diff options
-rw-r--r-- | net/netfilter/xt_owner.c | 41 |
1 files changed, 35 insertions, 6 deletions
diff --git a/net/netfilter/xt_owner.c b/net/netfilter/xt_owner.c index 1302b475abcb..a20e731b5b6c 100644 --- a/net/netfilter/xt_owner.c +++ b/net/netfilter/xt_owner.c @@ -21,11 +21,39 @@ static int owner_check(const struct xt_mtchk_param *par) { struct xt_owner_match_info *info = par->matchinfo; + struct net *net = par->net; - /* For now only allow adding matches from the initial user namespace */ + /* Only allow the common case where the userns of the writer + * matches the userns of the network namespace. + */ if ((info->match & (XT_OWNER_UID|XT_OWNER_GID)) && - (current_user_ns() != &init_user_ns)) + (current_user_ns() != net->user_ns)) return -EINVAL; + + /* Ensure the uids are valid */ + if (info->match & XT_OWNER_UID) { + kuid_t uid_min = make_kuid(net->user_ns, info->uid_min); + kuid_t uid_max = make_kuid(net->user_ns, info->uid_max); + + if (!uid_valid(uid_min) || !uid_valid(uid_max) || + (info->uid_max < info->uid_min) || + uid_lt(uid_max, uid_min)) { + return -EINVAL; + } + } + + /* Ensure the gids are valid */ + if (info->match & XT_OWNER_GID) { + kgid_t gid_min = make_kgid(net->user_ns, info->gid_min); + kgid_t gid_max = make_kgid(net->user_ns, info->gid_max); + + if (!gid_valid(gid_min) || !gid_valid(gid_max) || + (info->gid_max < info->gid_min) || + gid_lt(gid_max, gid_min)) { + return -EINVAL; + } + } + return 0; } @@ -35,6 +63,7 @@ owner_mt(const struct sk_buff *skb, struct xt_action_param *par) const struct xt_owner_match_info *info = par->matchinfo; const struct file *filp; struct sock *sk = skb_to_full_sk(skb); + struct net *net = par->net; if (sk == NULL || sk->sk_socket == NULL) return (info->match ^ info->invert) == 0; @@ -51,8 +80,8 @@ owner_mt(const struct sk_buff *skb, struct xt_action_param *par) (XT_OWNER_UID | XT_OWNER_GID)) == 0; if (info->match & XT_OWNER_UID) { - kuid_t uid_min = make_kuid(&init_user_ns, info->uid_min); - kuid_t uid_max = make_kuid(&init_user_ns, info->uid_max); + kuid_t uid_min = make_kuid(net->user_ns, info->uid_min); + kuid_t uid_max = make_kuid(net->user_ns, info->uid_max); if ((uid_gte(filp->f_cred->fsuid, uid_min) && uid_lte(filp->f_cred->fsuid, uid_max)) ^ !(info->invert & XT_OWNER_UID)) @@ -60,8 +89,8 @@ owner_mt(const struct sk_buff *skb, struct xt_action_param *par) } if (info->match & XT_OWNER_GID) { - kgid_t gid_min = make_kgid(&init_user_ns, info->gid_min); - kgid_t gid_max = make_kgid(&init_user_ns, info->gid_max); + kgid_t gid_min = make_kgid(net->user_ns, info->gid_min); + kgid_t gid_max = make_kgid(net->user_ns, info->gid_max); if ((gid_gte(filp->f_cred->fsgid, gid_min) && gid_lte(filp->f_cred->fsgid, gid_max)) ^ !(info->invert & XT_OWNER_GID)) |