[PATCH 4.19 07/37] netfilter: ipvs: make global sysctl readonly in non-init netns

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Antoine Tenart <atenart@kernel.org>

[ Upstream commit 174c376278949c44aad89c514a6b5db6cee8db59 ]

Because the data pointer of net/ipv4/vs/debug_level is not updated per
netns, it must be marked as read-only in non-init netns.

Fixes: c6d2d445d8de ("IPVS: netns, final patch enabling network name space.")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netfilter/ipvs/ip_vs_ctl.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 6208fa09fe71..3bf8d7f3cdc3 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -3955,6 +3955,11 @@ static int __net_init ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs)
 	tbl[idx++].data = &ipvs->sysctl_conn_reuse_mode;
 	tbl[idx++].data = &ipvs->sysctl_schedule_icmp;
 	tbl[idx++].data = &ipvs->sysctl_ignore_tunneled;
+#ifdef CONFIG_IP_VS_DEBUG
+	/* Global sysctls must be ro in non-init netns */
+	if (!net_eq(net, &init_net))
+		tbl[idx++].mode = 0444;
+#endif
 
 	ipvs->sysctl_hdr = register_net_sysctl(net, "net/ipv4/vs", tbl);
 	if (ipvs->sysctl_hdr == NULL) {
-- 
2.33.0