Patch "openvswitch: Orphan skbs before IPv6 defrag" has been added to the 4.5-stable tree

Patch "openvswitch: Orphan skbs before IPv6 defrag" has been added to the 4.5-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    openvswitch: Orphan skbs before IPv6 defrag

to the 4.5-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     openvswitch-orphan-skbs-before-ipv6-defrag.patch
and it can be found in the queue-4.5 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Mon May 16 11:20:33 PDT 2016
From: Joe Stringer <joe@ovn.org>
Date: Mon, 18 Apr 2016 14:51:47 -0700
Subject: openvswitch: Orphan skbs before IPv6 defrag

From: Joe Stringer <joe@ovn.org>

[ Upstream commit 49e261a8a21e0960a3f7ff187a453ba1c1149053 ]

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@vmware.com>
Signed-off-by: Joe Stringer <joe@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/openvswitch/conntrack.c |    1 +
 1 file changed, 1 insertion(+)

--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -320,6 +320,7 @@ static int handle_fragments(struct net *
 	} 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)


Patches currently in stable-queue which might be from joe@ovn.org are

queue-4.5/openvswitch-orphan-skbs-before-ipv6-defrag.patch