[ 3.8.y.z extended stable ] Patch "ipv6: in case of link failure remove route directly instead of" has been added to staging queue

Kamal Mostafa kamal at canonical.com
Fri Jul 26 00:24:09 UTC 2013


This is a note to let you know that I have just added a patch titled

    ipv6: in case of link failure remove route directly instead of

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.6.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 9e7a574be8cc8e49dc3c990d2c3c14d692391ef9 Mon Sep 17 00:00:00 2001
From: Hannes Frederic Sowa <hannes at stressinduktion.org>
Date: Wed, 10 Jul 2013 23:00:57 +0200
Subject: ipv6: in case of link failure remove route directly instead of
 letting it expire

[ Upstream commit 1eb4f758286884e7566627164bca4c4a16952a83 ]

We could end up expiring a route which is part of an ecmp route set. Doing
so would invalidate the rt->rt6i_nsiblings calculations and could provoke
the following panic:

[   80.144667] ------------[ cut here ]------------
[   80.145172] kernel BUG at net/ipv6/ip6_fib.c:733!
[   80.145172] invalid opcode: 0000 [#1] SMP
[   80.145172] Modules linked in: 8021q nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6table_mangle ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 iptable_nat nf_nat_ipv4 nf_nat iptable_mangle nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ebtable_filter ebtables ip6table_filter ip6_tables
+snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm snd_page_alloc snd_timer virtio_balloon snd soundcore i2c_piix4 i2c_core virtio_net virtio_blk
[   80.145172] CPU: 1 PID: 786 Comm: ping6 Not tainted 3.10.0+ #118
[   80.145172] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   80.145172] task: ffff880117fa0000 ti: ffff880118770000 task.ti: ffff880118770000
[   80.145172] RIP: 0010:[<ffffffff815f3b5d>]  [<ffffffff815f3b5d>] fib6_add+0x75d/0x830
[   80.145172] RSP: 0018:ffff880118771798  EFLAGS: 00010202
[   80.145172] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88011350e480
[   80.145172] RDX: ffff88011350e238 RSI: 0000000000000004 RDI: ffff88011350f738
[   80.145172] RBP: ffff880118771848 R08: ffff880117903280 R09: 0000000000000001
[   80.145172] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88011350f680
[   80.145172] R13: ffff880117903280 R14: ffff880118771890 R15: ffff88011350ef90
[   80.145172] FS:  00007f02b5127740(0000) GS:ffff88011fd00000(0000) knlGS:0000000000000000
[   80.145172] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[   80.145172] CR2: 00007f981322a000 CR3: 00000001181b1000 CR4: 00000000000006e0
[   80.145172] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   80.145172] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[   80.145172] Stack:
[   80.145172]  0000000000000001 ffff880100000000 ffff880100000000 ffff880117903280
[   80.145172]  0000000000000000 ffff880119a4cf00 0000000000000400 00000000000007fa
[   80.145172]  0000000000000000 0000000000000000 0000000000000000 ffff88011350f680
[   80.145172] Call Trace:
[   80.145172]  [<ffffffff815eeceb>] ? rt6_bind_peer+0x4b/0x90
[   80.145172]  [<ffffffff815ed985>] __ip6_ins_rt+0x45/0x70
[   80.145172]  [<ffffffff815eee35>] ip6_ins_rt+0x35/0x40
[   80.145172]  [<ffffffff815ef1e4>] ip6_pol_route.isra.44+0x3a4/0x4b0
[   80.145172]  [<ffffffff815ef34a>] ip6_pol_route_output+0x2a/0x30
[   80.145172]  [<ffffffff81616077>] fib6_rule_action+0xd7/0x210
[   80.145172]  [<ffffffff815ef320>] ? ip6_pol_route_input+0x30/0x30
[   80.145172]  [<ffffffff81553026>] fib_rules_lookup+0xc6/0x140
[   80.145172]  [<ffffffff81616374>] fib6_rule_lookup+0x44/0x80
[   80.145172]  [<ffffffff815ef320>] ? ip6_pol_route_input+0x30/0x30
[   80.145172]  [<ffffffff815edea3>] ip6_route_output+0x73/0xb0
[   80.145172]  [<ffffffff815dfdf3>] ip6_dst_lookup_tail+0x2c3/0x2e0
[   80.145172]  [<ffffffff813007b1>] ? list_del+0x11/0x40
[   80.145172]  [<ffffffff81082a4c>] ? remove_wait_queue+0x3c/0x50
[   80.145172]  [<ffffffff815dfe4d>] ip6_dst_lookup_flow+0x3d/0xa0
[   80.145172]  [<ffffffff815fda77>] rawv6_sendmsg+0x267/0xc20
[   80.145172]  [<ffffffff815a8a83>] inet_sendmsg+0x63/0xb0
[   80.145172]  [<ffffffff8128eb93>] ? selinux_socket_sendmsg+0x23/0x30
[   80.145172]  [<ffffffff815218d6>] sock_sendmsg+0xa6/0xd0
[   80.145172]  [<ffffffff81524a68>] SYSC_sendto+0x128/0x180
[   80.145172]  [<ffffffff8109825c>] ? update_curr+0xec/0x170
[   80.145172]  [<ffffffff81041d09>] ? kvm_clock_get_cycles+0x9/0x10
[   80.145172]  [<ffffffff810afd1e>] ? __getnstimeofday+0x3e/0xd0
[   80.145172]  [<ffffffff8152509e>] SyS_sendto+0xe/0x10
[   80.145172]  [<ffffffff8164efd9>] system_call_fastpath+0x16/0x1b
[   80.145172] Code: fe ff ff 41 f6 45 2a 06 0f 85 ca fe ff ff 49 8b 7e 08 4c 89 ee e8 94 ef ff ff e9 b9 fe ff ff 48 8b 82 28 05 00 00 e9 01 ff ff ff <0f> 0b 49 8b 54 24 30 0d 00 00 40 00 89 83 14 01 00 00 48 89 53
[   80.145172] RIP  [<ffffffff815f3b5d>] fib6_add+0x75d/0x830
[   80.145172]  RSP <ffff880118771798>
[   80.387413] ---[ end trace 02f20b7a8b81ed95 ]---
[   80.390154] Kernel panic - not syncing: Fatal exception in interrupt

Cc: Nicolas Dichtel <nicolas.dichtel at 6wind.com>
Cc: YOSHIFUJI Hideaki <yoshfuji at linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes at stressinduktion.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/ipv6/route.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 5845613..2f01ab3 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1118,10 +1118,13 @@ static void ip6_link_failure(struct sk_buff *skb)

 	rt = (struct rt6_info *) skb_dst(skb);
 	if (rt) {
-		if (rt->rt6i_flags & RTF_CACHE)
-			rt6_update_expires(rt, 0);
-		else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT))
+		if (rt->rt6i_flags & RTF_CACHE) {
+			dst_hold(&rt->dst);
+			if (ip6_del_rt(rt))
+				dst_free(&rt->dst);
+		} else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT)) {
 			rt->rt6i_node->fn_sernum = -1;
+		}
 	}
 }

--
1.8.1.2





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