From owner-freebsd-net@freebsd.org Fri Jan 25 08:11:53 2019 Return-Path: Delivered-To: freebsd-net@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 E14C514AC3B7 for ; Fri, 25 Jan 2019 08:11:52 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id 640D96EE66 for ; Fri, 25 Jan 2019 08:11:52 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.ysv.freebsd.org (Postfix) id 223F714AC3B6; Fri, 25 Jan 2019 08:11:52 +0000 (UTC) Delivered-To: net@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 F133F14AC3B4 for ; Fri, 25 Jan 2019 08:11:51 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.ysv.freebsd.org (mxrelay.ysv.freebsd.org [IPv6:2001:1900:2254:206a::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.ysv.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 8CD7C6EE5F for ; Fri, 25 Jan 2019 08:11:51 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.ysv.freebsd.org (Postfix) with ESMTPS id D4B6B1A3C4 for ; Fri, 25 Jan 2019 08:11:50 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id x0P8BowA063394 for ; Fri, 25 Jan 2019 08:11:50 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id x0P8BorT063393 for net@FreeBSD.org; Fri, 25 Jan 2019 08:11:50 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: net@FreeBSD.org Subject: [Bug 235097] ci runs panic with use-after-free when running sys/netpfil/pf/nat tests Date: Fri, 25 Jan 2019 08:11:51 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: ae@FreeBSD.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: net@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 25 Jan 2019 08:11:53 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D235097 --- Comment #14 from Andrey V. Elsukov --- (In reply to Kristof Provost from comment #12) > The following appears to fix the panic in comment #6: >=20 > diff --git a/sys/net/if.c b/sys/net/if.c > index a6552f80f37..7e3e662d342 100644 > --- a/sys/net/if.c > +++ b/sys/net/if.c > @@ -1194,6 +1195,11 @@ if_detach_internal(struct ifnet *ifp, int vmove, > struct if_clone **ifcp) > if (!CK_STAILQ_EMPTY(&ifp->if_addrhead)) { > ifa =3D CK_STAILQ_FIRST(&ifp->if_addrhead); > CK_STAILQ_REMOVE(&ifp->if_addrhead, ifa, ifaddr, > ifa_link); > + //KASSERT(ifa !=3D ifp->if_addr, ("")); > + if (ifa =3D=3D ifp->if_addr) { > + ifp->if_addr =3D NULL; > + printf("KP: set ifp->if_addr to NULL\n"); > + } > IF_ADDR_WUNLOCK(ifp); > ifa_free(ifa); > } else >=20 > We free the ifaddr, but we can still have a pointer to it in ifp->if_addr. > This check triggers, and in several test runs with this patch I've not > managed to reproduce the panic any more. I'm doing more runs, because this > problem comes and goes, but I hope this will be a useful pointer to someo= ne > who knows that code better than me. ifa_free() does not free the memory immediately, so it is safe to make acce= ss to ifp->if_addr while you are in NET_EPOCH() section. --=20 You are receiving this mail because: You are the assignee for the bug.=