net: Allow userns root control of the core of the network stack.
Allow an unpriviled user who has created a user namespace, and then
created a network namespace to effectively use the new network
namespace, by reducing capable(CAP_NET_ADMIN) and
capable(CAP_NET_RAW) calls to be ns_capable(net->user_ns,
CAP_NET_ADMIN), or capable(net->user_ns, CAP_NET_RAW) calls.
Settings that merely control a single network device are allowed.
Either the network device is a logical network device where
restrictions make no difference or the network device is hardware NIC
that has been explicity moved from the initial network namespace.
In general policy and network stack state changes are allowed
while resource control is left unchanged.
Allow ethtool ioctls.
Allow binding to network devices.
Allow setting the socket mark.
Allow setting the socket priority.
Allow setting the network device alias via sysfs.
Allow setting the mtu via sysfs.
Allow changing the network device flags via sysfs.
Allow setting the network device group via sysfs.
Allow the following network device ioctls.
SIOCGMIIPHY
SIOCGMIIREG
SIOCSIFNAME
SIOCSIFFLAGS
SIOCSIFMETRIC
SIOCSIFMTU
SIOCSIFHWADDR
SIOCSIFSLAVE
SIOCADDMULTI
SIOCDELMULTI
SIOCSIFHWBROADCAST
SIOCSMIIREG
SIOCBONDENSLAVE
SIOCBONDRELEASE
SIOCBONDSETHWADDR
SIOCBONDCHANGEACTIVE
SIOCBRADDIF
SIOCBRDELIF
SIOCSHWTSTAMP
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 974199d..0afae8b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5279,7 +5279,7 @@
case SIOCGMIIPHY:
case SIOCGMIIREG:
case SIOCSIFNAME:
- if (!capable(CAP_NET_ADMIN))
+ if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
dev_load(net, ifr.ifr_name);
rtnl_lock();
@@ -5300,16 +5300,25 @@
* - require strict serialization.
* - do not return a value
*/
+ case SIOCSIFMAP:
+ case SIOCSIFTXQLEN:
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+ /* fall through */
+ /*
+ * These ioctl calls:
+ * - require local superuser power.
+ * - require strict serialization.
+ * - do not return a value
+ */
case SIOCSIFFLAGS:
case SIOCSIFMETRIC:
case SIOCSIFMTU:
- case SIOCSIFMAP:
case SIOCSIFHWADDR:
case SIOCSIFSLAVE:
case SIOCADDMULTI:
case SIOCDELMULTI:
case SIOCSIFHWBROADCAST:
- case SIOCSIFTXQLEN:
case SIOCSMIIREG:
case SIOCBONDENSLAVE:
case SIOCBONDRELEASE:
@@ -5318,7 +5327,7 @@
case SIOCBRADDIF:
case SIOCBRDELIF:
case SIOCSHWTSTAMP:
- if (!capable(CAP_NET_ADMIN))
+ if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
/* fall through */
case SIOCBONDSLAVEINFOQUERY:
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 4d64cc2..a870543 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -1460,7 +1460,7 @@
case ETHTOOL_GEEE:
break;
default:
- if (!capable(CAP_NET_ADMIN))
+ if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
}
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index bcf02f6..c66b8c2 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -73,11 +73,12 @@
const char *buf, size_t len,
int (*set)(struct net_device *, unsigned long))
{
- struct net_device *net = to_net_dev(dev);
+ struct net_device *netdev = to_net_dev(dev);
+ struct net *net = dev_net(netdev);
unsigned long new;
int ret = -EINVAL;
- if (!capable(CAP_NET_ADMIN))
+ if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
ret = kstrtoul(buf, 0, &new);
@@ -87,8 +88,8 @@
if (!rtnl_trylock())
return restart_syscall();
- if (dev_isalive(net)) {
- if ((ret = (*set)(net, new)) == 0)
+ if (dev_isalive(netdev)) {
+ if ((ret = (*set)(netdev, new)) == 0)
ret = len;
}
rtnl_unlock();
@@ -264,6 +265,9 @@
struct device_attribute *attr,
const char *buf, size_t len)
{
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+
return netdev_store(dev, attr, buf, len, change_tx_queue_len);
}
@@ -271,10 +275,11 @@
const char *buf, size_t len)
{
struct net_device *netdev = to_net_dev(dev);
+ struct net *net = dev_net(netdev);
size_t count = len;
ssize_t ret;
- if (!capable(CAP_NET_ADMIN))
+ if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
/* ignore trailing newline */
diff --git a/net/core/sock.c b/net/core/sock.c
index 0628600..d4f7b58 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -515,7 +515,7 @@
/* Sorry... */
ret = -EPERM;
- if (!capable(CAP_NET_RAW))
+ if (!ns_capable(net->user_ns, CAP_NET_RAW))
goto out;
ret = -EINVAL;
@@ -696,7 +696,8 @@
break;
case SO_PRIORITY:
- if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN))
+ if ((val >= 0 && val <= 6) ||
+ ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
sk->sk_priority = val;
else
ret = -EPERM;
@@ -813,7 +814,7 @@
clear_bit(SOCK_PASSSEC, &sock->flags);
break;
case SO_MARK:
- if (!capable(CAP_NET_ADMIN))
+ if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
ret = -EPERM;
else
sk->sk_mark = val;