RE: kernel stack trace using conntrack

Hi Eric,

The conntrack patch works successfully.

Thanks for your help!

David

-----Message d'origine-----
De : Eric Dumazet [mailto:eric.dumazet@gmail.com]
Envoyé : mardi 16 février 2010 14:45
À : Pablo Neira Ayuso
Cc : Ramblewski David; netfilter-devel@vger.kernel.org; netdev
Objet : Re: kernel stack trace using conntrack

Le mardi 16 février 2010 à 14:33 +0100, Pablo Neira Ayuso a écrit :

Eric Dumazet wrote:

quoted

OK thanks David, I reproduced the problem on latest net-next-2.6 tree
too. I wonder why nobody hit this before.

Hmm, my config had not NETFILTER_DEBUG enabled, that's why I didn't hit
that assertion.

quoted

[352468.556484] ------------[ cut here ]------------
[352468.556511] WARNING: at net/netfilter/nf_conntrack_extend.c:82
__nf_ct_ext_add+0x1c2/0x1e0 [nf_conntrack]()
[352468.556559] Hardware name: ProLiant BL460c G1
[352468.556582] Modules linked in: nf_defrag_ipv4 nf_conntrack_netlink
nf_conntrack sch_hfsc sch_sfq ipmi_devintf ipmi_si ipmi_msghandler hpilo
bonding [last unloaded: nf_conntrack_ipv4]
[352468.556675] Pid: 18852, comm: conntrack Tainted: G        W
2.6.33-rc5-02754-g0ea034c-dirty #545
[352468.556721] Call Trace:
[352468.556742]  [<c054d45f>] ? printk+0x1d/0x26
[352468.556767]  [<c023bbc2>] warn_slowpath_common+0x72/0xa0
[352468.556795]  [<fee75e42>] ? __nf_ct_ext_add+0x1c2/0x1e0
[nf_conntrack]
[352468.556825]  [<fee75e42>] ? __nf_ct_ext_add+0x1c2/0x1e0
[nf_conntrack]
[352468.556854]  [<c023bc0a>] warn_slowpath_null+0x1a/0x20
[352468.556882]  [<fee75e42>] __nf_ct_ext_add+0x1c2/0x1e0 [nf_conntrack]
[352468.556911]  [<fee70dcc>] ? nf_conntrack_alloc+0x10c/0x1a0
[nf_conntrack]
[352468.556940]  [<feecaf59>] ctnetlink_create_conntrack+0x339/0x360
[nf_conntrack_netlink]
[352468.556987]  [<feeca26b>] ? ctnetlink_parse_tuple+0x14b/0x1c0
[nf_conntrack_netlink]
[352468.557039]  [<fee6fd60>] ? __nf_conntrack_find+0x70/0x100
[nf_conntrack]
[352468.557068]  [<feecb090>] ctnetlink_new_conntrack+0x110/0x680
[nf_conntrack_netlink]
[352468.557113]  [<c04d93b5>] nfnetlink_rcv_msg+0x125/0x180
[352468.557140]  [<c054ec57>] ? __mutex_lock_slowpath+0x197/0x230
[352468.557167]  [<c04d9290>] ? nfnetlink_rcv_msg+0x0/0x180
[352468.557194]  [<c04d5896>] netlink_rcv_skb+0x96/0xc0
[352468.557219]  [<c04d927c>] nfnetlink_rcv+0x1c/0x30
[352468.557245]  [<c04d5545>] netlink_unicast+0x255/0x2a0
[352468.557274]  [<c04d5d3f>] netlink_sendmsg+0x1af/0x2b0
[352468.557300]  [<c04a86ec>] sock_sendmsg+0xac/0xe0
[352468.559358]  [<c029d042>] ? find_get_page+0x22/0xd0
[352468.559385]  [<c029d9dc>] ? filemap_fault+0x8c/0x3c0
[352468.559410]  [<c04a905a>] sys_sendto+0xaa/0xd0
[352468.559436]  [<c02b3780>] ? __do_fault+0x370/0x470
[352468.559462]  [<c02b54d9>] ? handle_mm_fault+0x1d9/0x7d0
[352468.559488]  [<c04aa245>] sys_socketcall+0x195/0x280
[352468.559514]  [<c0202c50>] sysenter_do_call+0x12/0x26
[352468.559539] ---[ end trace 6ecb842e4e35a653 ]---

Could you try following patch ?

Thanks

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 0ffe689..d2657aa 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c

@@ -923,7 +923,7 @@ ctnetlink_change_status(struct nf_conn *ct, const struct nlattr * const cda[])
    unsigned int status = ntohl(nla_get_be32(cda[CTA_STATUS]));
    d = ct->status ^ status;

-   if (d & (IPS_EXPECTED|IPS_CONFIRMED|IPS_DYING))
+   if (d & (IPS_EXPECTED|IPS_DYING))
            /* unchangeable */
            return -EBUSY;

I think that we should explicitly report if the user unsets
IPS_CONFIRMED. Please, don't change this.

Apart from that, the patch seems fine to me. Thanks!

Problem is we now (I mean after my patch) enter
ctnetlink_change_status() with ct->status being null (or at least,
IPS_CONFIRMED not set)






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