From owner-svn-src-stable@freebsd.org Thu Oct 3 10:44:10 2019 Return-Path: Delivered-To: svn-src-stable@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 6F6DF130DFC; Thu, 3 Oct 2019 10:44:10 +0000 (UTC) (envelope-from tuexen@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) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 46kV4B2Hm4z3RJd; Thu, 3 Oct 2019 10:44:10 +0000 (UTC) (envelope-from tuexen@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 32072ADC3; Thu, 3 Oct 2019 10:44:10 +0000 (UTC) (envelope-from tuexen@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x93AiATk010525; Thu, 3 Oct 2019 10:44:10 GMT (envelope-from tuexen@FreeBSD.org) Received: (from tuexen@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x93Ai98N010524; Thu, 3 Oct 2019 10:44:09 GMT (envelope-from tuexen@FreeBSD.org) Message-Id: <201910031044.x93Ai98N010524@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: tuexen set sender to tuexen@FreeBSD.org using -f From: Michael Tuexen Date: Thu, 3 Oct 2019 10:44:09 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r353035 - in stable/12/sys/netinet: . tcp_stacks X-SVN-Group: stable-12 X-SVN-Commit-Author: tuexen X-SVN-Commit-Paths: in stable/12/sys/netinet: . tcp_stacks X-SVN-Commit-Revision: 353035 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-stable@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for all the -stable branches of the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 03 Oct 2019 10:44:10 -0000 Author: tuexen Date: Thu Oct 3 10:44:09 2019 New Revision: 353035 URL: https://svnweb.freebsd.org/changeset/base/353035 Log: MFC r352868: RFC 7112 requires a host to put the complete IP header chain including the TCP header in the first IP packet. Enforce this in tcp_output(). In addition make sure that at least one byte payload fits in the TCP segement to allow making progress. Without this check, a kernel with INVARIANTS will panic. This issue was found by running an instance of syzkaller. Manually resolved a conflict, since we don't have BBR in stable/12. Reviewed by: jtl@ Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D21665 Modified: stable/12/sys/netinet/tcp_output.c stable/12/sys/netinet/tcp_stacks/rack.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/netinet/tcp_output.c ============================================================================== --- stable/12/sys/netinet/tcp_output.c Thu Oct 3 10:37:53 2019 (r353034) +++ stable/12/sys/netinet/tcp_output.c Thu Oct 3 10:44:09 2019 (r353035) @@ -931,6 +931,20 @@ send: if (tp->t_flags & TF_NEEDFIN) sendalot = 1; } else { + if (optlen + ipoptlen >= tp->t_maxseg) { + /* + * Since we don't have enough space to put + * the IP header chain and the TCP header in + * one packet as required by RFC 7112, don't + * send it. Also ensure that at least one + * byte of the payload can be put into the + * TCP segment. + */ + SOCKBUF_UNLOCK(&so->so_snd); + error = EMSGSIZE; + sack_rxmit = 0; + goto out; + } len = tp->t_maxseg - optlen - ipoptlen; sendalot = 1; if (dont_sendalot) Modified: stable/12/sys/netinet/tcp_stacks/rack.c ============================================================================== --- stable/12/sys/netinet/tcp_stacks/rack.c Thu Oct 3 10:37:53 2019 (r353034) +++ stable/12/sys/netinet/tcp_stacks/rack.c Thu Oct 3 10:44:09 2019 (r353035) @@ -7954,12 +7954,14 @@ send: sendalot = 1; } else { - if (optlen + ipoptlen > tp->t_maxseg) { + if (optlen + ipoptlen >= tp->t_maxseg) { /* * Since we don't have enough space to put * the IP header chain and the TCP header in * one packet as required by RFC 7112, don't - * send it. + * send it. Also ensure that at least one + * byte of the payload can be put into the + * TCP segment. */ SOCKBUF_UNLOCK(&so->so_snd); error = EMSGSIZE;