From owner-svn-src-all@freebsd.org Fri Sep 25 18:55:50 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 D1AC23E0B0B; Fri, 25 Sep 2020 18:55:50 +0000 (UTC) (envelope-from markj@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 "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Byh2G59qTz4PHP; Fri, 25 Sep 2020 18:55:50 +0000 (UTC) (envelope-from markj@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 9433017B98; Fri, 25 Sep 2020 18:55:50 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 08PItovD022313; Fri, 25 Sep 2020 18:55:50 GMT (envelope-from markj@FreeBSD.org) Received: (from markj@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 08PItop2022312; Fri, 25 Sep 2020 18:55:50 GMT (envelope-from markj@FreeBSD.org) Message-Id: <202009251855.08PItop2022312@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: markj set sender to markj@FreeBSD.org using -f From: Mark Johnston Date: Fri, 25 Sep 2020 18:55:50 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r366167 - head/sys/netgraph X-SVN-Group: head X-SVN-Commit-Author: markj X-SVN-Commit-Paths: head/sys/netgraph X-SVN-Commit-Revision: 366167 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: 2.1.33 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: Fri, 25 Sep 2020 18:55:50 -0000 Author: markj Date: Fri Sep 25 18:55:50 2020 New Revision: 366167 URL: https://svnweb.freebsd.org/changeset/base/366167 Log: ng_l2tp: Fix callout synchronization in the rexmit timeout handler A received control packet may cause the transmit queue to be flushed, in which case ng_l2tp_seq_recv_nr() cancels the transmit timeout handler. The handler checks to see if it was cancelled before doing anything, but did so before acquiring the node lock, so a small race window could cause ng_l2tp_seq_rack_timeout() to attempt to flush an empty queue, ultimately causing a null pointer dereference. PR: 241133 Reviewed by: bz, glebius, Lutz Donnerhacke MFC after: 3 days Sponsored by: Rubicon Communications, LLC (Netgate) Differential Revision: https://reviews.freebsd.org/D26548 Modified: head/sys/netgraph/ng_l2tp.c Modified: head/sys/netgraph/ng_l2tp.c ============================================================================== --- head/sys/netgraph/ng_l2tp.c Fri Sep 25 18:21:50 2020 (r366166) +++ head/sys/netgraph/ng_l2tp.c Fri Sep 25 18:55:50 2020 (r366167) @@ -1453,15 +1453,17 @@ ng_l2tp_seq_rack_timeout(node_p node, hook_p hook, voi struct mbuf *m; u_int delay; - /* Make sure callout is still active before doing anything */ - if (callout_pending(&seq->rack_timer) || - (!callout_active(&seq->rack_timer))) - return; - /* Sanity check */ L2TP_SEQ_CHECK(seq); mtx_lock(&seq->mtx); + /* Make sure callout is still active before doing anything */ + if (callout_pending(&seq->rack_timer) || + !callout_active(&seq->rack_timer)) { + mtx_unlock(&seq->mtx); + return; + } + priv->stats.xmitRetransmits++; /* Have we reached the retransmit limit? If so, notify owner. */