networking: Update to register_net_sysctl_sz

Joelgranados · mcgrof · commit c899710fe7f9 · 2023-08-15T15:26:18.000-07:00
Move from register_net_sysctl to register_net_sysctl_sz for all the
networking 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.

An additional size function was added to the following files in order to
calculate the size of an array that is defined in another file:
    include/net/ipv6.h
    net/ipv6/icmp.c
    net/ipv6/route.c
    net/ipv6/sysctl_net_ipv6.c

Signed-off-by: Joel Granados &lt;j.granados@samsung.com&gt;
Signed-off-by: Luis Chamberlain &lt;mcgrof@kernel.org&gt;
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
@@ -1274,7 +1274,9 @@ static inline int snmp6_unregister_dev(struct inet6_dev *idev) { return 0; }
 
 #ifdef CONFIG_SYSCTL
 struct ctl_table *ipv6_icmp_sysctl_init(struct net *net);
+size_t ipv6_icmp_sysctl_table_size(void);
 struct ctl_table *ipv6_route_sysctl_init(struct net *net);
+size_t ipv6_route_sysctl_table_size(struct net *net);
 int ipv6_sysctl_register(void);
 void ipv6_sysctl_unregister(void);
 #endif
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
@@ -3779,6 +3779,7 @@ int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
 	const char *dev_name_source;
 	char neigh_path[ sizeof("net//neigh/") + IFNAMSIZ + IFNAMSIZ ];
 	char *p_name;
+	size_t neigh_vars_size;
 
 	t = kmemdup(&neigh_sysctl_template, sizeof(*t), GFP_KERNEL_ACCOUNT);
 	if (!t)
@@ -3790,11 +3791,13 @@ int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
 		t->neigh_vars[i].extra2 = p;
 	}
 
+	neigh_vars_size = ARRAY_SIZE(t->neigh_vars);
 	if (dev) {
 		dev_name_source = dev->name;
 		/* Terminate the table early */
 		memset(&t->neigh_vars[NEIGH_VAR_GC_INTERVAL], 0,
 		       sizeof(t->neigh_vars[NEIGH_VAR_GC_INTERVAL]));
+		neigh_vars_size = NEIGH_VAR_BASE_REACHABLE_TIME_MS + 1;
 	} else {
 		struct neigh_table *tbl = p->tbl;
 		dev_name_source = "default";
@@ -3841,8 +3844,9 @@ int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
 
 	snprintf(neigh_path, sizeof(neigh_path), "net/%s/neigh/%s",
 		p_name, dev_name_source);
-	t->sysctl_header =
-		register_net_sysctl(neigh_parms_net(p), neigh_path, t->neigh_vars);
+	t->sysctl_header = register_net_sysctl_sz(neigh_parms_net(p),
+						  neigh_path, t->neigh_vars,
+						  neigh_vars_size);
 	if (!t->sysctl_header)
 		goto free;
 
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
@@ -712,7 +712,8 @@ static __net_init int sysctl_core_net_init(struct net *net)
 			tmp->data += (char *)net - (char *)&init_net;
 	}
 
-	net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl);
+	net->core.sysctl_hdr = register_net_sysctl_sz(net, "net/core", tbl,
+						      ARRAY_SIZE(netns_core_table));
 	if (net->core.sysctl_hdr == NULL)
 		goto err_reg;
 
diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c
@@ -360,6 +360,7 @@ static int __net_init lowpan_frags_ns_sysctl_register(struct net *net)
 	struct ctl_table_header *hdr;
 	struct netns_ieee802154_lowpan *ieee802154_lowpan =
 		net_ieee802154_lowpan(net);
+	size_t table_size = ARRAY_SIZE(lowpan_frags_ns_ctl_table);
 
 	table = lowpan_frags_ns_ctl_table;
 	if (!net_eq(net, &init_net)) {
@@ -369,8 +370,10 @@ static int __net_init lowpan_frags_ns_sysctl_register(struct net *net)
 			goto err_alloc;
 
 		/* Don't export sysctls to unprivileged users */
-		if (net->user_ns != &init_user_ns)
+		if (net->user_ns != &init_user_ns) {
 			table[0].procname = NULL;
+			table_size = 0;
+		}
 	}
 
 	table[0].data	= &ieee802154_lowpan->fqdir->high_thresh;
@@ -379,7 +382,8 @@ static int __net_init lowpan_frags_ns_sysctl_register(struct net *net)
 	table[1].extra2	= &ieee802154_lowpan->fqdir->high_thresh;
 	table[2].data	= &ieee802154_lowpan->fqdir->timeout;
 
-	hdr = register_net_sysctl(net, "net/ieee802154/6lowpan", table);
+	hdr = register_net_sysctl_sz(net, "net/ieee802154/6lowpan", table,
+				     table_size);
 	if (hdr == NULL)
 		goto err_reg;
 
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
@@ -2720,7 +2720,8 @@ static __net_init int devinet_init_net(struct net *net)
 		goto err_reg_dflt;
 
 	err = -ENOMEM;
-	forw_hdr = register_net_sysctl(net, "net/ipv4", tbl);
+	forw_hdr = register_net_sysctl_sz(net, "net/ipv4", tbl,
+					  ARRAY_SIZE(ctl_forward_entry));
 	if (!forw_hdr)
 		goto err_reg_ctl;
 	net->ipv4.forw_hdr = forw_hdr;
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
@@ -615,7 +615,8 @@ static int __net_init ip4_frags_ns_ctl_register(struct net *net)
 	table[2].data	= &net->ipv4.fqdir->timeout;
 	table[3].data	= &net->ipv4.fqdir->max_dist;
 
-	hdr = register_net_sysctl(net, "net/ipv4", table);
+	hdr = register_net_sysctl_sz(net, "net/ipv4", table,
+				     ARRAY_SIZE(ip4_frags_ns_ctl_table));
 	if (!hdr)
 		goto err_reg;
 
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
@@ -3592,6 +3592,7 @@ static struct ctl_table ipv4_route_netns_table[] = {
 static __net_init int sysctl_route_net_init(struct net *net)
 {
 	struct ctl_table *tbl;
+	size_t table_size = ARRAY_SIZE(ipv4_route_netns_table);
 
 	tbl = ipv4_route_netns_table;
 	if (!net_eq(net, &init_net)) {
@@ -3603,8 +3604,10 @@ static __net_init int sysctl_route_net_init(struct net *net)
 
 		/* Don't export non-whitelisted sysctls to unprivileged users */
 		if (net->user_ns != &init_user_ns) {
-			if (tbl[0].procname != ipv4_route_flush_procname)
+			if (tbl[0].procname != ipv4_route_flush_procname) {
 				tbl[0].procname = NULL;
+				table_size = 0;
+			}
 		}
 
 		/* Update the variables to point into the current struct net
@@ -3615,7 +3618,8 @@ static __net_init int sysctl_route_net_init(struct net *net)
 	}
 	tbl[0].extra1 = net;
 
-	net->ipv4.route_hdr = register_net_sysctl(net, "net/ipv4/route", tbl);
+	net->ipv4.route_hdr = register_net_sysctl_sz(net, "net/ipv4/route",
+						     tbl, table_size);
 	if (!net->ipv4.route_hdr)
 		goto err_reg;
 	return 0;
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
@@ -1519,7 +1519,8 @@ static __net_init int ipv4_sysctl_init_net(struct net *net)
 		}
 	}
 
-	net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table);
+	net->ipv4.ipv4_hdr = register_net_sysctl_sz(net, "net/ipv4", table,
+						    ARRAY_SIZE(ipv4_net_table));
 	if (!net->ipv4.ipv4_hdr)
 		goto err_reg;
 
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
@@ -178,7 +178,8 @@ static __net_init int xfrm4_net_sysctl_init(struct net *net)
 		table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh;
 	}
 
-	hdr = register_net_sysctl(net, "net/ipv4", table);
+	hdr = register_net_sysctl_sz(net, "net/ipv4", table,
+				     ARRAY_SIZE(xfrm4_policy_table));
 	if (!hdr)
 		goto err_reg;
 
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
@@ -7086,7 +7086,8 @@ static int __addrconf_sysctl_register(struct net *net, char *dev_name,
 
 	snprintf(path, sizeof(path), "net/ipv6/conf/%s", dev_name);
 
-	p->sysctl_header = register_net_sysctl(net, path, table);
+	p->sysctl_header = register_net_sysctl_sz(net, path, table,
+						  ARRAY_SIZE(addrconf_sysctl));
 	if (!p->sysctl_header)
 		goto free;
 
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
@@ -1226,4 +1226,9 @@ struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net)
 	}
 	return table;
 }
+
+size_t ipv6_icmp_sysctl_table_size(void)
+{
+	return ARRAY_SIZE(ipv6_icmp_table_template);
+}
 #endif
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
@@ -470,7 +470,8 @@ static int __net_init ip6_frags_ns_sysctl_register(struct net *net)
 	table[1].extra2	= &net->ipv6.fqdir->high_thresh;
 	table[2].data	= &net->ipv6.fqdir->timeout;
 
-	hdr = register_net_sysctl(net, "net/ipv6", table);
+	hdr = register_net_sysctl_sz(net, "net/ipv6", table,
+				     ARRAY_SIZE(ip6_frags_ns_ctl_table));
 	if (!hdr)
 		goto err_reg;
 
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
@@ -6455,6 +6455,15 @@ struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
 
 	return table;
 }
+
+size_t ipv6_route_sysctl_table_size(struct net *net)
+{
+	/* Don't export sysctls to unprivileged users */
+	if (net->user_ns != &init_user_ns)
+		return 1;
+
+	return ARRAY_SIZE(ipv6_route_table_template);
+}
 #endif
 
 static int __net_init ip6_route_net_init(struct net *net)
diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c
@@ -275,17 +275,23 @@ static int __net_init ipv6_sysctl_net_init(struct net *net)
 	if (!ipv6_icmp_table)
 		goto out_ipv6_route_table;
 
-	net->ipv6.sysctl.hdr = register_net_sysctl(net, "net/ipv6", ipv6_table);
+	net->ipv6.sysctl.hdr = register_net_sysctl_sz(net, "net/ipv6",
+						      ipv6_table,
+						      ARRAY_SIZE(ipv6_table_template));
 	if (!net->ipv6.sysctl.hdr)
 		goto out_ipv6_icmp_table;
 
-	net->ipv6.sysctl.route_hdr =
-		register_net_sysctl(net, "net/ipv6/route", ipv6_route_table);
+	net->ipv6.sysctl.route_hdr = register_net_sysctl_sz(net,
+							    "net/ipv6/route",
+							    ipv6_route_table,
+							    ipv6_route_sysctl_table_size(net));
 	if (!net->ipv6.sysctl.route_hdr)
 		goto out_unregister_ipv6_table;
 
-	net->ipv6.sysctl.icmp_hdr =
-		register_net_sysctl(net, "net/ipv6/icmp", ipv6_icmp_table);
+	net->ipv6.sysctl.icmp_hdr = register_net_sysctl_sz(net,
+							   "net/ipv6/icmp",
+							   ipv6_icmp_table,
+							   ipv6_icmp_sysctl_table_size());
 	if (!net->ipv6.sysctl.icmp_hdr)
 		goto out_unregister_route_table;
 
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
@@ -205,7 +205,8 @@ static int __net_init xfrm6_net_sysctl_init(struct net *net)
 		table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh;
 	}
 
-	hdr = register_net_sysctl(net, "net/ipv6", table);
+	hdr = register_net_sysctl_sz(net, "net/ipv6", table,
+				     ARRAY_SIZE(xfrm6_policy_table));
 	if (!hdr)
 		goto err_reg;
 
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
@@ -1419,7 +1419,8 @@ static int mpls_dev_sysctl_register(struct net_device *dev,
 
 	snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
 
-	mdev->sysctl = register_net_sysctl(net, path, table);
+	mdev->sysctl = register_net_sysctl_sz(net, path, table,
+					      ARRAY_SIZE(mpls_dev_table));
 	if (!mdev->sysctl)
 		goto free;
 
@@ -2689,7 +2690,8 @@ static int mpls_net_init(struct net *net)
 	for (i = 0; i < ARRAY_SIZE(mpls_table) - 1; i++)
 		table[i].data = (char *)net + (uintptr_t)table[i].data;
 
-	net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
+	net->mpls.ctl = register_net_sysctl_sz(net, "net/mpls", table,
+					       ARRAY_SIZE(mpls_table));
 	if (net->mpls.ctl == NULL) {
 		kfree(table);
 		return -ENOMEM;
diff --git a/net/mptcp/ctrl.c b/net/mptcp/ctrl.c
@@ -150,7 +150,8 @@ static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
 	table[4].data = &pernet->stale_loss_cnt;
 	table[5].data = &pernet->pm_type;
 
-	hdr = register_net_sysctl(net, MPTCP_SYSCTL_PATH, table);
+	hdr = register_net_sysctl_sz(net, MPTCP_SYSCTL_PATH, table,
+				     ARRAY_SIZE(mptcp_sysctl_table));
 	if (!hdr)
 		goto err_reg;
 
diff --git a/net/rds/tcp.c b/net/rds/tcp.c
@@ -565,7 +565,8 @@ static __net_init int rds_tcp_init_net(struct net *net)
 	}
 	tbl[RDS_TCP_SNDBUF].data = &rtn->sndbuf_size;
 	tbl[RDS_TCP_RCVBUF].data = &rtn->rcvbuf_size;
-	rtn->rds_tcp_sysctl = register_net_sysctl(net, "net/rds/tcp", tbl);
+	rtn->rds_tcp_sysctl = register_net_sysctl_sz(net, "net/rds/tcp", tbl,
+						     ARRAY_SIZE(rds_tcp_sysctl_table));
 	if (!rtn->rds_tcp_sysctl) {
 		pr_warn("could not register sysctl\n");
 		err = -ENOMEM;
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
@@ -612,7 +612,9 @@ int sctp_sysctl_net_register(struct net *net)
 	table[SCTP_PF_RETRANS_IDX].extra2 = &net->sctp.ps_retrans;
 	table[SCTP_PS_RETRANS_IDX].extra1 = &net->sctp.pf_retrans;
 
-	net->sctp.sysctl_header = register_net_sysctl(net, "net/sctp", table);
+	net->sctp.sysctl_header = register_net_sysctl_sz(net, "net/sctp",
+							 table,
+							 ARRAY_SIZE(sctp_net_table));
 	if (net->sctp.sysctl_header == NULL) {
 		kfree(table);
 		return -ENOMEM;
diff --git a/net/smc/smc_sysctl.c b/net/smc/smc_sysctl.c
@@ -81,7 +81,8 @@ int __net_init smc_sysctl_net_init(struct net *net)
 			table[i].data += (void *)net - (void *)&init_net;
 	}
 
-	net->smc.smc_hdr = register_net_sysctl(net, "net/smc", table);
+	net->smc.smc_hdr = register_net_sysctl_sz(net, "net/smc", table,
+						  ARRAY_SIZE(smc_table));
 	if (!net->smc.smc_hdr)
 		goto err_reg;
 
diff --git a/net/unix/sysctl_net_unix.c b/net/unix/sysctl_net_unix.c
@@ -36,7 +36,8 @@ int __net_init unix_sysctl_register(struct net *net)
 		table[0].data = &net->unx.sysctl_max_dgram_qlen;
 	}
 
-	net->unx.ctl = register_net_sysctl(net, "net/unix", table);
+	net->unx.ctl = register_net_sysctl_sz(net, "net/unix", table,
+					      ARRAY_SIZE(unix_table));
 	if (net->unx.ctl == NULL)
 		goto err_reg;
 
diff --git a/net/xfrm/xfrm_sysctl.c b/net/xfrm/xfrm_sysctl.c
@@ -44,6 +44,7 @@ static struct ctl_table xfrm_table[] = {
 int __net_init xfrm_sysctl_init(struct net *net)
 {
 	struct ctl_table *table;
+	size_t table_size = ARRAY_SIZE(xfrm_table);
 
 	__xfrm_sysctl_init(net);
 
@@ -56,10 +57,13 @@ int __net_init xfrm_sysctl_init(struct net *net)
 	table[3].data = &net->xfrm.sysctl_acq_expires;
 
 	/* Don't export sysctls to unprivileged users */
-	if (net->user_ns != &init_user_ns)
+	if (net->user_ns != &init_user_ns) {
 		table[0].procname = NULL;
+		table_size = 0;
+	}
 
-	net->xfrm.sysctl_hdr = register_net_sysctl(net, "net/core", table);
+	net->xfrm.sysctl_hdr = register_net_sysctl_sz(net, "net/core", table,
+						      table_size);
 	if (!net->xfrm.sysctl_hdr)
 		goto out_register;
 	return 0;

Original file line number	Diff line number	Diff line change
`@@ -712,7 +712,8 @@ static __net_init int sysctl_core_net_init(struct net *net)`
`712`	`712`	`tmp->data += (char )net - (char )&init_net;`
`713`	`713`	`}`
`714`	`714`
`715`		`- net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl);`
	`715`	`+ net->core.sysctl_hdr = register_net_sysctl_sz(net, "net/core", tbl,`
	`716`	`+ ARRAY_SIZE(netns_core_table));`
`716`	`717`	`if (net->core.sysctl_hdr == NULL)`
`717`	`718`	`goto err_reg;`
`718`	`719`
Original file line number	Diff line number	Diff line change
`@@ -1519,7 +1519,8 @@ static __net_init int ipv4_sysctl_init_net(struct net *net)`
`1519`	`1519`	`}`
`1520`	`1520`	`}`
`1521`	`1521`
`1522`		`- net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table);`
	`1522`	`+ net->ipv4.ipv4_hdr = register_net_sysctl_sz(net, "net/ipv4", table,`
	`1523`	`+ ARRAY_SIZE(ipv4_net_table));`
`1523`	`1524`	`if (!net->ipv4.ipv4_hdr)`
`1524`	`1525`	`goto err_reg;`
`1525`	`1526`
Original file line number	Diff line number	Diff line change
`@@ -178,7 +178,8 @@ static __net_init int xfrm4_net_sysctl_init(struct net *net)`
`178`	`178`	`table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh;`
`179`	`179`	`}`
`180`	`180`
`181`		`- hdr = register_net_sysctl(net, "net/ipv4", table);`
	`181`	`+ hdr = register_net_sysctl_sz(net, "net/ipv4", table,`
	`182`	`+ ARRAY_SIZE(xfrm4_policy_table));`
`182`	`183`	`if (!hdr)`
`183`	`184`	`goto err_reg;`
`184`	`185`