From 0625c883bc4b3eba6f93f268cf67b5664244c0fe Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 7 Feb 2012 16:48:55 -0800 Subject: [PATCH] userns: Convert tun/tap to use kuid and kgid where appropriate Cc: Maxim Krasnyansky Acked-by: David S. Miller Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman --- drivers/net/tun.c | 46 ++++++++++++++++++++++++++++++++-------------- init/Kconfig | 1 - 2 files changed, 32 insertions(+), 15 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 926d4db5cb38..a9bd9f384f5f 100644 --- a/drivers/net/tun.c +++ b/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: diff --git a/init/Kconfig b/init/Kconfig index eac23a6fa236..b445d6f49bcf 100644 --- a/init/Kconfig +++ b/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