[ 3.5.yuz extended stable ] Patch "netfilter: nf_nat_sip: fix incorrect handling of EBUSY for" has been added to staging queue

[Herton Ronaldo Krzesinski]

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

    netfilter: nf_nat_sip: fix incorrect handling of EBUSY for

to the linux-3.5.y-queue branch of the 3.5.yuz extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

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

For more information about the 3.5.yuz tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

>From 3a2eea078ed40428beaa609b0cf31e42cd8ff3c3 Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo at netfilter.org>
Date: Wed, 29 Aug 2012 15:24:09 +0000
Subject: [PATCH] netfilter: nf_nat_sip: fix incorrect handling of EBUSY for
 RTCP expectation

commit 3f509c689a07a4aa989b426893d8491a7ffcc410 upstream.

We're hitting bug while trying to reinsert an already existing
expectation:

kernel BUG at kernel/timer.c:895!
invalid opcode: 0000 [#1] SMP
[...]
Call Trace:
 <IRQ>
 [<ffffffffa0069563>] nf_ct_expect_related_report+0x4a0/0x57a [nf_conntrack]
 [<ffffffff812d423a>] ? in4_pton+0x72/0x131
 [<ffffffffa00ca69e>] ip_nat_sdp_media+0xeb/0x185 [nf_nat_sip]
 [<ffffffffa00b5b9b>] set_expected_rtp_rtcp+0x32d/0x39b [nf_conntrack_sip]
 [<ffffffffa00b5f15>] process_sdp+0x30c/0x3ec [nf_conntrack_sip]
 [<ffffffff8103f1eb>] ? irq_exit+0x9a/0x9c
 [<ffffffffa00ca738>] ? ip_nat_sdp_media+0x185/0x185 [nf_nat_sip]

We have to remove the RTP expectation if the RTCP expectation hits EBUSY
since we keep trying with other ports until we succeed.

Reported-by: Rafal Fitt <rafalf at aplusc.com.pl>
Signed-off-by: Pablo Neira Ayuso <pablo at netfilter.org>
Acked-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 net/ipv4/netfilter/nf_nat_sip.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
index ea4a238..bb71caa 100644
--- a/net/ipv4/netfilter/nf_nat_sip.c
+++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -501,7 +501,10 @@ static unsigned int ip_nat_sdp_media(struct sk_buff *skb, unsigned int dataoff,
 		ret = nf_ct_expect_related(rtcp_exp);
 		if (ret == 0)
 			break;
-		else if (ret != -EBUSY) {
+		else if (ret == -EBUSY) {
+			nf_ct_unexpect_related(rtp_exp);
+			continue;
+		} else if (ret < 0) {
 			nf_ct_unexpect_related(rtp_exp);
 			port = 0;
 			break;
--
1.7.9.5