From owner-svn-src-head@freebsd.org Tue May 14 20:32:30 2019 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 1E7F51597EB1; Tue, 14 May 2019 20:32:30 +0000 (UTC) (envelope-from kevans@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 B6D0A837D0; Tue, 14 May 2019 20:32:29 +0000 (UTC) (envelope-from kevans@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 90A6A26184; Tue, 14 May 2019 20:32:29 +0000 (UTC) (envelope-from kevans@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x4EKWTYt074474; Tue, 14 May 2019 20:32:29 GMT (envelope-from kevans@FreeBSD.org) Received: (from kevans@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x4EKWTpt074473; Tue, 14 May 2019 20:32:29 GMT (envelope-from kevans@FreeBSD.org) Message-Id: <201905142032.x4EKWTpt074473@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: kevans set sender to kevans@FreeBSD.org using -f From: Kyle Evans Date: Tue, 14 May 2019 20:32:29 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r347578 - head/sys/net X-SVN-Group: head X-SVN-Commit-Author: kevans X-SVN-Commit-Paths: head/sys/net X-SVN-Commit-Revision: 347578 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: B6D0A837D0 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.98 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_SHORT(-0.98)[-0.979,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 May 2019 20:32:30 -0000 Author: kevans Date: Tue May 14 20:32:29 2019 New Revision: 347578 URL: https://svnweb.freebsd.org/changeset/base/347578 Log: tuntap: Defer clearing if_softc until after if_detach r346670 added an sx to close a race between the ifioctl handler and interface destruction. Unfortunately, it clears if_softc immediately after the interface is closed, but before if_detach has been invoked. Any time before detachment, an interface that's part of a bridge may still receive traffic that's pushed through tunstart/tunstart_l2 and promptly lead to a panic because if_softc is now NULL. Fix it by deferring the clearing of if_softc until after the interface has detached and thus been removed from the bridge. if_softc still gets cleared in case another thread has already entered the ioctl handler before it's replaced with ifdead_ioctl. Reported by: markj MFC after: 3 days Modified: head/sys/net/if_tuntap.c Modified: head/sys/net/if_tuntap.c ============================================================================== --- head/sys/net/if_tuntap.c Tue May 14 20:31:06 2019 (r347577) +++ head/sys/net/if_tuntap.c Tue May 14 20:32:29 2019 (r347578) @@ -537,9 +537,6 @@ tun_destroy(struct tuntap_softc *tp) TUN_UNLOCK(tp); CURVNET_SET(TUN2IFP(tp)->if_vnet); - sx_xlock(&tun_ioctl_sx); - TUN2IFP(tp)->if_softc = NULL; - sx_xunlock(&tun_ioctl_sx); destroy_dev(tp->tun_dev); seldrain(&tp->tun_rsel); @@ -551,6 +548,9 @@ tun_destroy(struct tuntap_softc *tp) bpfdetach(TUN2IFP(tp)); if_detach(TUN2IFP(tp)); } + sx_xlock(&tun_ioctl_sx); + TUN2IFP(tp)->if_softc = NULL; + sx_xunlock(&tun_ioctl_sx); free_unr(tp->tun_drv->unrhdr, TUN2IFP(tp)->if_dunit); if_free(TUN2IFP(tp)); mtx_destroy(&tp->tun_mtx);