From owner-svn-src-all@freebsd.org Thu May 7 01:37:43 2020 Return-Path: Delivered-To: svn-src-all@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 89DEF2E6979; Thu, 7 May 2020 01:37:43 +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 49HbgW3760z4XKB; Thu, 7 May 2020 01:37:43 +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 66A348E3E; Thu, 7 May 2020 01:37:43 +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 0471bhcv061499; Thu, 7 May 2020 01:37:43 GMT (envelope-from tuexen@FreeBSD.org) Received: (from tuexen@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 0471bhIO061498; Thu, 7 May 2020 01:37:43 GMT (envelope-from tuexen@FreeBSD.org) Message-Id: <202005070137.0471bhIO061498@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: tuexen set sender to tuexen@FreeBSD.org using -f From: Michael Tuexen Date: Thu, 7 May 2020 01:37:43 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r360736 - stable/11/sys/netinet X-SVN-Group: stable-11 X-SVN-Commit-Author: tuexen X-SVN-Commit-Paths: stable/11/sys/netinet X-SVN-Commit-Revision: 360736 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 May 2020 01:37:43 -0000 Author: tuexen Date: Thu May 7 01:37:42 2020 New Revision: 360736 URL: https://svnweb.freebsd.org/changeset/base/360736 Log: MFC r352594: Improve SCTP locking Don't hold the info lock when calling sctp_select_a_tag(). This avoids a double lock bug in the NAT colliding state processing of SCTP. Thanks to Felix Weinrank for finding and reporting this issue in https://github.com/sctplab/usrsctp/issues/374 He found this bug using fuzz testing. Modified: stable/11/sys/netinet/sctp_input.c Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/netinet/sctp_input.c ============================================================================== --- stable/11/sys/netinet/sctp_input.c Thu May 7 01:34:41 2020 (r360735) +++ stable/11/sys/netinet/sctp_input.c Thu May 7 01:37:42 2020 (r360736) @@ -702,34 +702,37 @@ static int sctp_handle_nat_colliding_state(struct sctp_tcb *stcb) { /* - * return 0 means we want you to proceed with the abort non-zero - * means no abort processing + * Return 0 means we want you to proceed with the abort non-zero + * means no abort processing. */ + uint32_t new_vtag; struct sctpasochead *head; if ((SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_WAIT) || (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_ECHOED)) { + new_vtag = sctp_select_a_tag(stcb->sctp_ep, stcb->sctp_ep->sctp_lport, stcb->rport, 1); atomic_add_int(&stcb->asoc.refcnt, 1); SCTP_TCB_UNLOCK(stcb); SCTP_INP_INFO_WLOCK(); SCTP_TCB_LOCK(stcb); atomic_subtract_int(&stcb->asoc.refcnt, 1); + } else { + return (0); } if (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_WAIT) { /* generate a new vtag and send init */ LIST_REMOVE(stcb, sctp_asocs); - stcb->asoc.my_vtag = sctp_select_a_tag(stcb->sctp_ep, stcb->sctp_ep->sctp_lport, stcb->rport, 1); + stcb->asoc.my_vtag = new_vtag; head = &SCTP_BASE_INFO(sctp_asochash)[SCTP_PCBHASH_ASOC(stcb->asoc.my_vtag, SCTP_BASE_INFO(hashasocmark))]; /* * put it in the bucket in the vtag hash of assoc's for the * system */ LIST_INSERT_HEAD(head, stcb, sctp_asocs); - sctp_send_initiate(stcb->sctp_ep, stcb, SCTP_SO_NOT_LOCKED); SCTP_INP_INFO_WUNLOCK(); + sctp_send_initiate(stcb->sctp_ep, stcb, SCTP_SO_NOT_LOCKED); return (1); - } - if (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_ECHOED) { + } else { /* * treat like a case where the cookie expired i.e.: - dump * current cookie. - generate a new vtag. - resend init. @@ -739,15 +742,15 @@ sctp_handle_nat_colliding_state(struct sctp_tcb *stcb) SCTP_SET_STATE(stcb, SCTP_STATE_COOKIE_WAIT); sctp_stop_all_cookie_timers(stcb); sctp_toss_old_cookies(stcb, &stcb->asoc); - stcb->asoc.my_vtag = sctp_select_a_tag(stcb->sctp_ep, stcb->sctp_ep->sctp_lport, stcb->rport, 1); + stcb->asoc.my_vtag = new_vtag; head = &SCTP_BASE_INFO(sctp_asochash)[SCTP_PCBHASH_ASOC(stcb->asoc.my_vtag, SCTP_BASE_INFO(hashasocmark))]; /* * put it in the bucket in the vtag hash of assoc's for the * system */ LIST_INSERT_HEAD(head, stcb, sctp_asocs); - sctp_send_initiate(stcb->sctp_ep, stcb, SCTP_SO_NOT_LOCKED); SCTP_INP_INFO_WUNLOCK(); + sctp_send_initiate(stcb->sctp_ep, stcb, SCTP_SO_NOT_LOCKED); return (1); } return (0);