Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754424Ab2JNPMj (ORCPT ); Sun, 14 Oct 2012 11:12:39 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:46193 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754350Ab2JNOmJ (ORCPT ); Sun, 14 Oct 2012 10:42:09 -0400 Message-Id: <20121014143552.710009990@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Sun, 14 Oct 2012 15:37:53 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Lin Ming , Julian Anastasov , Simon Horman , Pablo Neira Ayuso Subject: [ 140/147] ipvs: fix oops on NAT reply in br_nf context In-Reply-To: <20121014143533.742627615@decadent.org.uk> X-SA-Exim-Connect-IP: 77.75.106.1 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5379 Lines: 117 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lin Ming commit 9e33ce453f8ac8452649802bee1f410319408f4b upstream. IPVS should not reset skb->nf_bridge in FORWARD hook by calling nf_reset for NAT replies. It triggers oops in br_nf_forward_finish. [ 579.781508] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 [ 579.781669] IP: [] br_nf_forward_finish+0x58/0x112 [ 579.781792] PGD 218f9067 PUD 0 [ 579.781865] Oops: 0000 [#1] SMP [ 579.781945] CPU 0 [ 579.781983] Modules linked in: [ 579.782047] [ 579.782080] [ 579.782114] Pid: 4644, comm: qemu Tainted: G W 3.5.0-rc5-00006-g95e69f9 #282 Hewlett-Packard /30E8 [ 579.782300] RIP: 0010:[] [] br_nf_forward_finish+0x58/0x112 [ 579.782455] RSP: 0018:ffff88007b003a98 EFLAGS: 00010287 [ 579.782541] RAX: 0000000000000008 RBX: ffff8800762ead00 RCX: 000000000001670a [ 579.782653] RDX: 0000000000000000 RSI: 000000000000000a RDI: ffff8800762ead00 [ 579.782845] RBP: ffff88007b003ac8 R08: 0000000000016630 R09: ffff88007b003a90 [ 579.782957] R10: ffff88007b0038e8 R11: ffff88002da37540 R12: ffff88002da01a02 [ 579.783066] R13: ffff88002da01a80 R14: ffff88002d83c000 R15: ffff88002d82a000 [ 579.783177] FS: 0000000000000000(0000) GS:ffff88007b000000(0063) knlGS:00000000f62d1b70 [ 579.783306] CS: 0010 DS: 002b ES: 002b CR0: 000000008005003b [ 579.783395] CR2: 0000000000000004 CR3: 00000000218fe000 CR4: 00000000000027f0 [ 579.783505] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 579.783684] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 579.783795] Process qemu (pid: 4644, threadinfo ffff880021b20000, task ffff880021aba760) [ 579.783919] Stack: [ 579.783959] ffff88007693cedc ffff8800762ead00 ffff88002da01a02 ffff8800762ead00 [ 579.784110] ffff88002da01a02 ffff88002da01a80 ffff88007b003b18 ffffffff817b26c7 [ 579.784260] ffff880080000000 ffffffff81ef59f0 ffff8800762ead00 ffffffff81ef58b0 [ 579.784477] Call Trace: [ 579.784523] [ 579.784562] [ 579.784603] [] br_nf_forward_ip+0x275/0x2c8 [ 579.784707] [] nf_iterate+0x47/0x7d [ 579.784797] [] ? br_dev_queue_push_xmit+0xae/0xae [ 579.784906] [] nf_hook_slow+0x6d/0x102 [ 579.784995] [] ? br_dev_queue_push_xmit+0xae/0xae [ 579.785175] [] ? _raw_write_unlock_bh+0x19/0x1b [ 579.785179] [] __br_forward+0x97/0xa2 [ 579.785179] [] br_handle_frame_finish+0x1a6/0x257 [ 579.785179] [] br_nf_pre_routing_finish+0x26d/0x2cb [ 579.785179] [] br_nf_pre_routing+0x55d/0x5c1 [ 579.785179] [] nf_iterate+0x47/0x7d [ 579.785179] [] ? br_handle_local_finish+0x44/0x44 [ 579.785179] [] nf_hook_slow+0x6d/0x102 [ 579.785179] [] ? br_handle_local_finish+0x44/0x44 [ 579.785179] [] ? sky2_poll+0xb35/0xb54 [ 579.785179] [] br_handle_frame+0x213/0x229 [ 579.785179] [] ? br_handle_frame_finish+0x257/0x257 [ 579.785179] [] __netif_receive_skb+0x2b4/0x3f1 [ 579.785179] [] process_backlog+0x99/0x1e2 [ 579.785179] [] net_rx_action+0xdf/0x242 [ 579.785179] [] __do_softirq+0xc1/0x1e0 [ 579.785179] [] ? trace_hardirqs_off_thunk+0x3a/0x6c [ 579.785179] [] call_softirq+0x1c/0x30 The steps to reproduce as follow, 1. On Host1, setup brige br0(192.168.1.106) 2. Boot a kvm guest(192.168.1.105) on Host1 and start httpd 3. Start IPVS service on Host1 ipvsadm -A -t 192.168.1.106:80 -s rr ipvsadm -a -t 192.168.1.106:80 -r 192.168.1.105:80 -m 4. Run apache benchmark on Host2(192.168.1.101) ab -n 1000 http://192.168.1.106/ ip_vs_reply4 ip_vs_out handle_response ip_vs_notrack nf_reset() { skb->nf_bridge = NULL; } Actually, IPVS wants in this case just to replace nfct with untracked version. So replace the nf_reset(skb) call in ip_vs_notrack() with a nf_conntrack_put(skb->nfct) call. Signed-off-by: Lin Ming Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman Signed-off-by: Pablo Neira Ayuso Signed-off-by: Ben Hutchings --- include/net/ip_vs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h index d6146b4..95374d1 100644 --- a/include/net/ip_vs.h +++ b/include/net/ip_vs.h @@ -1425,7 +1425,7 @@ static inline void ip_vs_notrack(struct sk_buff *skb) struct nf_conn *ct = nf_ct_get(skb, &ctinfo); if (!ct || !nf_ct_is_untracked(ct)) { - nf_reset(skb); + nf_conntrack_put(skb->nfct); skb->nfct = &nf_ct_untracked_get()->ct_general; skb->nfctinfo = IP_CT_NEW; nf_conntrack_get(skb->nfct); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/