2006-11-16 10:47:57

by Faidon Liambotis

Subject: [PATCH 2.6.19-rc6] netfilter: fix panic on ip_conntrack_h323 with CONFIG_IP_NF_CT_ACCT

H.323 connection tracking code calls ip_ct_refresh_acct() when
processing RCFs and URQs but passes NULL as the skb.
When CONFIG_IP_NF_CT_ACCT is enabled, the connection tracking core tries
to derefence the skb, which results in an obvious panic.
A similar fix was applied on the SIP connection tracking code some time
ago.

Signed-off-by: Faidon Liambotis <[email protected]>

--- a/net/ipv4/netfilter/ip_conntrack_helper_h323.c 2006-11-15 19:07:50.000000000 +0200
+++ b/net/ipv4/netfilter/ip_conntrack_helper_h323.c 2006-11-16 11:09:46.000000000 +0200
@@ -1417,7 +1417,7 @@ static int process_rcf(struct sk_buff **
DEBUGP
("ip_ct_ras: set RAS connection timeout to %u seconds\n",
info->timeout);
- ip_ct_refresh_acct(ct, ctinfo, NULL, info->timeout * HZ);
+ ip_ct_refresh_acct(ct, ctinfo, *pskb, info->timeout * HZ);

/* Set expect timeout */
read_lock_bh(&ip_conntrack_lock);
@@ -1465,7 +1465,7 @@ static int process_urq(struct sk_buff **
info->sig_port[!dir] = 0;

/* Give it 30 seconds for UCF or URJ */
- ip_ct_refresh_acct(ct, ctinfo, NULL, 30 * HZ);
+ ip_ct_refresh_acct(ct, ctinfo, *pskb, 30 * HZ);

return 0;
}

2006-11-16 11:30:09

by Patrick McHardy

Subject: Re: [netfilter-core] [PATCH 2.6.19-rc6] netfilter: fix panic on ip_conntrack_h323 with CONFIG_IP_NF_CT_ACCT

Faidon Liambotis wrote:
> H.323 connection tracking code calls ip_ct_refresh_acct() when
> processing RCFs and URQs but passes NULL as the skb.
> When CONFIG_IP_NF_CT_ACCT is enabled, the connection tracking core tries
> to derefence the skb, which results in an obvious panic.
> A similar fix was applied on the SIP connection tracking code some time
> ago.

Good catch, but the fix is wrong and will lead to double accounting
of the skb. The correct fix is to use ip_ct_refresh() instead,
which only updates the timeout. Can you send a new patch please?

> Signed-off-by: Faidon Liambotis <[email protected]>
>
> --- a/net/ipv4/netfilter/ip_conntrack_helper_h323.c 2006-11-15 19:07:50.000000000 +0200
> +++ b/net/ipv4/netfilter/ip_conntrack_helper_h323.c 2006-11-16 11:09:46.000000000 +0200
> @@ -1417,7 +1417,7 @@ static int process_rcf(struct sk_buff **
> DEBUGP
> ("ip_ct_ras: set RAS connection timeout to %u seconds\n",
> info->timeout);
> - ip_ct_refresh_acct(ct, ctinfo, NULL, info->timeout * HZ);
> + ip_ct_refresh_acct(ct, ctinfo, *pskb, info->timeout * HZ);
>
> /* Set expect timeout */
> read_lock_bh(&ip_conntrack_lock);
> @@ -1465,7 +1465,7 @@ static int process_urq(struct sk_buff **
> info->sig_port[!dir] = 0;
>
> /* Give it 30 seconds for UCF or URJ */
> - ip_ct_refresh_acct(ct, ctinfo, NULL, 30 * HZ);
> + ip_ct_refresh_acct(ct, ctinfo, *pskb, 30 * HZ);
>
> return 0;
> }
>