Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

This is an initial merge in of Eric Biederman's work to start adding
user namespace support to the networking.

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 55 insertions, 18 deletions

diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index 169ab59..4142aac 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -55,6 +55,7 @@ struct nfulnl_instance {
 	unsigned int qlen;		/* number of nlmsgs in skb */
 	struct sk_buff *skb;		/* pre-allocatd skb */
 	struct timer_list timer;
+	struct user_namespace *peer_user_ns;	/* User namespace of the peer process */
 	int peer_pid;			/* PID of the peer process */
 
 	/* configurable parameters */
@@ -132,7 +133,7 @@ instance_put(struct nfulnl_instance *inst)
 static void nfulnl_timer(unsigned long data);
 
 static struct nfulnl_instance *
-instance_create(u_int16_t group_num, int pid)
+instance_create(u_int16_t group_num, int pid, struct user_namespace *user_ns)
 {
 	struct nfulnl_instance *inst;
 	int err;
@@ -162,6 +163,7 @@ instance_create(u_int16_t group_num, int pid)
 
 	setup_timer(&inst->timer, nfulnl_timer, (unsigned long)inst);
 
+	inst->peer_user_ns = user_ns;
 	inst->peer_pid = pid;
 	inst->group_num = group_num;
 
@@ -503,8 +505,11 @@ __build_packet_message(struct nfulnl_instance *inst,
 		read_lock_bh(&skb->sk->sk_callback_lock);
 		if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
 			struct file *file = skb->sk->sk_socket->file;
-			__be32 uid = htonl(file->f_cred->fsuid);
-			__be32 gid = htonl(file->f_cred->fsgid);
+			__be32 uid = htonl(from_kuid_munged(inst->peer_user_ns,
+							    file->f_cred->fsuid));
+			__be32 gid = htonl(from_kgid_munged(inst->peer_user_ns,
+							    file->f_cred->fsgid));
+			/* need to unlock here since NLA_PUT may goto */
 			read_unlock_bh(&skb->sk->sk_callback_lock);
 			if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
 			    nla_put_be32(inst->skb, NFULA_GID, gid))
@@ -783,7 +788,8 @@ nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 			}
 
 			inst = instance_create(group_num,
-					       NETLINK_CB(skb).pid);
+					       NETLINK_CB(skb).pid,
+					       sk_user_ns(NETLINK_CB(skb).ssk));
 			if (IS_ERR(inst)) {
 				ret = PTR_ERR(inst);
 				goto out;
diff --git a/net/netfilter/xt_LOG.c b/net/netfilter/xt_LOG.c
index ff5f75f..02a2bf4 100644
--- a/net/netfilter/xt_LOG.c
+++ b/net/netfilter/xt_LOG.c
@@ -363,10 +363,12 @@ static void dump_ipv4_packet(struct sbuff *m,
 	/* Max length: 15 "UID=4294967295 " */
 	if ((logflags & XT_LOG_UID) && !iphoff && skb->sk) {
 		read_lock_bh(&skb->sk->sk_callback_lock);
-		if (skb->sk->sk_socket && skb->sk->sk_socket->file)
+		if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
+			const struct cred *cred = skb->sk->sk_socket->file->f_cred;
 			sb_add(m, "UID=%u GID=%u ",
-				skb->sk->sk_socket->file->f_cred->fsuid,
-				skb->sk->sk_socket->file->f_cred->fsgid);
+				from_kuid_munged(&init_user_ns, cred->fsuid),
+				from_kgid_munged(&init_user_ns, cred->fsgid));
+		}
 		read_unlock_bh(&skb->sk->sk_callback_lock);
 	}
 
@@ -719,10 +721,12 @@ static void dump_ipv6_packet(struct sbuff *m,
 	/* Max length: 15 "UID=4294967295 " */
 	if ((logflags & XT_LOG_UID) && recurse && skb->sk) {
 		read_lock_bh(&skb->sk->sk_callback_lock);
-		if (skb->sk->sk_socket && skb->sk->sk_socket->file)
+		if (skb->sk->sk_socket && skb->sk->sk_socket->file) {
+			const struct cred *cred = skb->sk->sk_socket->file->f_cred;
 			sb_add(m, "UID=%u GID=%u ",
-				skb->sk->sk_socket->file->f_cred->fsuid,
-				skb->sk->sk_socket->file->f_cred->fsgid);
+				from_kuid_munged(&init_user_ns, cred->fsuid),
+				from_kgid_munged(&init_user_ns, cred->fsgid));
+		}
 		read_unlock_bh(&skb->sk->sk_callback_lock);
 	}
 
diff --git a/net/netfilter/xt_owner.c b/net/netfilter/xt_owner.c
index 772d738..ca2e577 100644
--- a/net/netfilter/xt_owner.c
+++ b/net/netfilter/xt_owner.c
@@ -17,6 +17,17 @@
 #include <linux/netfilter/x_tables.h>
 #include <linux/netfilter/xt_owner.h>
 
+static int owner_check(const struct xt_mtchk_param *par)
+{
+	struct xt_owner_match_info *info = par->matchinfo;
+
+	/* For now only allow adding matches from the initial user namespace */
+	if ((info->match & (XT_OWNER_UID|XT_OWNER_GID)) &&
+	    (current_user_ns() != &init_user_ns))
+		return -EINVAL;
+	return 0;
+}
+
 static bool
 owner_mt(const struct sk_buff *skb, struct xt_action_param *par)
 {
@@ -37,17 +48,23 @@ owner_mt(const struct sk_buff *skb, struct xt_action_param *par)
 		return ((info->match ^ info->invert) &
 		       (XT_OWNER_UID | XT_OWNER_GID)) == 0;
 
-	if (info->match & XT_OWNER_UID)
-		if ((filp->f_cred->fsuid >= info->uid_min &&
-		    filp->f_cred->fsuid <= info->uid_max) ^
+	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);
+		if ((uid_gte(filp->f_cred->fsuid, uid_min) &&
+		     uid_lte(filp->f_cred->fsuid, uid_max)) ^
 		    !(info->invert & XT_OWNER_UID))
 			return false;
+	}
 
-	if (info->match & XT_OWNER_GID)
-		if ((filp->f_cred->fsgid >= info->gid_min &&
-		    filp->f_cred->fsgid <= info->gid_max) ^
+	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);
+		if ((gid_gte(filp->f_cred->fsgid, gid_min) &&
+		     gid_lte(filp->f_cred->fsgid, gid_max)) ^
 		    !(info->invert & XT_OWNER_GID))
 			return false;
+	}
 
 	return true;
 }
@@ -56,6 +73,7 @@ static struct xt_match owner_mt_reg __read_mostly = {
 	.name       = "owner",
 	.revision   = 1,
 	.family     = NFPROTO_UNSPEC,
+	.checkentry = owner_check,
 	.match      = owner_mt,
 	.matchsize  = sizeof(struct xt_owner_match_info),
 	.hooks      = (1 << NF_INET_LOCAL_OUT) |
diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c
index ae2ad1e..4635c9b 100644
--- a/net/netfilter/xt_recent.c
+++ b/net/netfilter/xt_recent.c
@@ -317,6 +317,8 @@ static int recent_mt_check(const struct xt_mtchk_param *par,
 	struct recent_table *t;
 #ifdef CONFIG_PROC_FS
 	struct proc_dir_entry *pde;
+	kuid_t uid;
+	kgid_t gid;
 #endif
 	unsigned int i;
 	int ret = -EINVAL;
@@ -372,6 +374,13 @@ static int recent_mt_check(const struct xt_mtchk_param *par,
 	for (i = 0; i < ip_list_hash_size; i++)
 		INIT_LIST_HEAD(&t->iphash[i]);
 #ifdef CONFIG_PROC_FS
+	uid = make_kuid(&init_user_ns, ip_list_uid);
+	gid = make_kgid(&init_user_ns, ip_list_gid);
+	if (!uid_valid(uid) || !gid_valid(gid)) {
+		kfree(t);
+		ret = -EINVAL;
+		goto out;
+	}
 	pde = proc_create_data(t->name, ip_list_perms, recent_net->xt_recent,
 		  &recent_mt_fops, t);
 	if (pde == NULL) {
@@ -379,8 +388,8 @@ static int recent_mt_check(const struct xt_mtchk_param *par,
 		ret = -ENOMEM;
 		goto out;
 	}
-	pde->uid = ip_list_uid;
-	pde->gid = ip_list_gid;
+	pde->uid = uid;
+	pde->gid = gid;
 #endif
 	spin_lock_bh(&recent_lock);
 	list_add_tail(&t->list, &recent_net->tables);