sysctl: pass kernel pointers to ->proc_handler

Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from  userspace in common code.  This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.

As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

21 files changed, 109 insertions, 168 deletions

diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c
index 59980ecfc962..04c3f9a82650 100644
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c
@@ -1027,7 +1027,7 @@ int br_nf_hook_thresh(unsigned int hook, struct net *net,
 #ifdef CONFIG_SYSCTL
 static
 int brnf_sysctl_call_tables(struct ctl_table *ctl, int write,
-			    void __user *buffer, size_t *lenp, loff_t *ppos)
+			    void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 39d37d0ef575..3f2263e79e4b 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -3379,7 +3379,7 @@ EXPORT_SYMBOL(neigh_app_ns);
 static int unres_qlen_max = INT_MAX / SKB_TRUESIZE(ETH_FRAME_LEN);
 
 static int proc_unres_qlen(struct ctl_table *ctl, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
+			   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int size, ret;
 	struct ctl_table tmp = *ctl;
@@ -3443,8 +3443,8 @@ static void neigh_proc_update(struct ctl_table *ctl, int write)
 }
 
 static int neigh_proc_dointvec_zero_intmax(struct ctl_table *ctl, int write,
-					   void __user *buffer,
-					   size_t *lenp, loff_t *ppos)
+					   void *buffer, size_t *lenp,
+					   loff_t *ppos)
 {
 	struct ctl_table tmp = *ctl;
 	int ret;
@@ -3457,8 +3457,8 @@ static int neigh_proc_dointvec_zero_intmax(struct ctl_table *ctl, int write,
 	return ret;
 }
 
-int neigh_proc_dointvec(struct ctl_table *ctl, int write,
-			void __user *buffer, size_t *lenp, loff_t *ppos)
+int neigh_proc_dointvec(struct ctl_table *ctl, int write, void *buffer,
+			size_t *lenp, loff_t *ppos)
 {
 	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
 
@@ -3467,8 +3467,7 @@ int neigh_proc_dointvec(struct ctl_table *ctl, int write,
 }
 EXPORT_SYMBOL(neigh_proc_dointvec);
 
-int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
-				void __user *buffer,
+int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write, void *buffer,
 				size_t *lenp, loff_t *ppos)
 {
 	int ret = proc_dointvec_jiffies(ctl, write, buffer, lenp, ppos);
@@ -3479,8 +3478,8 @@ int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write,
 EXPORT_SYMBOL(neigh_proc_dointvec_jiffies);
 
 static int neigh_proc_dointvec_userhz_jiffies(struct ctl_table *ctl, int write,
-					      void __user *buffer,
-					      size_t *lenp, loff_t *ppos)
+					      void *buffer, size_t *lenp,
+					      loff_t *ppos)
 {
 	int ret = proc_dointvec_userhz_jiffies(ctl, write, buffer, lenp, ppos);
 
@@ -3489,8 +3488,7 @@ static int neigh_proc_dointvec_userhz_jiffies(struct ctl_table *ctl, int write,
 }
 
 int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
-				   void __user *buffer,
-				   size_t *lenp, loff_t *ppos)
+				   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret = proc_dointvec_ms_jiffies(ctl, write, buffer, lenp, ppos);
 
@@ -3500,8 +3498,8 @@ int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write,
 EXPORT_SYMBOL(neigh_proc_dointvec_ms_jiffies);
 
 static int neigh_proc_dointvec_unres_qlen(struct ctl_table *ctl, int write,
-					  void __user *buffer,
-					  size_t *lenp, loff_t *ppos)
+					  void *buffer, size_t *lenp,
+					  loff_t *ppos)
 {
 	int ret = proc_unres_qlen(ctl, write, buffer, lenp, ppos);
 
@@ -3510,8 +3508,8 @@ static int neigh_proc_dointvec_unres_qlen(struct ctl_table *ctl, int write,
 }
 
 static int neigh_proc_base_reachable_time(struct ctl_table *ctl, int write,
-					  void __user *buffer,
-					  size_t *lenp, loff_t *ppos)
+					  void *buffer, size_t *lenp,
+					  loff_t *ppos)
 {
 	struct neigh_parms *p = ctl->extra2;
 	int ret;
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
index 9f9e00ba3ad7..0ddb13a6282b 100644
--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c
@@ -45,7 +45,7 @@ EXPORT_SYMBOL(sysctl_devconf_inherit_init_net);
 
 #ifdef CONFIG_RPS
 static int rps_sock_flow_sysctl(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	unsigned int orig_size, size;
 	int ret, i;
@@ -115,8 +115,7 @@ static int rps_sock_flow_sysctl(struct ctl_table *table, int write,
 static DEFINE_MUTEX(flow_limit_update_mutex);
 
 static int flow_limit_cpu_sysctl(struct ctl_table *table, int write,
-				 void __user *buffer, size_t *lenp,
-				 loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct sd_flow_limit *cur;
 	struct softnet_data *sd;
@@ -180,10 +179,7 @@ write_unlock:
 		}
 		if (len < *lenp)
 			kbuf[len++] = '\n';
-		if (copy_to_user(buffer, kbuf, len)) {
-			ret = -EFAULT;
-			goto done;
-		}
+		memcpy(buffer, kbuf, len);
 		*lenp = len;
 		*ppos += len;
 	}
@@ -194,8 +190,7 @@ done:
 }
 
 static int flow_limit_table_len_sysctl(struct ctl_table *table, int write,
-				       void __user *buffer, size_t *lenp,
-				       loff_t *ppos)
+				       void *buffer, size_t *lenp, loff_t *ppos)
 {
 	unsigned int old, *ptr;
 	int ret;
@@ -217,7 +212,7 @@ static int flow_limit_table_len_sysctl(struct ctl_table *table, int write,
 
 #ifdef CONFIG_NET_SCHED
 static int set_default_qdisc(struct ctl_table *table, int write,
-			     void __user *buffer, size_t *lenp, loff_t *ppos)
+			     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	char id[IFNAMSIZ];
 	struct ctl_table tbl = {
@@ -236,7 +231,7 @@ static int set_default_qdisc(struct ctl_table *table, int write,
 #endif
 
 static int proc_do_dev_weight(struct ctl_table *table, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
+			   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 
@@ -251,7 +246,7 @@ static int proc_do_dev_weight(struct ctl_table *table, int write,
 }
 
 static int proc_do_rss_key(struct ctl_table *table, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
+			   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table fake_table;
 	char buf[NETDEV_RSS_KEY_LEN * 3];
@@ -264,7 +259,7 @@ static int proc_do_rss_key(struct ctl_table *table, int write,
 
 #ifdef CONFIG_BPF_JIT
 static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write,
-					   void __user *buffer, size_t *lenp,
+					   void *buffer, size_t *lenp,
 					   loff_t *ppos)
 {
 	int ret, jit_enable = *(int *)table->data;
@@ -291,8 +286,7 @@ static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write,
 # ifdef CONFIG_HAVE_EBPF_JIT
 static int
 proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write,
-				    void __user *buffer, size_t *lenp,
-				    loff_t *ppos)
+				    void *buffer, size_t *lenp, loff_t *ppos)
 {
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
@@ -303,8 +297,7 @@ proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write,
 
 static int
 proc_dolongvec_minmax_bpf_restricted(struct ctl_table *table, int write,
-				     void __user *buffer, size_t *lenp,
-				     loff_t *ppos)
+				     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index cca7ae712995..65abcf1b3210 100644
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -160,8 +160,8 @@ static int max_t3[] = { 8191 }; /* Must fit in 16 bits when multiplied by BCT3MU
 static int min_priority[1];
 static int max_priority[] = { 127 }; /* From DECnet spec */
 
-static int dn_forwarding_proc(struct ctl_table *, int,
-			void __user *, size_t *, loff_t *);
+static int dn_forwarding_proc(struct ctl_table *, int, void *, size_t *,
+		loff_t *);
 static struct dn_dev_sysctl_table {
 	struct ctl_table_header *sysctl_header;
 	struct ctl_table dn_dev_vars[5];
@@ -245,8 +245,7 @@ static void dn_dev_sysctl_unregister(struct dn_dev_parms *parms)
 }
 
 static int dn_forwarding_proc(struct ctl_table *table, int write,
-				void __user *buffer,
-				size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 #ifdef CONFIG_DECNET_ROUTER
 	struct net_device *dev = table->extra1;
diff --git a/net/decnet/sysctl_net_decnet.c b/net/decnet/sysctl_net_decnet.c
index 55bf64a22b59..deae519bdeec 100644
--- a/net/decnet/sysctl_net_decnet.c
+++ b/net/decnet/sysctl_net_decnet.c
@@ -134,8 +134,7 @@ static int parse_addr(__le16 *addr, char *str)
 }
 
 static int dn_node_address_handler(struct ctl_table *table, int write,
-				void __user *buffer,
-				size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	char addr[DN_ASCBUF_LEN];
 	size_t len;
@@ -148,10 +147,7 @@ static int dn_node_address_handler(struct ctl_table *table, int write,
 
 	if (write) {
 		len = (*lenp < DN_ASCBUF_LEN) ? *lenp : (DN_ASCBUF_LEN-1);
-
-		if (copy_from_user(addr, buffer, len))
-			return -EFAULT;
-
+		memcpy(addr, buffer, len);
 		addr[len] = 0;
 		strip_it(addr);
 
@@ -173,11 +169,9 @@ static int dn_node_address_handler(struct ctl_table *table, int write,
 	len = strlen(addr);
 	addr[len++] = '\n';
 
-	if (len > *lenp) len = *lenp;
-
-	if (copy_to_user(buffer, addr, len))
-		return -EFAULT;
-
+	if (len > *lenp)
+		len = *lenp;
+	memcpy(buffer, addr, len);
 	*lenp = len;
 	*ppos += len;
 
@@ -185,8 +179,7 @@ static int dn_node_address_handler(struct ctl_table *table, int write,
 }
 
 static int dn_def_dev_handler(struct ctl_table *table, int write,
-				void __user *buffer,
-				size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	size_t len;
 	struct net_device *dev;
@@ -201,9 +194,7 @@ static int dn_def_dev_handler(struct ctl_table *table, int write,
 		if (*lenp > 16)
 			return -E2BIG;
 
-		if (copy_from_user(devname, buffer, *lenp))
-			return -EFAULT;
-
+		memcpy(devname, buffer, *lenp);
 		devname[*lenp] = 0;
 		strip_it(devname);
 
@@ -238,9 +229,7 @@ static int dn_def_dev_handler(struct ctl_table *table, int write,
 
 	if (len > *lenp) len = *lenp;
 
-	if (copy_to_user(buffer, devname, len))
-		return -EFAULT;
-
+	memcpy(buffer, devname, len);
 	*lenp = len;
 	*ppos += len;
 
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 30fa42f5997d..a118978d222c 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -2361,8 +2361,7 @@ static int devinet_conf_ifindex(struct net *net, struct ipv4_devconf *cnf)
 }
 
 static int devinet_conf_proc(struct ctl_table *ctl, int write,
-			     void __user *buffer,
-			     size_t *lenp, loff_t *ppos)
+			     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int old_value = *(int *)ctl->data;
 	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
@@ -2414,8 +2413,7 @@ static int devinet_conf_proc(struct ctl_table *ctl, int write,
 }
 
 static int devinet_sysctl_forward(struct ctl_table *ctl, int write,
-				  void __user *buffer,
-				  size_t *lenp, loff_t *ppos)
+				  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int val = *valp;
@@ -2458,8 +2456,7 @@ static int devinet_sysctl_forward(struct ctl_table *ctl, int write,
 }
 
 static int ipv4_doint_and_flush(struct ctl_table *ctl, int write,
-				void __user *buffer,
-				size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int val = *valp;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 788c69d9bfe0..041f4dcac440 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -3336,8 +3336,7 @@ static int ip_rt_gc_elasticity __read_mostly	= 8;
 static int ip_min_valid_pmtu __read_mostly	= IPV4_MIN_MTU;
 
 static int ipv4_sysctl_rtcache_flush(struct ctl_table *__ctl, int write,
-					void __user *buffer,
-					size_t *lenp, loff_t *ppos)
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = (struct net *)__ctl->extra1;
 
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 81b267e990a1..868e317cc324 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -71,8 +71,7 @@ static void set_local_port_range(struct net *net, int range[2])
 
 /* Validate changes from /proc interface. */
 static int ipv4_local_port_range(struct ctl_table *table, int write,
-				 void __user *buffer,
-				 size_t *lenp, loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net =
 		container_of(table->data, struct net, ipv4.ip_local_ports.range);
@@ -107,7 +106,7 @@ static int ipv4_local_port_range(struct ctl_table *table, int write,
 
 /* Validate changes from /proc interface. */
 static int ipv4_privileged_ports(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = container_of(table->data, struct net,
 	    ipv4.sysctl_ip_prot_sock);
@@ -168,8 +167,7 @@ static void set_ping_group_range(struct ctl_table *table, kgid_t low, kgid_t hig
 
 /* Validate changes from /proc interface. */
 static int ipv4_ping_group_range(struct ctl_table *table, int write,
-				 void __user *buffer,
-				 size_t *lenp, loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct user_namespace *user_ns = current_user_ns();
 	int ret;
@@ -204,8 +202,7 @@ static int ipv4_ping_group_range(struct ctl_table *table, int write,
 }
 
 static int ipv4_fwd_update_priority(struct ctl_table *table, int write,
-				    void __user *buffer,
-				    size_t *lenp, loff_t *ppos)
+				    void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net;
 	int ret;
@@ -221,7 +218,7 @@ static int ipv4_fwd_update_priority(struct ctl_table *table, int write,
 }
 
 static int proc_tcp_congestion_control(struct ctl_table *ctl, int write,
-				       void __user *buffer, size_t *lenp, loff_t *ppos)
+				       void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = container_of(ctl->data, struct net,
 				       ipv4.tcp_congestion_control);
@@ -241,9 +238,8 @@ static int proc_tcp_congestion_control(struct ctl_table *ctl, int write,
 }
 
 static int proc_tcp_available_congestion_control(struct ctl_table *ctl,
-						 int write,
-						 void __user *buffer, size_t *lenp,
-						 loff_t *ppos)
+						 int write, void *buffer,
+						 size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, };
 	int ret;
@@ -258,9 +254,8 @@ static int proc_tcp_available_congestion_control(struct ctl_table *ctl,
 }
 
 static int proc_allowed_congestion_control(struct ctl_table *ctl,
-					   int write,
-					   void __user *buffer, size_t *lenp,
-					   loff_t *ppos)
+					   int write, void *buffer,
+					   size_t *lenp, loff_t *ppos)
 {
 	struct ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
 	int ret;
@@ -296,8 +291,7 @@ static int sscanf_key(char *buf, __le32 *key)
 }
 
 static int proc_tcp_fastopen_key(struct ctl_table *table, int write,
-				 void __user *buffer, size_t *lenp,
-				 loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = container_of(table->data, struct net,
 	    ipv4.sysctl_tcp_fastopen);
@@ -399,7 +393,7 @@ static void proc_configure_early_demux(int enabled, int protocol)
 }
 
 static int proc_tcp_early_demux(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret = 0;
 
@@ -415,7 +409,7 @@ static int proc_tcp_early_demux(struct ctl_table *table, int write,
 }
 
 static int proc_udp_early_demux(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret = 0;
 
@@ -431,8 +425,7 @@ static int proc_udp_early_demux(struct ctl_table *table, int write,
 }
 
 static int proc_tfo_blackhole_detect_timeout(struct ctl_table *table,
-					     int write,
-					     void __user *buffer,
+					     int write, void *buffer,
 					     size_t *lenp, loff_t *ppos)
 {
 	struct net *net = container_of(table->data, struct net,
@@ -447,8 +440,7 @@ static int proc_tfo_blackhole_detect_timeout(struct ctl_table *table,
 }
 
 static int proc_tcp_available_ulp(struct ctl_table *ctl,
-				  int write,
-				  void __user *buffer, size_t *lenp,
+				  int write, void *buffer, size_t *lenp,
 				  loff_t *ppos)
 {
 	struct ctl_table tbl = { .maxlen = TCP_ULP_BUF_MAX, };
@@ -466,7 +458,7 @@ static int proc_tcp_available_ulp(struct ctl_table *ctl,
 
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 static int proc_fib_multipath_hash_policy(struct ctl_table *table, int write,
-					  void __user *buffer, size_t *lenp,
+					  void *buffer, size_t *lenp,
 					  loff_t *ppos)
 {
 	struct net *net = container_of(table->data, struct net,
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 24e319dfb510..9d0e89bccb90 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -6108,9 +6108,8 @@ static void ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
 
 #ifdef CONFIG_SYSCTL
 
-static
-int addrconf_sysctl_forward(struct ctl_table *ctl, int write,
-			   void __user *buffer, size_t *lenp, loff_t *ppos)
+static int addrconf_sysctl_forward(struct ctl_table *ctl, int write,
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int val = *valp;
@@ -6134,9 +6133,8 @@ int addrconf_sysctl_forward(struct ctl_table *ctl, int write,
 	return ret;
 }
 
-static
-int addrconf_sysctl_mtu(struct ctl_table *ctl, int write,
-			void __user *buffer, size_t *lenp, loff_t *ppos)
+static int addrconf_sysctl_mtu(struct ctl_table *ctl, int write,
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct inet6_dev *idev = ctl->extra1;
 	int min_mtu = IPV6_MIN_MTU;
@@ -6206,9 +6204,8 @@ static int addrconf_disable_ipv6(struct ctl_table *table, int *p, int newf)
 	return 0;
 }
 
-static
-int addrconf_sysctl_disable(struct ctl_table *ctl, int write,
-			    void __user *buffer, size_t *lenp, loff_t *ppos)
+static int addrconf_sysctl_disable(struct ctl_table *ctl, int write,
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int val = *valp;
@@ -6232,9 +6229,8 @@ int addrconf_sysctl_disable(struct ctl_table *ctl, int write,
 	return ret;
 }
 
-static
-int addrconf_sysctl_proxy_ndp(struct ctl_table *ctl, int write,
-			      void __user *buffer, size_t *lenp, loff_t *ppos)
+static int addrconf_sysctl_proxy_ndp(struct ctl_table *ctl, int write,
+		void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int ret;
@@ -6275,7 +6271,7 @@ int addrconf_sysctl_proxy_ndp(struct ctl_table *ctl, int write,
 }
 
 static int addrconf_sysctl_addr_gen_mode(struct ctl_table *ctl, int write,
-					 void __user *buffer, size_t *lenp,
+					 void *buffer, size_t *lenp,
 					 loff_t *ppos)
 {
 	int ret = 0;
@@ -6337,7 +6333,7 @@ out:
 }
 
 static int addrconf_sysctl_stable_secret(struct ctl_table *ctl, int write,
-					 void __user *buffer, size_t *lenp,
+					 void *buffer, size_t *lenp,
 					 loff_t *ppos)
 {
 	int err;
@@ -6404,8 +6400,7 @@ out:
 
 static
 int addrconf_sysctl_ignore_routes_with_linkdown(struct ctl_table *ctl,
-						int write,
-						void __user *buffer,
+						int write, void *buffer,
 						size_t *lenp,
 						loff_t *ppos)
 {
@@ -6505,10 +6500,8 @@ int addrconf_disable_policy(struct ctl_table *ctl, int *valp, int val)
 	return 0;
 }
 
-static
-int addrconf_sysctl_disable_policy(struct ctl_table *ctl, int write,
-				   void __user *buffer, size_t *lenp,
-				   loff_t *ppos)
+static int addrconf_sysctl_disable_policy(struct ctl_table *ctl, int write,
+				   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = ctl->data;
 	int val = *valp;
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 1ecd4e9b0bdf..58f1255295d3 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1835,7 +1835,8 @@ static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl,
 	}
 }
 
-int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void __user *buffer, size_t *lenp, loff_t *ppos)
+int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, void *buffer,
+		size_t *lenp, loff_t *ppos)
 {
 	struct net_device *dev = ctl->extra1;
 	struct inet6_dev *idev;
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 310cbddaa533..acdb31e38412 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -6088,9 +6088,8 @@ static int rt6_stats_seq_show(struct seq_file *seq, void *v)
 
 #ifdef CONFIG_SYSCTL
 
-static
-int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
-			      void __user *buffer, size_t *lenp, loff_t *ppos)
+static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
+			      void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net;
 	int delay;
diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c
index 63b657aa8d29..fac2135aa47b 100644
--- a/net/ipv6/sysctl_net_ipv6.c
+++ b/net/ipv6/sysctl_net_ipv6.c
@@ -26,8 +26,7 @@ static int auto_flowlabels_min;
 static int auto_flowlabels_max = IP6_AUTO_FLOW_LABEL_MAX;
 
 static int proc_rt6_multipath_hash_policy(struct ctl_table *table, int write,
-					  void __user *buffer, size_t *lenp,
-					  loff_t *ppos)
+					  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net;
 	int ret;
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 4701edffb1f7..a42e4ed5ab0e 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -1362,8 +1362,7 @@ done:
 	(&((struct mpls_dev *)0)->field)
 
 static int mpls_conf_proc(struct ctl_table *ctl, int write,
-			  void __user *buffer,
-			  size_t *lenp, loff_t *ppos)
+			  void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int oval = *(int *)ctl->data;
 	int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
@@ -2594,7 +2593,7 @@ nolabels:
 }
 
 static int mpls_platform_labels(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = table->data;
 	int platform_labels = net->mpls.platform_labels;
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 8d14a1acbc37..412656c34f20 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -1736,7 +1736,7 @@ static int three = 3;
 
 static int
 proc_do_defense_mode(struct ctl_table *table, int write,
-		     void __user *buffer, size_t *lenp, loff_t *ppos)
+		     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct netns_ipvs *ipvs = table->extra2;
 	int *valp = table->data;
@@ -1763,7 +1763,7 @@ proc_do_defense_mode(struct ctl_table *table, int write,
 
 static int
 proc_do_sync_threshold(struct ctl_table *table, int write,
-		       void __user *buffer, size_t *lenp, loff_t *ppos)
+		       void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = table->data;
 	int val[2];
@@ -1788,7 +1788,7 @@ proc_do_sync_threshold(struct ctl_table *table, int write,
 
 static int
 proc_do_sync_ports(struct ctl_table *table, int write,
-		   void __user *buffer, size_t *lenp, loff_t *ppos)
+		   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int *valp = table->data;
 	int val = *valp;
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 9b57330c81f8..31b027b12ff3 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -517,7 +517,7 @@ static unsigned int nf_conntrack_htable_size_user __read_mostly;
 
 static int
 nf_conntrack_hash_sysctl(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+			 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 
diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index bb25d4c794c7..6cb9f9474b05 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -414,7 +414,7 @@ static struct ctl_table nf_log_sysctl_ftable[] = {
 };
 
 static int nf_log_proc_dostring(struct ctl_table *table, int write,
-			 void __user *buffer, size_t *lenp, loff_t *ppos)
+			 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	const struct nf_logger *logger;
 	char buf[NFLOGGER_NAME_LEN];
diff --git a/net/phonet/sysctl.c b/net/phonet/sysctl.c
index 251e750fd9aa..0d0bf41381c2 100644
--- a/net/phonet/sysctl.c
+++ b/net/phonet/sysctl.c
@@ -49,8 +49,7 @@ void phonet_get_local_port_range(int *min, int *max)
 }
 
 static int proc_local_port_range(struct ctl_table *table, int write,
-				void __user *buffer,
-				size_t *lenp, loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	int ret;
 	int range[2] = {local_port_range[0], local_port_range[1]};
diff --git a/net/rds/tcp.c b/net/rds/tcp.c
index 66121bc6f34e..46782fac4c16 100644
--- a/net/rds/tcp.c
+++ b/net/rds/tcp.c
@@ -62,8 +62,7 @@ static atomic_t rds_tcp_unloading = ATOMIC_INIT(0);
 static struct kmem_cache *rds_tcp_conn_slab;
 
 static int rds_tcp_skbuf_handler(struct ctl_table *ctl, int write,
-				 void __user *buffer, size_t *lenp,
-				 loff_t *fpos);
+				 void *buffer, size_t *lenp, loff_t *fpos);
 
 static int rds_tcp_min_sndbuf = SOCK_MIN_SNDBUF;
 static int rds_tcp_min_rcvbuf = SOCK_MIN_RCVBUF;
@@ -676,8 +675,7 @@ static void rds_tcp_sysctl_reset(struct net *net)
 }
 
 static int rds_tcp_skbuf_handler(struct ctl_table *ctl, int write,
-				 void __user *buffer, size_t *lenp,
-				 loff_t *fpos)
+				 void *buffer, size_t *lenp, loff_t *fpos)
 {
 	struct net *net = current->nsproxy->net_ns;
 	int err;
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
index 4740aa70e652..c16c80963e55 100644
--- a/net/sctp/sysctl.c
+++ b/net/sctp/sysctl.c
@@ -43,20 +43,15 @@ static unsigned long max_autoclose_max =
 	? UINT_MAX : MAX_SCHEDULE_TIMEOUT / HZ;
 
 static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos);
+				 void *buffer, size_t *lenp, loff_t *ppos);
 static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos);
-static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos);
+				void *buffer, size_t *lenp, loff_t *ppos);
+static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write, void *buffer,
+				size_t *lenp, loff_t *ppos);
 static int proc_sctp_do_alpha_beta(struct ctl_table *ctl, int write,
-				   void __user *buffer, size_t *lenp,
-				   loff_t *ppos);
+				   void *buffer, size_t *lenp, loff_t *ppos);
 static int proc_sctp_do_auth(struct ctl_table *ctl, int write,
-			     void __user *buffer, size_t *lenp,
-			     loff_t *ppos);
+			     void *buffer, size_t *lenp, loff_t *ppos);
 
 static struct ctl_table sctp_table[] = {
 	{
@@ -343,8 +338,7 @@ static struct ctl_table sctp_net_table[] = {
 };
 
 static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos)
+				 void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = current->nsproxy->net_ns;
 	struct ctl_table tbl;
@@ -389,8 +383,7 @@ static int proc_sctp_do_hmac_alg(struct ctl_table *ctl, int write,
 }
 
 static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = current->nsproxy->net_ns;
 	unsigned int min = *(unsigned int *) ctl->extra1;
@@ -418,8 +411,7 @@ static int proc_sctp_do_rto_min(struct ctl_table *ctl, int write,
 }
 
 static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
-				void __user *buffer, size_t *lenp,
-				loff_t *ppos)
+				void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = current->nsproxy->net_ns;
 	unsigned int min = *(unsigned int *) ctl->extra1;
@@ -447,8 +439,7 @@ static int proc_sctp_do_rto_max(struct ctl_table *ctl, int write,
 }
 
 static int proc_sctp_do_alpha_beta(struct ctl_table *ctl, int write,
-				   void __user *buffer, size_t *lenp,
-				   loff_t *ppos)
+				   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	if (write)
 		pr_warn_once("Changing rto_alpha or rto_beta may lead to "
@@ -458,8 +449,7 @@ static int proc_sctp_do_alpha_beta(struct ctl_table *ctl, int write,
 }
 
 static int proc_sctp_do_auth(struct ctl_table *ctl, int write,
-			     void __user *buffer, size_t *lenp,
-			     loff_t *ppos)
+			     void *buffer, size_t *lenp, loff_t *ppos)
 {
 	struct net *net = current->nsproxy->net_ns;
 	struct ctl_table tbl;
diff --git a/net/sunrpc/sysctl.c b/net/sunrpc/sysctl.c
index d75f17b56f0e..999eee1ed61c 100644
--- a/net/sunrpc/sysctl.c
+++ b/net/sunrpc/sysctl.c
@@ -60,7 +60,7 @@ rpc_unregister_sysctl(void)
 }
 
 static int proc_do_xprt(struct ctl_table *table, int write,
-			void __user *buffer, size_t *lenp, loff_t *ppos)
+			void *buffer, size_t *lenp, loff_t *ppos)
 {
 	char tmpbuf[256];
 	size_t len;
@@ -70,15 +70,15 @@ static int proc_do_xprt(struct ctl_table *table, int write,
 		return 0;
 	}
 	len = svc_print_xprts(tmpbuf, sizeof(tmpbuf));
-	return simple_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
+	return memory_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
 }
 
 static int
-proc_dodebug(struct ctl_table *table, int write,
-				void __user *buffer, size_t *lenp, loff_t *ppos)
+proc_dodebug(struct ctl_table *table, int write, void *buffer, size_t *lenp,
+	     loff_t *ppos)
 {
-	char		tmpbuf[20], c, *s = NULL;
-	char __user *p;
+	char		tmpbuf[20], *s = NULL;
+	char *p;
 	unsigned int	value;
 	size_t		left, len;
 
@@ -90,18 +90,17 @@ proc_dodebug(struct ctl_table *table, int write,
 	left = *lenp;
 
 	if (write) {
-		if (!access_ok(buffer, left))
-			return -EFAULT;
 		p = buffer;
-		while (left && __get_user(c, p) >= 0 && isspace(c))
-			left--, p++;
+		while (left && isspace(*p)) {
+			left--;
+			p++;
+		}
 		if (!left)
 			goto done;
 
 		if (left > sizeof(tmpbuf) - 1)
 			return -EINVAL;
-		if (copy_from_user(tmpbuf, p, left))
-			return -EFAULT;
+		memcpy(tmpbuf, p, left);
 		tmpbuf[left] = '\0';
 
 		value = simple_strtol(tmpbuf, &s, 0);
@@ -121,11 +120,9 @@ proc_dodebug(struct ctl_table *table, int write,
 		len = sprintf(tmpbuf, "0x%04x", *(unsigned int *) table->data);
 		if (len > left)
 			len = left;
-		if (copy_to_user(buffer, tmpbuf, len))
-			return -EFAULT;
+		memcpy(buffer, tmpbuf, len);
 		if ((left -= len) > 0) {
-			if (put_user('\n', (char __user *)buffer + len))
-				return -EFAULT;
+			*((char *)buffer + len) = '\n';
 			left--;
 		}
 	}
diff --git a/net/sunrpc/xprtrdma/svc_rdma.c b/net/sunrpc/xprtrdma/svc_rdma.c
index 97bca509a391..526da5d4710b 100644
--- a/net/sunrpc/xprtrdma/svc_rdma.c
+++ b/net/sunrpc/xprtrdma/svc_rdma.c
@@ -80,8 +80,7 @@ atomic_t rdma_stat_sq_prod;
  * current value.
  */
 static int read_reset_stat(struct ctl_table *table, int write,
-			   void __user *buffer, size_t *lenp,
-			   loff_t *ppos)
+			   void *buffer, size_t *lenp, loff_t *ppos)
 {
 	atomic_t *stat = (atomic_t *)table->data;
 
@@ -103,8 +102,8 @@ static int read_reset_stat(struct ctl_table *table, int write,
 		len -= *ppos;
 		if (len > *lenp)
 			len = *lenp;
-		if (len && copy_to_user(buffer, str_buf, len))
-			return -EFAULT;
+		if (len)
+			memcpy(buffer, str_buf, len);
 		*lenp = len;
 		*ppos += len;
 	}