[PATCH nf] netfilter: conntrack: adjust stop timestamp to real expiry value

[PATCH nf] netfilter: conntrack: adjust stop timestamp to real expiry value

[Florian Westphal]

In case the entry is evicted via garbage collection there is
delay between the timeout value and the eviction event.

This adjusts the stop value based on how much time has passed.

Fixes: b87a2f9199ea82 ("netfilter: conntrack: add gc worker to remove timed-out entries")
Signed-off-by: Florian Westphal <fw@strlen.de>
---
 net/netfilter/nf_conntrack_core.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 96ba19fc8155..97274698050b 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -662,8 +662,13 @@ bool nf_ct_delete(struct nf_conn *ct, u32 portid, int report)
 		return false;
 
 	tstamp = nf_conn_tstamp_find(ct);
-	if (tstamp && tstamp->stop == 0)
+	if (tstamp) {
+		s32 timeout = ct->timeout - nfct_time_stamp;
+
 		tstamp->stop = ktime_get_real_ns();
+		if (timeout < 0)
+			tstamp->stop -= jiffies_to_nsecs(-timeout);
+	}
 
 	if (nf_conntrack_event_report(IPCT_DESTROY, ct,
 				    portid, report) < 0) {
-- 
2.31.1

Re: [PATCH nf] netfilter: conntrack: adjust stop timestamp to real expiry value

[Pablo Neira Ayuso]

On Sun, Jul 18, 2021 at 06:36:00PM +0200, Florian Westphal wrote:
> In case the entry is evicted via garbage collection there is
> delay between the timeout value and the eviction event.
> 
> This adjusts the stop value based on how much time has passed.

Applied, thanks.