From nobody Mon Nov 03 14:53:40 2025 X-Original-To: dev-commits-src-all@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 4d0ZN527Qtz6515m; Mon, 03 Nov 2025 14:53:41 +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 4d0ZN45JNKz3WCB; Mon, 03 Nov 2025 14:53:40 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1762181620; 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=91g6RvfuHJsMb9ZW3ijKiGdji5BA/9rEG3fWcemmJDU=; b=J4geVyuqmc+Cfd67j2m3WPkZC+Y4XoUJHSjACnqELTDcZ8/Qm+YUi9zI2eADeUnign3iAj YDErdffb/N9yyq0C6zSeGEX1l8+JYzkuKaSZYCxNUYQutNNrCHsqZuLeK+NDmtJW1iwEUE 4UYyDD04RGtwxD2BT+hmxLZtgk5qZm7zIBAlCnd7+4HvjqF6wJsyWfdgZ5OB35KT7Jhttb p4SlyTdjVvaGl8odJv1yQlhETc3ghuCgjmHcP+vXGoRD3WeB58+SboixM/+uL9Texfw+6A 5rM4eXrak1dh4RCPRe5SpErz6eSTnxa6q7+6L976y69dyIxlc5MYRHX6Te2ozA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1762181620; 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=91g6RvfuHJsMb9ZW3ijKiGdji5BA/9rEG3fWcemmJDU=; b=CY84ecFPW3AsKZXtA0q2G+MehpG0oieQ2rXgEckCugWg9Z8bzeEMinho3aAbYUt0EnWfUC vMEdEP1NHj9X7chPkLD4xIOWg42t9CK5Jwe+FSYN58SsHFWZyS9RZ1RkIYaZPZM7lZcNae EpTiPWTXq66tpG82jTG56L1S8k+vKjtKYH8R+6aqOE8GFrbP1yGAgYIpaU5TucUQAdT7OF Z/jsKr5Neln1A2fqJIzJ9PIZM6KNuZqdr2NizE2soDYfgvUXiAaVa/ZuVKSeax5VY3Fh5u EcgF3A/cO4GFVi3PkMa2PAMWFNwmH6uKNihcXRXJo0zVxPOOQdpteNrfe5/teg== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1762181620; a=rsa-sha256; cv=none; b=XAtPKWz5fo+qiIOa64sEO0+G37owg3qWjveit8aL+fKddG3Y7NIUtBSiDtCN2EJd5eC8mF Vs8AdW3xG+P30sf9u/g9ixPJ0Kj+nA/lizEQojmR6gFWNTGsEIwupxW/F0qn2158TfL0Uq G2eRiFYKt0mbFpiFp14p8jXcBgjDLjOOma1SZoTsf4mjvW5OlAZoR2IV97TjBV25F2pcun QiNCcl3WzvWl0p61LrwPE42oqJ/uk34fj7Qs0nHPTyTVC7AAOtWE22A/b1sYN8UkcP9csq sGZykxDU8/BPBDBo+2gbTPx1Gfa3Zsa2W/oZy1cMSNuOj2tjcGPHytx+MgSZ8Q== 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 4d0ZN44jwQz1TJ; Mon, 03 Nov 2025 14:53:40 +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 5A3EreAu027607; Mon, 3 Nov 2025 14:53:40 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 5A3EreKP027604; Mon, 3 Nov 2025 14:53:40 GMT (envelope-from git) Date: Mon, 3 Nov 2025 14:53:40 GMT Message-Id: <202511031453.5A3EreKP027604@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Michael Tuexen Subject: git: 239464e99321 - main - tcp: drop SYN ACK segment for listening sockets List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@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/main X-Git-Reftype: branch X-Git-Commit: 239464e99321ede07664782426ec4e54cd8a618d Auto-Submitted: auto-generated The branch main has been updated by tuexen: URL: https://cgit.FreeBSD.org/src/commit/?id=239464e99321ede07664782426ec4e54cd8a618d commit 239464e99321ede07664782426ec4e54cd8a618d Author: Michael Tuexen AuthorDate: 2025-11-03 10:50:49 +0000 Commit: Michael Tuexen CommitDate: 2025-11-03 10:50:49 +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 MFC after: 3 days Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D53540 --- 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 {