From owner-svn-src-head@freebsd.org Tue Sep 8 14:54:11 2020 Return-Path: Delivered-To: svn-src-head@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 7405A3CC162; Tue, 8 Sep 2020 14:54:11 +0000 (UTC) (envelope-from kp@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 4Bm7TH2Vfnz3bws; Tue, 8 Sep 2020 14:54:11 +0000 (UTC) (envelope-from kp@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 3A86D12337; Tue, 8 Sep 2020 14:54:11 +0000 (UTC) (envelope-from kp@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 088EsB8k044473; Tue, 8 Sep 2020 14:54:11 GMT (envelope-from kp@FreeBSD.org) Received: (from kp@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 088EsAkf044471; Tue, 8 Sep 2020 14:54:10 GMT (envelope-from kp@FreeBSD.org) Message-Id: <202009081454.088EsAkf044471@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: kp set sender to kp@FreeBSD.org using -f From: Kristof Provost Date: Tue, 8 Sep 2020 14:54:10 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r365457 - head/sys/net X-SVN-Group: head X-SVN-Commit-Author: kp X-SVN-Commit-Paths: head/sys/net X-SVN-Commit-Revision: 365457 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.33 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, 08 Sep 2020 14:54:11 -0000 Author: kp Date: Tue Sep 8 14:54:10 2020 New Revision: 365457 URL: https://svnweb.freebsd.org/changeset/base/365457 Log: net: mitigate vnet / epair cleanup races There's a race where dying vnets move their interfaces back to their original vnet, and if_epair cleanup (where deleting one interface also deletes the other end of the epair). This is commonly triggered by the pf tests, but also by cleanup of vnet jails. As we've not yet been able to fix the root cause of the issue work around the panic by not dereferencing a NULL softc in epair_qflush() and by not re-attaching DYING interfaces. This isn't a full fix, but makes a very common panic far less likely. PR: 244703, 238870 Reviewed by: lutz_donnerhacke.de MFC after: 4 days Differential Revision: https://reviews.freebsd.org/D26324 Modified: head/sys/net/if.c head/sys/net/if_epair.c Modified: head/sys/net/if.c ============================================================================== --- head/sys/net/if.c Tue Sep 8 13:24:44 2020 (r365456) +++ head/sys/net/if.c Tue Sep 8 14:54:10 2020 (r365457) @@ -1298,6 +1298,11 @@ if_vmove(struct ifnet *ifp, struct vnet *new_vnet) ifindex_free_locked(ifp->if_index); IFNET_WUNLOCK(); + + /* Don't re-attach DYING interfaces. */ + if (ifp->if_flags & IFF_DYING) + return (0); + /* * Perform interface-specific reassignment tasks, if provided by * the driver. Modified: head/sys/net/if_epair.c ============================================================================== --- head/sys/net/if_epair.c Tue Sep 8 13:24:44 2020 (r365456) +++ head/sys/net/if_epair.c Tue Sep 8 14:54:10 2020 (r365457) @@ -611,8 +611,14 @@ epair_qflush(struct ifnet *ifp) struct epair_softc *sc; sc = ifp->if_softc; - KASSERT(sc != NULL, ("%s: ifp=%p, epair_softc gone? sc=%p\n", - __func__, ifp, sc)); + + /* + * See epair_clone_destroy(), we can end up getting called twice. + * Don't do anything on the second call. + */ + if (sc == NULL) + return; + /* * Remove this ifp from all backpointer lists. The interface will not * usable for flushing anyway nor should it have anything to flush