netfilter: evict stale entries when user reads /proc/net/nf_conntrack
Fabian reports a possible conntrack memory leak (could not reproduce so
far), however, one minor issue can be easily resolved:
> cat /proc/net/nf_conntrack | wc -l = 5
> 4 minutes required to clean up the table.
We should not report those timed-out entries to the user in first place.
And instead of just skipping those timed-out entries while iterating over
the table we can also zap them (we already do this during ctnetlink
walks, but I forgot about the /proc interface).
Fixes: f330a7fdbe16 ("netfilter: conntrack: get rid of conntrack timer")
Reported-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 7d52f84..5f446cd 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -212,6 +212,11 @@
if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
return 0;
+ if (nf_ct_should_gc(ct)) {
+ nf_ct_kill(ct);
+ goto release;
+ }
+
/* we only want to print DIR_ORIGINAL */
if (NF_CT_DIRECTION(hash))
goto release;