From owner-svn-src-stable@freebsd.org Wed May 22 22:34:36 2019 Return-Path: Delivered-To: svn-src-stable@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 5B661158F877; Wed, 22 May 2019 22:34:36 +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 ECFD56E25E; Wed, 22 May 2019 22:34:35 +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 ACAA623ECD; Wed, 22 May 2019 22:34:35 +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 x4MMYZ8u035655; Wed, 22 May 2019 22:34:35 GMT (envelope-from kevans@FreeBSD.org) Received: (from kevans@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x4MMYZho035654; Wed, 22 May 2019 22:34:35 GMT (envelope-from kevans@FreeBSD.org) Message-Id: <201905222234.x4MMYZho035654@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: kevans set sender to kevans@FreeBSD.org using -f From: Kyle Evans Date: Wed, 22 May 2019 22:34:35 +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: r348124 - stable/12/sys/net X-SVN-Group: stable-12 X-SVN-Commit-Author: kevans X-SVN-Commit-Paths: stable/12/sys/net X-SVN-Commit-Revision: 348124 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: ECFD56E25E 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_LONG(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-0.98)[-0.979,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US] 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: Wed, 22 May 2019 22:34:36 -0000 Author: kevans Date: Wed May 22 22:34:35 2019 New Revision: 348124 URL: https://svnweb.freebsd.org/changeset/base/348124 Log: MFC r347578: tun/tap: Defer clearing if_softc until after if_detach (Commit massaged to match stable structure; tun and tap have been merged in head) 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. Modified: stable/12/sys/net/if_tap.c stable/12/sys/net/if_tun.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/net/if_tap.c ============================================================================== --- stable/12/sys/net/if_tap.c Wed May 22 21:47:26 2019 (r348123) +++ stable/12/sys/net/if_tap.c Wed May 22 22:34:35 2019 (r348124) @@ -223,15 +223,17 @@ tap_destroy(struct tap_softc *tp) struct ifnet *ifp = tp->tap_ifp; CURVNET_SET(ifp->if_vnet); - sx_xlock(&tap_ioctl_sx); - ifp->if_softc = NULL; - sx_xunlock(&tap_ioctl_sx); destroy_dev(tp->tap_dev); seldrain(&tp->tap_rsel); knlist_clear(&tp->tap_rsel.si_note, 0); knlist_destroy(&tp->tap_rsel.si_note); ether_ifdetach(ifp); + + sx_xlock(&tap_ioctl_sx); + ifp->if_softc = NULL; + sx_xunlock(&tap_ioctl_sx); + if_free(ifp); mtx_destroy(&tp->tap_mtx); Modified: stable/12/sys/net/if_tun.c ============================================================================== --- stable/12/sys/net/if_tun.c Wed May 22 21:47:26 2019 (r348123) +++ stable/12/sys/net/if_tun.c Wed May 22 22:34:35 2019 (r348124) @@ -278,13 +278,15 @@ tun_destroy(struct tun_softc *tp) mtx_unlock(&tp->tun_mtx); CURVNET_SET(TUN2IFP(tp)->if_vnet); - sx_xlock(&tun_ioctl_sx); - TUN2IFP(tp)->if_softc = NULL; - sx_xunlock(&tun_ioctl_sx); dev = tp->tun_dev; bpfdetach(TUN2IFP(tp)); if_detach(TUN2IFP(tp)); + + sx_xlock(&tun_ioctl_sx); + TUN2IFP(tp)->if_softc = NULL; + sx_xunlock(&tun_ioctl_sx); + free_unr(tun_unrhdr, TUN2IFP(tp)->if_dunit); if_free(TUN2IFP(tp)); destroy_dev(dev);