devinet_ioctl(): take copyin/copyout to caller

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

4 files changed, 35 insertions, 46 deletions

diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index 1ac5bf95bfdd..e16fe7d44a71 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -173,7 +173,7 @@ static inline struct net_device *ip_dev_find(struct net *net, __be32 addr)
 }
 
 int inet_addr_onlink(struct in_device *in_dev, __be32 a, __be32 b);
-int devinet_ioctl(struct net *net, unsigned int cmd, void __user *);
+int devinet_ioctl(struct net *net, unsigned int cmd, struct ifreq *);
 void devinet_init(void);
 struct in_device *inetdev_by_index(struct net *, int);
 __be32 inet_select_addr(const struct net_device *dev, __be32 dst, int scope);
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 54cccdd8b1e3..1c2bfee2e249 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -872,6 +872,8 @@ int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
         struct sock *sk = sock->sk;
         int err = 0;
         struct net *net = sock_net(sk);
+        void __user *p = (void __user *)arg;
+        struct ifreq ifr;
 
         switch (cmd) {
         case SIOCGSTAMP:
@@ -891,17 +893,26 @@ int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
                 err = arp_ioctl(net, cmd, (void __user *)arg);
                 break;
         case SIOCGIFADDR:
-        case SIOCSIFADDR:
         case SIOCGIFBRDADDR:
-        case SIOCSIFBRDADDR:
         case SIOCGIFNETMASK:
-        case SIOCSIFNETMASK:
         case SIOCGIFDSTADDR:
+        case SIOCGIFPFLAGS:
+                if (copy_from_user(&ifr, p, sizeof(struct ifreq)))
+                        return -EFAULT;
+                err = devinet_ioctl(net, cmd, &ifr);
+                if (!err && copy_to_user(p, &ifr, sizeof(struct ifreq)))
+                        err = -EFAULT;
+                break;
+
+        case SIOCSIFADDR:
+        case SIOCSIFBRDADDR:
+        case SIOCSIFNETMASK:
         case SIOCSIFDSTADDR:
         case SIOCSIFPFLAGS:
-        case SIOCGIFPFLAGS:
         case SIOCSIFFLAGS:
-                err = devinet_ioctl(net, cmd, (void __user *)arg);
+                if (copy_from_user(&ifr, p, sizeof(struct ifreq)))
+                        return -EFAULT;
+                err = devinet_ioctl(net, cmd, &ifr);
                 break;
         default:
                 if (sk->sk_prot->ioctl)
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 1771549d2438..e056c0067f2c 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -946,11 +946,10 @@ static int inet_abc_len(__be32 addr)
 }
 
 
-int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
+int devinet_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr)
 {
-        struct ifreq ifr;
         struct sockaddr_in sin_orig;
-        struct sockaddr_in *sin = (struct sockaddr_in *)&ifr.ifr_addr;
+        struct sockaddr_in *sin = (struct sockaddr_in *)&ifr->ifr_addr;
         struct in_device *in_dev;
         struct in_ifaddr **ifap = NULL;
         struct in_ifaddr *ifa = NULL;
@@ -959,22 +958,16 @@ int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
         int ret = -EFAULT;
         int tryaddrmatch = 0;
 
-        /*
-         *      Fetch the caller's info block into kernel space
-         */
-
-        if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
-                goto out;
-        ifr.ifr_name[IFNAMSIZ - 1] = 0;
+        ifr->ifr_name[IFNAMSIZ - 1] = 0;
 
         /* save original address for comparison */
         memcpy(&sin_orig, sin, sizeof(*sin));
 
-        colon = strchr(ifr.ifr_name, ':');
+        colon = strchr(ifr->ifr_name, ':');
         if (colon)
                 *colon = 0;
 
-        dev_load(net, ifr.ifr_name);
+        dev_load(net, ifr->ifr_name);
 
         switch (cmd) {
         case SIOCGIFADDR:       /* Get interface address */
@@ -1014,7 +1007,7 @@ int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
         rtnl_lock();
 
         ret = -ENODEV;
-        dev = __dev_get_by_name(net, ifr.ifr_name);
+        dev = __dev_get_by_name(net, ifr->ifr_name);
         if (!dev)
                 goto done;
 
@@ -1031,7 +1024,7 @@ int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
                            This is checked above. */
                         for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
                              ifap = &ifa->ifa_next) {
-                                if (!strcmp(ifr.ifr_name, ifa->ifa_label) &&
+                                if (!strcmp(ifr->ifr_name, ifa->ifa_label) &&
                                     sin_orig.sin_addr.s_addr ==
                                                         ifa->ifa_local) {
                                         break; /* found */
@@ -1044,7 +1037,7 @@ int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
                 if (!ifa) {
                         for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
                              ifap = &ifa->ifa_next)
-                                if (!strcmp(ifr.ifr_name, ifa->ifa_label))
+                                if (!strcmp(ifr->ifr_name, ifa->ifa_label))
                                         break;
                 }
         }
@@ -1056,19 +1049,19 @@ int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
         switch (cmd) {
         case SIOCGIFADDR:       /* Get interface address */
                 sin->sin_addr.s_addr = ifa->ifa_local;
-                goto rarok;
+                break;
 
         case SIOCGIFBRDADDR:    /* Get the broadcast address */
                 sin->sin_addr.s_addr = ifa->ifa_broadcast;
-                goto rarok;
+                break;
 
         case SIOCGIFDSTADDR:    /* Get the destination address */
                 sin->sin_addr.s_addr = ifa->ifa_address;
-                goto rarok;
+                break;
 
         case SIOCGIFNETMASK:    /* Get the netmask for the interface */
                 sin->sin_addr.s_addr = ifa->ifa_mask;
-                goto rarok;
+                break;
 
         case SIOCSIFFLAGS:
                 if (colon) {
@@ -1076,11 +1069,11 @@ int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
                         if (!ifa)
                                 break;
                         ret = 0;
-                        if (!(ifr.ifr_flags & IFF_UP))
+                        if (!(ifr->ifr_flags & IFF_UP))
                                 inet_del_ifa(in_dev, ifap, 1);
                         break;
                 }
-                ret = dev_change_flags(dev, ifr.ifr_flags);
+                ret = dev_change_flags(dev, ifr->ifr_flags);
                 break;
 
         case SIOCSIFADDR:       /* Set interface address (and family) */
@@ -1095,7 +1088,7 @@ int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
                                 break;
                         INIT_HLIST_NODE(&ifa->hash);
                         if (colon)
-                                memcpy(ifa->ifa_label, ifr.ifr_name, IFNAMSIZ);
+                                memcpy(ifa->ifa_label, ifr->ifr_name, IFNAMSIZ);
                         else
                                 memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
                 } else {
@@ -1182,10 +1175,6 @@ done:
         rtnl_unlock();
 out:
         return ret;
-rarok:
-        rtnl_unlock();
-        ret = copy_to_user(arg, &ifr, sizeof(struct ifreq)) ? -EFAULT : 0;
-        goto out;
 }
 
 static int inet_gifconf(struct net_device *dev, char __user *buf, int len, int size)
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index e9e488e72900..6895fff609b1 100644
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -329,17 +329,6 @@ set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
         sin->sin_port = port;
 }
 
-static int __init ic_devinet_ioctl(unsigned int cmd, struct ifreq *arg)
-{
-        int res;
-
-        mm_segment_t oldfs = get_fs();
-        set_fs(get_ds());
-        res = devinet_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
-        set_fs(oldfs);
-        return res;
-}
-
 static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
 {
         int res;
@@ -375,19 +364,19 @@ static int __init ic_setup_if(void)
         memset(&ir, 0, sizeof(ir));
         strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
         set_sockaddr(sin, ic_myaddr, 0);
-        if ((err = ic_devinet_ioctl(SIOCSIFADDR, &ir)) < 0) {
+        if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) {
                 pr_err("IP-Config: Unable to set interface address (%d)\n",
                        err);
                 return -1;
         }
         set_sockaddr(sin, ic_netmask, 0);
-        if ((err = ic_devinet_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
+        if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) {
                 pr_err("IP-Config: Unable to set interface netmask (%d)\n",
                        err);
                 return -1;
         }
         set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
-        if ((err = ic_devinet_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
+        if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) {
                 pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
                        err);
                 return -1;