This is the IPv6 equivalent of 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@xxxxxxxxxx>
Signed-off-by: Joe Stringer <joe@xxxxxxx>
---
net/ipv6/netfilter/nf_conntrack_reasm.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index e4347aeb2e65..fd2fda0ae75a 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -595,6 +595,7 @@ int nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 user)
pr_debug("Can't find and can't create new queue\n");
return -ENOMEM;
}
+ skb_orphan(skb);
spin_lock_bh(&fq->q.lock);
--
2.1.4
--
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