[ovs-dev] [PATCHv2 7/9] datapath: Orphan skbs before IPv6 defrag
Joe Stringer
joe at ovn.org
Mon May 2 18:19:16 UTC 2016
Upstream commit:
openvswitch: Orphan skbs before IPv6 defrag
This is the IPv6 counterpart to commit 8282f27449bf ("inet: frag: Always
orphan skbs inside ip_defrag()").
Prior to commit 029f7f3b8701 ("netfilter: ipv6: nf_defrag: avoid/free
clone operations"), ipv6 fragments sent to nf_ct_frag6_gather() would be
cloned (implicitly orphaning) prior to queueing for reassembly. As such,
when the IPv6 message is eventually reassembled, the skb->sk for all
fragments would be NULL. After that commit was introduced, rather than
cloning, the original skbs were queued directly without orphaning. The
end result is that all frags except for the first and last may have a
socket attached.
This commit explicitly orphans such skbs during nf_ct_frag6_gather() to
prevent BUG_ON(skb->sk) during a later call to ip6_fragment().
kernel BUG at net/ipv6/ip6_output.c:631!
[...]
Call Trace:
<IRQ>
[<ffffffff810be8f7>] ? __lock_acquire+0x927/0x20a0
[<ffffffffa042c7c0>] ? do_output.isra.28+0x1b0/0x1b0 [openvswitch]
[<ffffffff810bb8a2>] ? __lock_is_held+0x52/0x70
[<ffffffffa042c587>] ovs_fragment+0x1f7/0x280 [openvswitch]
[<ffffffff810bdab5>] ? mark_held_locks+0x75/0xa0
[<ffffffff817be416>] ? _raw_spin_unlock_irqrestore+0x36/0x50
[<ffffffff81697ea0>] ? dst_discard_out+0x20/0x20
[<ffffffff81697e80>] ? dst_ifdown+0x80/0x80
[<ffffffffa042c703>] do_output.isra.28+0xf3/0x1b0 [openvswitch]
[<ffffffffa042d279>] do_execute_actions+0x709/0x12c0 [openvswitch]
[<ffffffffa04340a4>] ? ovs_flow_stats_update+0x74/0x1e0 [openvswitch]
[<ffffffffa04340d1>] ? ovs_flow_stats_update+0xa1/0x1e0 [openvswitch]
[<ffffffff817be387>] ? _raw_spin_unlock+0x27/0x40
[<ffffffffa042de75>] ovs_execute_actions+0x45/0x120 [openvswitch]
[<ffffffffa0432d65>] ovs_dp_process_packet+0x85/0x150 [openvswitch]
[<ffffffff817be387>] ? _raw_spin_unlock+0x27/0x40
[<ffffffffa042def4>] ovs_execute_actions+0xc4/0x120 [openvswitch]
[<ffffffffa0432d65>] ovs_dp_process_packet+0x85/0x150 [openvswitch]
[<ffffffffa04337f2>] ? key_extract+0x442/0xc10 [openvswitch]
[<ffffffffa043b26d>] ovs_vport_receive+0x5d/0xb0 [openvswitch]
[<ffffffff810be8f7>] ? __lock_acquire+0x927/0x20a0
[<ffffffff810be8f7>] ? __lock_acquire+0x927/0x20a0
[<ffffffff810be8f7>] ? __lock_acquire+0x927/0x20a0
[<ffffffff817be416>] ? _raw_spin_unlock_irqrestore+0x36/0x50
[<ffffffffa043c11d>] internal_dev_xmit+0x6d/0x150 [openvswitch]
[<ffffffffa043c0b5>] ? internal_dev_xmit+0x5/0x150 [openvswitch]
[<ffffffff8168fb5f>] dev_hard_start_xmit+0x2df/0x660
[<ffffffff8168f5ea>] ? validate_xmit_skb.isra.105.part.106+0x1a/0x2b0
[<ffffffff81690925>] __dev_queue_xmit+0x8f5/0x950
[<ffffffff81690080>] ? __dev_queue_xmit+0x50/0x950
[<ffffffff810bdab5>] ? mark_held_locks+0x75/0xa0
[<ffffffff81690990>] dev_queue_xmit+0x10/0x20
[<ffffffff8169a418>] neigh_resolve_output+0x178/0x220
[<ffffffff81752759>] ? ip6_finish_output2+0x219/0x7b0
[<ffffffff81752759>] ip6_finish_output2+0x219/0x7b0
[<ffffffff817525a5>] ? ip6_finish_output2+0x65/0x7b0
[<ffffffff816cde2b>] ? ip_idents_reserve+0x6b/0x80
[<ffffffff8175488f>] ? ip6_fragment+0x93f/0xc50
[<ffffffff81754af1>] ip6_fragment+0xba1/0xc50
[<ffffffff81752540>] ? ip6_flush_pending_frames+0x40/0x40
[<ffffffff81754c6b>] ip6_finish_output+0xcb/0x1d0
[<ffffffff81754dcf>] ip6_output+0x5f/0x1a0
[<ffffffff81754ba0>] ? ip6_fragment+0xc50/0xc50
[<ffffffff81797fbd>] ip6_local_out+0x3d/0x80
[<ffffffff817554df>] ip6_send_skb+0x2f/0xc0
[<ffffffff817555bd>] ip6_push_pending_frames+0x4d/0x50
[<ffffffff817796cc>] icmpv6_push_pending_frames+0xac/0xe0
[<ffffffff8177a4be>] icmpv6_echo_reply+0x42e/0x500
[<ffffffff8177acbf>] icmpv6_rcv+0x4cf/0x580
[<ffffffff81755ac7>] ip6_input_finish+0x1a7/0x690
[<ffffffff81755925>] ? ip6_input_finish+0x5/0x690
[<ffffffff817567a0>] ip6_input+0x30/0xa0
[<ffffffff81755920>] ? ip6_rcv_finish+0x1a0/0x1a0
[<ffffffff817557ce>] ip6_rcv_finish+0x4e/0x1a0
[<ffffffff8175640f>] ipv6_rcv+0x45f/0x7c0
[<ffffffff81755fe6>] ? ipv6_rcv+0x36/0x7c0
[<ffffffff81755780>] ? ip6_make_skb+0x1c0/0x1c0
[<ffffffff8168b649>] __netif_receive_skb_core+0x229/0xb80
[<ffffffff810bdab5>] ? mark_held_locks+0x75/0xa0
[<ffffffff8168c07f>] ? process_backlog+0x6f/0x230
[<ffffffff8168bfb6>] __netif_receive_skb+0x16/0x70
[<ffffffff8168c088>] process_backlog+0x78/0x230
[<ffffffff8168c0ed>] ? process_backlog+0xdd/0x230
[<ffffffff8168db43>] net_rx_action+0x203/0x480
[<ffffffff810bdab5>] ? mark_held_locks+0x75/0xa0
[<ffffffff817c156e>] __do_softirq+0xde/0x49f
[<ffffffff81752768>] ? ip6_finish_output2+0x228/0x7b0
[<ffffffff817c070c>] do_softirq_own_stack+0x1c/0x30
<EOI>
[<ffffffff8106f88b>] do_softirq.part.18+0x3b/0x40
[<ffffffff8106f946>] __local_bh_enable_ip+0xb6/0xc0
[<ffffffff81752791>] ip6_finish_output2+0x251/0x7b0
[<ffffffff81754af1>] ? ip6_fragment+0xba1/0xc50
[<ffffffff816cde2b>] ? ip_idents_reserve+0x6b/0x80
[<ffffffff8175488f>] ? ip6_fragment+0x93f/0xc50
[<ffffffff81754af1>] ip6_fragment+0xba1/0xc50
[<ffffffff81752540>] ? ip6_flush_pending_frames+0x40/0x40
[<ffffffff81754c6b>] ip6_finish_output+0xcb/0x1d0
[<ffffffff81754dcf>] ip6_output+0x5f/0x1a0
[<ffffffff81754ba0>] ? ip6_fragment+0xc50/0xc50
[<ffffffff81797fbd>] ip6_local_out+0x3d/0x80
[<ffffffff817554df>] ip6_send_skb+0x2f/0xc0
[<ffffffff817555bd>] ip6_push_pending_frames+0x4d/0x50
[<ffffffff81778558>] rawv6_sendmsg+0xa28/0xe30
[<ffffffff81719097>] ? inet_sendmsg+0xc7/0x1d0
[<ffffffff817190d6>] inet_sendmsg+0x106/0x1d0
[<ffffffff81718fd5>] ? inet_sendmsg+0x5/0x1d0
[<ffffffff8166d078>] sock_sendmsg+0x38/0x50
[<ffffffff8166d4d6>] SYSC_sendto+0xf6/0x170
[<ffffffff8100201b>] ? trace_hardirqs_on_thunk+0x1b/0x1d
[<ffffffff8166e38e>] SyS_sendto+0xe/0x10
[<ffffffff817bebe5>] entry_SYSCALL_64_fastpath+0x18/0xa8
Code: 06 48 83 3f 00 75 26 48 8b 87 d8 00 00 00 2b 87 d0 00 00 00 48 39 d0 72 14 8b 87 e4 00 00 00 83 f8 01 75 09 48 83 7f 18 00 74 9a <0f> 0b 41 8b 86 cc 00 00 00 49 8#
RIP [<ffffffff8175468a>] ip6_fragment+0x73a/0xc50
RSP <ffff880072803120>
Fixes: 029f7f3b8701 ("netfilter: ipv6: nf_defrag: avoid/free clone
operations")
Reported-by: Daniele Di Proietto <diproiettod at vmware.com>
Signed-off-by: Joe Stringer <joe at ovn.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Upstream: 49e261a8a21e ("openvswitch: Orphan skbs before IPv6 defrag")
Signed-off-by: Joe Stringer <joe at ovn.org>
---
v2: Update upstream commit IDs
v1: Initial Post.
---
datapath/conntrack.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/datapath/conntrack.c b/datapath/conntrack.c
index 813094c7ecf6..49c299b5bd55 100644
--- a/datapath/conntrack.c
+++ b/datapath/conntrack.c
@@ -331,6 +331,7 @@ static int handle_fragments(struct net *net, struct sw_flow_key *key,
} else if (key->eth.type == htons(ETH_P_IPV6)) {
enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
+ skb_orphan(skb);
memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
err = nf_ct_frag6_gather(net, skb, user);
if (err)
--
2.1.4
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