This prevents the modification of nf_conntrack_max in unprivileged network
namespaces. For unprivileged network namespaces, ip_conntrack_max is kept
as a readonly sysctl in order to minimize potential compatibility issues.
This patch should apply cleanly to the net tree.
Signed-off-by: Jann Horn <j...@thejh.net>
---
net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index ae1a71a..a639e94 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -358,6 +358,9 @@ static int ipv4_init_net(struct net *net)
if (!in->ctl_table)
return -ENOMEM;
+ if (net->user_ns != &init_user_ns)
+ in->ctl_table[0].mode = 0444;
+
in->ctl_table[0].data = &nf_conntrack_max;
in->ctl_table[1].data = &net->ct.count;
in->ctl_table[2].data = &nf_conntrack_htable_size;
--
2.1.4
