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userns: Convert tun/tap to use kuid and kgid where appropriate

Cc: Maxim Krasnyansky <maxk@qualcomm.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
master
Eric W. Biederman 10 years ago
parent
commit
0625c883bc
  1. 46
      drivers/net/tun.c
  2. 1
      init/Kconfig

46
drivers/net/tun.c

@ -120,8 +120,8 @@ struct tun_sock;
struct tun_struct {
struct tun_file *tfile;
unsigned int flags;
uid_t owner;
gid_t group;
kuid_t owner;
kgid_t group;
struct net_device *dev;
netdev_features_t set_features;
@ -1032,8 +1032,8 @@ static void tun_setup(struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
tun->owner = -1;
tun->group = -1;
tun->owner = INVALID_UID;
tun->group = INVALID_GID;
dev->ethtool_ops = &tun_ethtool_ops;
dev->destructor = tun_free_netdev;
@ -1156,14 +1156,20 @@ static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct tun_struct *tun = netdev_priv(to_net_dev(dev));
return sprintf(buf, "%d\n", tun->owner);
return uid_valid(tun->owner)?
sprintf(buf, "%u\n",
from_kuid_munged(current_user_ns(), tun->owner)):
sprintf(buf, "-1\n");
}
static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct tun_struct *tun = netdev_priv(to_net_dev(dev));
return sprintf(buf, "%d\n", tun->group);
return gid_valid(tun->group) ?
sprintf(buf, "%u\n",
from_kgid_munged(current_user_ns(), tun->group)):
sprintf(buf, "-1\n");
}
static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
@ -1190,8 +1196,8 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
else
return -EINVAL;
if (((tun->owner != -1 && cred->euid != tun->owner) ||
(tun->group != -1 && !in_egroup_p(tun->group))) &&
if (((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
(gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
!capable(CAP_NET_ADMIN))
return -EPERM;
err = security_tun_dev_attach(tun->socket.sk);
@ -1375,6 +1381,8 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
void __user* argp = (void __user*)arg;
struct sock_fprog fprog;
struct ifreq ifr;
kuid_t owner;
kgid_t group;
int sndbuf;
int vnet_hdr_sz;
int ret;
@ -1448,16 +1456,26 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
case TUNSETOWNER:
/* Set owner of the device */
tun->owner = (uid_t) arg;
tun_debug(KERN_INFO, tun, "owner set to %d\n", tun->owner);
owner = make_kuid(current_user_ns(), arg);
if (!uid_valid(owner)) {
ret = -EINVAL;
break;
}
tun->owner = owner;
tun_debug(KERN_INFO, tun, "owner set to %d\n",
from_kuid(&init_user_ns, tun->owner));
break;
case TUNSETGROUP:
/* Set group of the device */
tun->group= (gid_t) arg;
tun_debug(KERN_INFO, tun, "group set to %d\n", tun->group);
group = make_kgid(current_user_ns(), arg);
if (!gid_valid(group)) {
ret = -EINVAL;
break;
}
tun->group = group;
tun_debug(KERN_INFO, tun, "group set to %d\n",
from_kgid(&init_user_ns, tun->group));
break;
case TUNSETLINK:

1
init/Kconfig

@ -1003,7 +1003,6 @@ config UIDGID_CONVERTED
depends on !UML || HOSTFS = n
# The rare drivers that won't build
depends on TUN = n
depends on INFINIBAND_QIB = n
depends on BLK_DEV_LOOP = n
depends on ANDROID_BINDER_IPC = n

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