This is a note to let you know that I've just added the patch titled
netfilter: conntrack: fix wrong ct->timeout value
to the 6.3-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:
netfilter-conntrack-fix-wrong-ct-timeout-value.patch
and it can be found in the queue-6.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e47bd80b2a29d1ef74923277662d8329f7480219
Author: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>
Date: Wed Apr 19 13:15:26 2023 +0800
netfilter: conntrack: fix wrong ct->timeout value
[ Upstream commit 73db1b8f2bb6725b7391e85aab41fdf592b3c0c1 ]
(struct nf_conn)->timeout is an interval before the conntrack
confirmed. After confirmed, it becomes a timestamp.
It is observed that timeout of an unconfirmed conntrack:
- Set by calling ctnetlink_change_timeout(). As a result,
`nfct_time_stamp` was wrongly added to `ct->timeout` twice.
- Get by calling ctnetlink_dump_timeout(). As a result,
`nfct_time_stamp` was wrongly subtracted.
Call Trace:
<TASK>
dump_stack_lvl
ctnetlink_dump_timeout
__ctnetlink_glue_build
ctnetlink_glue_build
__nfqnl_enqueue_packet
nf_queue
nf_hook_slow
ip_mc_output
? __pfx_ip_finish_output
ip_send_skb
? __pfx_dst_output
udp_send_skb
udp_sendmsg
? __pfx_ip_generic_getfrag
sock_sendmsg
Separate the 2 cases in:
- Setting `ct->timeout` in __nf_ct_set_timeout().
- Getting `ct->timeout` in ctnetlink_dump_timeout().
Pablo appends:
Update ctnetlink to set up the timeout _after_ the IPS_CONFIRMED flag is
set on, otherwise conntrack creation via ctnetlink breaks.
Note that the problem described in this patch occurs since the
introduction of the nfnetlink_queue conntrack support, select a
sufficiently old Fixes: tag for -stable kernel to pick up this fix.
Fixes: a4b4766c3ceb ("netfilter: nfnetlink_queue: rename related to nfqueue attaching conntrack info")
Signed-off-by: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h
index 71d1269fe4d4f..3384859a89210 100644
--- a/include/net/netfilter/nf_conntrack_core.h
+++ b/include/net/netfilter/nf_conntrack_core.h
@@ -89,7 +89,11 @@ static inline void __nf_ct_set_timeout(struct nf_conn *ct, u64 timeout)
{
if (timeout > INT_MAX)
timeout = INT_MAX;
- WRITE_ONCE(ct->timeout, nfct_time_stamp + (u32)timeout);
+
+ if (nf_ct_is_confirmed(ct))
+ WRITE_ONCE(ct->timeout, nfct_time_stamp + (u32)timeout);
+ else
+ ct->timeout = (u32)timeout;
}
int __nf_ct_change_timeout(struct nf_conn *ct, u64 cta_timeout);
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index d3ee188546982..6f3b23a6653cc 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -176,7 +176,12 @@ static int ctnetlink_dump_status(struct sk_buff *skb, const struct nf_conn *ct)
static int ctnetlink_dump_timeout(struct sk_buff *skb, const struct nf_conn *ct,
bool skip_zero)
{
- long timeout = nf_ct_expires(ct) / HZ;
+ long timeout;
+
+ if (nf_ct_is_confirmed(ct))
+ timeout = nf_ct_expires(ct) / HZ;
+ else
+ timeout = ct->timeout / HZ;
if (skip_zero && timeout == 0)
return 0;
@@ -2253,9 +2258,6 @@ ctnetlink_create_conntrack(struct net *net,
if (!cda[CTA_TIMEOUT])
goto err1;
- timeout = (u64)ntohl(nla_get_be32(cda[CTA_TIMEOUT])) * HZ;
- __nf_ct_set_timeout(ct, timeout);
-
rcu_read_lock();
if (cda[CTA_HELP]) {
char *helpname = NULL;
@@ -2319,6 +2321,9 @@ ctnetlink_create_conntrack(struct net *net,
/* we must add conntrack extensions before confirmation. */
ct->status |= IPS_CONFIRMED;
+ timeout = (u64)ntohl(nla_get_be32(cda[CTA_TIMEOUT])) * HZ;
+ __nf_ct_set_timeout(ct, timeout);
+
if (cda[CTA_STATUS]) {
err = ctnetlink_change_status(ct, cda);
if (err < 0)
