From owner-svn-src-head@freebsd.org Sat Nov 12 19:03:25 2016 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 07AF6C3D2AA; Sat, 12 Nov 2016 19:03:25 +0000 (UTC) (envelope-from rstone@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 mx1.freebsd.org (Postfix) with ESMTPS id BD468F4A; Sat, 12 Nov 2016 19:03:24 +0000 (UTC) (envelope-from rstone@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id uACJ3NTA070197; Sat, 12 Nov 2016 19:03:23 GMT (envelope-from rstone@FreeBSD.org) Received: (from rstone@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id uACJ3NjC070196; Sat, 12 Nov 2016 19:03:23 GMT (envelope-from rstone@FreeBSD.org) Message-Id: <201611121903.uACJ3NjC070196@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: rstone set sender to rstone@FreeBSD.org using -f From: Ryan Stone Date: Sat, 12 Nov 2016 19:03:23 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r308580 - head/sys/net X-SVN-Group: head 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: 2.1.23 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: Sat, 12 Nov 2016 19:03:25 -0000 Author: rstone Date: Sat Nov 12 19:03:23 2016 New Revision: 308580 URL: https://svnweb.freebsd.org/changeset/base/308580 Log: Don't read if_counters with if_addr_lock held Calling into an ifnet implementation with the if_addr_lock already held can cause a LOR and potentially a deadlock, as ifnet implementations typically can take the if_addr_lock after their own locks during configuration. Refactor a sysctl handler that was violating this to read if_counter data in a temporary buffer before the if_addr_lock is taken, and then copying the data in its final location later, when the if_addr_lock is held. PR: 194109 Reported by: Jean-Sebastien Pedron MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D8498 Reviewed by: sbruno Modified: head/sys/net/rtsock.c Modified: head/sys/net/rtsock.c ============================================================================== --- head/sys/net/rtsock.c Sat Nov 12 18:57:38 2016 (r308579) +++ head/sys/net/rtsock.c Sat Nov 12 19:03:23 2016 (r308580) @@ -1566,8 +1566,8 @@ sysctl_dumpentry(struct radix_node *rn, } static int -sysctl_iflist_ifml(struct ifnet *ifp, struct rt_addrinfo *info, - struct walkarg *w, int len) +sysctl_iflist_ifml(struct ifnet *ifp, const struct if_data *src_ifd, + struct rt_addrinfo *info, struct walkarg *w, int len) { struct if_msghdrl *ifm; struct if_data *ifd; @@ -1598,14 +1598,14 @@ sysctl_iflist_ifml(struct ifnet *ifp, st ifd = &ifm->ifm_data; } - if_data_copy(ifp, ifd); + memcpy(ifd, src_ifd, sizeof(*ifd)); return (SYSCTL_OUT(w->w_req, (caddr_t)ifm, len)); } static int -sysctl_iflist_ifm(struct ifnet *ifp, struct rt_addrinfo *info, - struct walkarg *w, int len) +sysctl_iflist_ifm(struct ifnet *ifp, const struct if_data *src_ifd, + struct rt_addrinfo *info, struct walkarg *w, int len) { struct if_msghdr *ifm; struct if_data *ifd; @@ -1630,7 +1630,7 @@ sysctl_iflist_ifm(struct ifnet *ifp, str ifd = &ifm->ifm_data; } - if_data_copy(ifp, ifd); + memcpy(ifd, src_ifd, sizeof(*ifd)); return (SYSCTL_OUT(w->w_req, (caddr_t)ifm, len)); } @@ -1705,15 +1705,18 @@ sysctl_iflist(int af, struct walkarg *w) { struct ifnet *ifp; struct ifaddr *ifa; + struct if_data ifd; struct rt_addrinfo info; int len, error = 0; struct sockaddr_storage ss; bzero((caddr_t)&info, sizeof(info)); + bzero(&ifd, sizeof(ifd)); IFNET_RLOCK_NOSLEEP(); TAILQ_FOREACH(ifp, &V_ifnet, if_link) { if (w->w_arg && w->w_arg != ifp->if_index) continue; + if_data_copy(ifp, &ifd); IF_ADDR_RLOCK(ifp); ifa = ifp->if_addr; info.rti_info[RTAX_IFP] = ifa->ifa_addr; @@ -1723,9 +1726,11 @@ sysctl_iflist(int af, struct walkarg *w) info.rti_info[RTAX_IFP] = NULL; if (w->w_req && w->w_tmem) { if (w->w_op == NET_RT_IFLISTL) - error = sysctl_iflist_ifml(ifp, &info, w, len); + error = sysctl_iflist_ifml(ifp, &ifd, &info, w, + len); else - error = sysctl_iflist_ifm(ifp, &info, w, len); + error = sysctl_iflist_ifm(ifp, &ifd, &info, w, + len); if (error) goto done; }