From patchwork Mon Mar 5 12:24:29 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans Schillstrom X-Patchwork-Id: 144670 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id E1B28B6EEA for ; Mon, 5 Mar 2012 23:24:37 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756915Ab2CEMYf (ORCPT ); Mon, 5 Mar 2012 07:24:35 -0500 Received: from mailgw9.se.ericsson.net ([193.180.251.57]:50337 "EHLO mailgw9.se.ericsson.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756561Ab2CEMYe (ORCPT ); Mon, 5 Mar 2012 07:24:34 -0500 X-AuditID: c1b4fb39-b7bf2ae0000069a1-a3-4f54b0801344 Received: from esessmw0197.eemea.ericsson.se (Unknown_Domain [153.88.253.124]) by mailgw9.se.ericsson.net (Symantec Mail Security) with SMTP id 52.BC.27041.080B45F4; Mon, 5 Mar 2012 13:24:32 +0100 (CET) Received: from seassled11.rnd.as.sw.ericsson.se (153.88.115.8) by esessmw0197.eemea.ericsson.se (153.88.115.88) with Microsoft SMTP Server id 8.3.213.0; Mon, 5 Mar 2012 13:24:31 +0100 Received: by seassled11.rnd.as.sw.ericsson.se (Postfix, from userid 88893) id 205344063A2; Mon, 5 Mar 2012 13:24:29 +0100 (CET) From: Hans Schillstrom To: , , , CC: , Hans Schillstrom Subject: [PATCH 1/1] conntrack, suspicious RCU usage Date: Mon, 5 Mar 2012 13:24:29 +0100 Message-ID: <1330950269-32668-1-git-send-email-hans.schillstrom@ericsson.com> X-Mailer: git-send-email 1.6.0.2 MIME-Version: 1.0 X-Brightmail-Tracker: AAAAAA== Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org From: Hans Schillstrom Hello Pablo I think you lost this patch from Eric, I updated the patch for the latest nf_conntrack_netlink.c Well, __nf_ct_l4proto_find() being out of line and the way we already use rcu_read_lock() in this code, it seems following patch is the most natural way to cope with these lockdep warnings. Thanks [PATCH] netfilter: ctnetlink: fix lockep splats net/netfilter/nf_conntrack_proto.c:70 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 3 locks held by conntrack/3235: nfnl_lock+0x17/0x20 netlink_dump+0x32/0x240 ctnetlink_dump_table+0x3e/0x170 [nf_conntrack_netlink] stack backtrace: Pid: 3235, comm: conntrack Tainted: G W 3.2.0+ #511 Call Trace: [] lockdep_rcu_suspicious+0xe5/0x100 [] __nf_ct_l4proto_find+0x81/0xb0 [nf_conntrack] [] ctnetlink_fill_info+0x215/0x5f0 [nf_conntrack_netlink] [] ctnetlink_dump_table+0xd1/0x170 [nf_conntrack_netlink] [] netlink_dump+0x7f/0x240 [] ? trace_hardirqs_on+0xd/0x10 [] netlink_dump_start+0xdf/0x190 [] ? ctnetlink_change_nat_seq_adj+0x160/0x160 [nf_conntrack_netlink] [] ? ctnetlink_get_conntrack+0x2a0/0x2a0 [nf_conntrack_netlink] [] ctnetlink_get_conntrack+0x89/0x2a0 [nf_conntrack_netlink] [] nfnetlink_rcv_msg+0x467/0x5f0 [] ? nfnetlink_rcv_msg+0x49c/0x5f0 [] ? nfnetlink_rcv_msg+0x342/0x5f0 [] ? get_parent_ip+0x11/0x50 [] ? nfnetlink_subsys_register+0x60/0x60 [] netlink_rcv_skb+0xa9/0xd0 [] nfnetlink_rcv+0x15/0x20 [] netlink_unicast+0x1ae/0x1f0 [] netlink_sendmsg+0x2c6/0x320 [] sock_sendmsg+0x117/0x130 [] ? might_fault+0x53/0xb0 [] ? might_fault+0x9c/0xb0 [] ? might_fault+0x53/0xb0 [] ? move_addr_to_kernel+0x71/0x80 [] sys_sendto+0xfe/0x130 [] ? sys_bind+0xb4/0xd0 [] ? retint_swapgs+0xe/0x13 [] system_call_fastpath+0x16/0x1b Reported-by: Hans Schillstrom Signed-off-by: Eric Dumazet Signed-off-by: Hans Schillstrom --- net/netfilter/nf_conntrack_netlink.c | 40 ++++++++++++++++++++------------- 1 files changed, 24 insertions(+), 16 deletions(-) diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 04fb409..f3d7556 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -110,15 +110,16 @@ ctnetlink_dump_tuples(struct sk_buff *skb, struct nf_conntrack_l3proto *l3proto; struct nf_conntrack_l4proto *l4proto; + rcu_read_lock(); l3proto = __nf_ct_l3proto_find(tuple->src.l3num); ret = ctnetlink_dump_tuples_ip(skb, tuple, l3proto); - if (unlikely(ret < 0)) - return ret; - - l4proto = __nf_ct_l4proto_find(tuple->src.l3num, tuple->dst.protonum); - ret = ctnetlink_dump_tuples_proto(skb, tuple, l4proto); - + if (ret >= 0) { + l4proto = __nf_ct_l4proto_find(tuple->src.l3num, + tuple->dst.protonum); + ret = ctnetlink_dump_tuples_proto(skb, tuple, l4proto); + } + rcu_read_unlock(); return ret; } @@ -712,9 +713,11 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb) struct hlist_nulls_node *n; struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh); u_int8_t l3proto = nfmsg->nfgen_family; + int res; #ifdef CONFIG_NF_CONNTRACK_MARK const struct ctnetlink_dump_filter *filter = cb->data; #endif + spin_lock_bh(&nf_conntrack_lock); last = (struct nf_conn *)cb->args[1]; for (; cb->args[0] < net->ct.htable_size; cb->args[0]++) { @@ -740,11 +743,14 @@ restart: continue; } #endif - if (ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).pid, - cb->nlh->nlmsg_seq, - NFNL_MSG_TYPE( - cb->nlh->nlmsg_type), - ct) < 0) { + rcu_read_lock(); + res = + ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).pid, + cb->nlh->nlmsg_seq, + NFNL_MSG_TYPE(cb->nlh->nlmsg_type), + ct); + rcu_read_unlock(); + if (res < 0) { nf_conntrack_get(&ct->ct_general); cb->args[1] = (unsigned long)ct; goto out; @@ -1649,14 +1655,16 @@ ctnetlink_exp_dump_mask(struct sk_buff *skb, if (!nest_parms) goto nla_put_failure; + rcu_read_lock(); l3proto = __nf_ct_l3proto_find(tuple->src.l3num); ret = ctnetlink_dump_tuples_ip(skb, &m, l3proto); - - if (unlikely(ret < 0)) - goto nla_put_failure; - - l4proto = __nf_ct_l4proto_find(tuple->src.l3num, tuple->dst.protonum); + if (ret >= 0) { + l4proto = __nf_ct_l4proto_find(tuple->src.l3num, + tuple->dst.protonum); ret = ctnetlink_dump_tuples_proto(skb, &m, l4proto); + } + rcu_read_unlock(); + if (unlikely(ret < 0)) goto nla_put_failure;