[PATCH v3 10/14] netfilter: Update to register_net_sysctl_sz

[Joel Granados <joel.granados@xxxxxxxxx>]

Move from register_net_sysctl to register_net_sysctl_sz for all the
netfilter related files. Do this while making sure to mirror the NULL
assignments with a table_size of zero for the unprivileged users.

We need to move to the new function in preparation for when we change
SIZE_MAX to ARRAY_SIZE() in the register_net_sysctl macro. Failing to do
so would erroneously allow ARRAY_SIZE() to be called on a pointer. We
hold off the SIZE_MAX to ARRAY_SIZE change until we have migrated all
the relevant net sysctl registering functions to register_net_sysctl_sz
in subsequent commits.

Acked-by: Julian Anastasov <ja@xxxxxx>
Signed-off-by: Joel Granados <j.granados@xxxxxxxxxxx>
---
 net/bridge/br_netfilter_hooks.c         |  3 ++-
 net/ipv6/netfilter/nf_conntrack_reasm.c |  3 ++-
 net/netfilter/ipvs/ip_vs_ctl.c          |  8 ++++++--
 net/netfilter/ipvs/ip_vs_lblc.c         | 10 +++++++---
 net/netfilter/ipvs/ip_vs_lblcr.c        | 10 +++++++---
 net/netfilter/nf_conntrack_standalone.c |  4 +++-
 net/netfilter/nf_log.c                  |  7 ++++---
 7 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c
index 1a801fab9543..15186247b59a 100644
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c
@@ -1135,7 +1135,8 @@ static int br_netfilter_sysctl_init_net(struct net *net)
 
        br_netfilter_sysctl_default(brnet);
 
-       brnet->ctl_hdr = register_net_sysctl(net, "net/bridge", table);
+       brnet->ctl_hdr = register_net_sysctl_sz(net, "net/bridge", table,
+                                               ARRAY_SIZE(brnf_table));
        if (!brnet->ctl_hdr) {
                if (!net_eq(net, &init_net))
                        kfree(table);
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c 
b/net/ipv6/netfilter/nf_conntrack_reasm.c
index d13240f13607..b2dd48911c8d 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -87,7 +87,8 @@ static int nf_ct_frag6_sysctl_register(struct net *net)
        table[2].data   = &nf_frag->fqdir->high_thresh;
        table[2].extra1 = &nf_frag->fqdir->low_thresh;
 
-       hdr = register_net_sysctl(net, "net/netfilter", table);
+       hdr = register_net_sysctl_sz(net, "net/netfilter", table,
+                                    ARRAY_SIZE(nf_ct_frag6_sysctl_table));
        if (hdr == NULL)
                goto err_reg;
 
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 62606fb44d02..8d69e4c2d822 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -4266,6 +4266,7 @@ static int __net_init 
ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs)
        struct net *net = ipvs->net;
        struct ctl_table *tbl;
        int idx, ret;
+       size_t ctl_table_size = ARRAY_SIZE(vs_vars);
 
        atomic_set(&ipvs->dropentry, 0);
        spin_lock_init(&ipvs->dropentry_lock);
@@ -4282,8 +4283,10 @@ static int __net_init 
ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs)
                        return -ENOMEM;
 
                /* Don't export sysctls to unprivileged users */
-               if (net->user_ns != &init_user_ns)
+               if (net->user_ns != &init_user_ns) {
                        tbl[0].procname = NULL;
+                       ctl_table_size = 0;
+               }
        } else
                tbl = vs_vars;
        /* Initialize sysctl defaults */
@@ -4353,7 +4356,8 @@ static int __net_init 
ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs)
 #endif
 
        ret = -ENOMEM;
-       ipvs->sysctl_hdr = register_net_sysctl(net, "net/ipv4/vs", tbl);
+       ipvs->sysctl_hdr = register_net_sysctl_sz(net, "net/ipv4/vs", tbl,
+                                                 ctl_table_size);
        if (!ipvs->sysctl_hdr)
                goto err;
        ipvs->sysctl_tbl = tbl;
diff --git a/net/netfilter/ipvs/ip_vs_lblc.c b/net/netfilter/ipvs/ip_vs_lblc.c
index 1b87214d385e..cf78ba4ce5ff 100644
--- a/net/netfilter/ipvs/ip_vs_lblc.c
+++ b/net/netfilter/ipvs/ip_vs_lblc.c
@@ -550,6 +550,7 @@ static struct ip_vs_scheduler ip_vs_lblc_scheduler = {
 static int __net_init __ip_vs_lblc_init(struct net *net)
 {
        struct netns_ipvs *ipvs = net_ipvs(net);
+       size_t vars_table_size = ARRAY_SIZE(vs_vars_table);
 
        if (!ipvs)
                return -ENOENT;
@@ -562,16 +563,19 @@ static int __net_init __ip_vs_lblc_init(struct net *net)
                        return -ENOMEM;
 
                /* Don't export sysctls to unprivileged users */
-               if (net->user_ns != &init_user_ns)
+               if (net->user_ns != &init_user_ns) {
                        ipvs->lblc_ctl_table[0].procname = NULL;
+                       vars_table_size = 0;
+               }
 
        } else
                ipvs->lblc_ctl_table = vs_vars_table;
        ipvs->sysctl_lblc_expiration = DEFAULT_EXPIRATION;
        ipvs->lblc_ctl_table[0].data = &ipvs->sysctl_lblc_expiration;
 
-       ipvs->lblc_ctl_header =
-               register_net_sysctl(net, "net/ipv4/vs", ipvs->lblc_ctl_table);
+       ipvs->lblc_ctl_header = register_net_sysctl_sz(net, "net/ipv4/vs",
+                                                      ipvs->lblc_ctl_table,
+                                                      vars_table_size);
        if (!ipvs->lblc_ctl_header) {
                if (!net_eq(net, &init_net))
                        kfree(ipvs->lblc_ctl_table);
diff --git a/net/netfilter/ipvs/ip_vs_lblcr.c b/net/netfilter/ipvs/ip_vs_lblcr.c
index ad8f5fea6d3a..9eddf118b40e 100644
--- a/net/netfilter/ipvs/ip_vs_lblcr.c
+++ b/net/netfilter/ipvs/ip_vs_lblcr.c
@@ -736,6 +736,7 @@ static struct ip_vs_scheduler ip_vs_lblcr_scheduler =
 static int __net_init __ip_vs_lblcr_init(struct net *net)
 {
        struct netns_ipvs *ipvs = net_ipvs(net);
+       size_t vars_table_size = ARRAY_SIZE(vs_vars_table);
 
        if (!ipvs)
                return -ENOENT;
@@ -748,15 +749,18 @@ static int __net_init __ip_vs_lblcr_init(struct net *net)
                        return -ENOMEM;
 
                /* Don't export sysctls to unprivileged users */
-               if (net->user_ns != &init_user_ns)
+               if (net->user_ns != &init_user_ns) {
                        ipvs->lblcr_ctl_table[0].procname = NULL;
+                       vars_table_size = 0;
+               }
        } else
                ipvs->lblcr_ctl_table = vs_vars_table;
        ipvs->sysctl_lblcr_expiration = DEFAULT_EXPIRATION;
        ipvs->lblcr_ctl_table[0].data = &ipvs->sysctl_lblcr_expiration;
 
-       ipvs->lblcr_ctl_header =
-               register_net_sysctl(net, "net/ipv4/vs", ipvs->lblcr_ctl_table);
+       ipvs->lblcr_ctl_header = register_net_sysctl_sz(net, "net/ipv4/vs",
+                                                       ipvs->lblcr_ctl_table,
+                                                       vars_table_size);
        if (!ipvs->lblcr_ctl_header) {
                if (!net_eq(net, &init_net))
                        kfree(ipvs->lblcr_ctl_table);
diff --git a/net/netfilter/nf_conntrack_standalone.c 
b/net/netfilter/nf_conntrack_standalone.c
index 169e16fc2bce..0ee98ce5b816 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -1106,7 +1106,9 @@ static int nf_conntrack_standalone_init_sysctl(struct net 
*net)
                table[NF_SYSCTL_CT_BUCKETS].mode = 0444;
        }
 
-       cnet->sysctl_header = register_net_sysctl(net, "net/netfilter", table);
+       cnet->sysctl_header = register_net_sysctl_sz(net, "net/netfilter",
+                                                    table,
+                                                    
ARRAY_SIZE(nf_ct_sysctl_table));
        if (!cnet->sysctl_header)
                goto out_unregister_netfilter;
 
diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index 8a29290149bd..8cc52d2bd31b 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -487,9 +487,10 @@ static int netfilter_log_sysctl_init(struct net *net)
        for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
                table[i].extra2 = net;
 
-       net->nf.nf_log_dir_header = register_net_sysctl(net,
-                                               "net/netfilter/nf_log",
-                                               table);
+       net->nf.nf_log_dir_header = register_net_sysctl_sz(net,
+                                                          
"net/netfilter/nf_log",
+                                                          table,
+                                                          
ARRAY_SIZE(nf_log_sysctl_table));
        if (!net->nf.nf_log_dir_header)
                goto err_reg;
 
-- 
2.30.2