804548; 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=x4lRBLtgrqlOVk8X8fsO9FZ2+kMe3Ed4dt8C4zKOOHo=; b=PIcenYR72Op8lsvRSsRtcOVIOtd5/Q5i4tk6l3v3PUROqzWGgCPbhJqdEhpkmDkWMwhJhL fPkDEYXFJnIj2bK7gzZRj3NVR3EEm0CSUg5P/Vl8qRioEKXD0eWw/6SG7eFPQxstKYz+8z CEik9xaTLD+0OLyxC4xvGLkM9f0JK+r0vu8z5YJmtGIX24MAYvGlTU2laSAEb70RNK8P30 MDlGa1j7GYpljbe8DM+OYGDsWklPBCdQ9rK/8RDNtMs5rP+d/Q4DF/wApRVZJMLY6kZmJS ElsHI3uPti5Dg5fMBkELcbg/a4Hra6WLemY9h8dNCkPK4uDGvIe3/OgGV1n8Bw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1762804548; 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=x4lRBLtgrqlOVk8X8fsO9FZ2+kMe3Ed4dt8C4zKOOHo=; b=nPVEn4VijXKafS09Vs1Pq//qgAZEVWgYxQSq4n0YC/xgpowYtcbczYXf2l1NCrNsNq+yv4 qg/oi2FdOQfek4OwDNXF6GtQt+Wgcoo7Jpr4F8dDavY3q1RKggbys9uxOn7OUoPex199hu IgHYRjGK5Ltd3yLw/KsTWLFkeYM7bhHQ/Bl2IQ+U324PeJw/fxyDcATHJ7RRy/pmF9emEd 5xwOkOBG19XRsGljqbdGQUZuslVUyRCzT+QhKxC4na2rQgAyoWu4Q8WE9X5kZBBypSFqVc O+Bz+o2sbU0hWHUemnLpNaejzvy+nNCK3jlxEjVNMJrRQKXsgGxhRWhlMkMDCw== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1762804548; a=rsa-sha256; cv=none; b=SvjmkhQsFMzMj+agksMcWVrXuPPsVaOLtElEJb4oLA3VzKv822GMDTwoe5dJgomfDjp47N 1AYXte18hjKzC+WXNuLZXTjpYOuV0NzxjgyW33iNi9VRvmQbidoeIsjAnDcse+4W/iLY8J rG6aEFyDimM3Xe+4cfffPoLfUyN5XIdpmkPJxlh49tCZJsPubFKDU6t3m9VkPBoAhZaIDX rB8dc/+7iKml9F/QaWC6AuyGAZPYW4PFFQ12cZQqaEXvnNd/7imAJ/4BzaE6e+OB2BgNcz 1ZDwrZDIlj0DAg6Xy7f6KBmizx7iQurTqIRBk7vVjoWRwxyAn8QWmO/kizfRyA== 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 4d50lS1XlQzXMb; Mon, 10 Nov 2025 19:55:48 +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 5AAJtmGI008451; Mon, 10 Nov 2025 19:55:48 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 5AAJtmI3008448; Mon, 10 Nov 2025 19:55:48 GMT (envelope-from git) Date: Mon, 10 Nov 2025 19:55:48 GMT Message-Id: <202511101955.5AAJtmI3008448@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: b1ed408e0346 - stable/14 - 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/14 X-Git-Reftype: branch X-Git-Commit: b1ed408e034655e89be91d91d5677f7e90224024 Auto-Submitted: auto-generated The branch stable/14 has been updated by tuexen: URL: https://cgit.FreeBSD.org/src/commit/?id=b1ed408e034655e89be91d91d5677f7e90224024 commit b1ed408e034655e89be91d91d5677f7e90224024 Author: Michael Tuexen AuthorDate: 2025-11-03 10:50:49 +0000 Commit: Michael Tuexen CommitDate: 2025-11-10 19:53:28 +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 4a6f8d80f231..9dfd38d679e9 100644 --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -1209,11 +1209,10 @@ 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 713f6a35ad45..376a5d958504 100644 --- a/sys/netinet/tcp_syncache.c +++ b/sys/netinet/tcp_syncache.c @@ -720,23 +720,6 @@ 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 9445940bcec5..b188e6ad2ab6 100644 --- a/sys/netinet/tcp_syncache.h +++ b/sys/netinet/tcp_syncache.h @@ -47,7 +47,6 @@ 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 {