[PATCH 02/10] devinet_ioctl(): take copyin/copyout to caller

From: Al Viro
Date: Thu Jan 18 2018 - 14:38:47 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
include/linux/inetdevice.h | 2 +-
net/ipv4/af_inet.c | 21 ++++++++++++++++-----
net/ipv4/devinet.c | 41 +++++++++++++++--------------------------
net/ipv4/ipconfig.c | 17 +++--------------
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 @@ int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
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;
--
2.11.0