userns: Teach inet_diag to work with user namespaces

Compute the user namespace of the socket that we are replying to
and translate the kuids of reported sockets into that user namespace.

Cc: Andrew Vagin <avagin@openvz.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

4 files changed, 20 insertions, 8 deletions

diff --git a/include/linux/inet_diag.h b/include/linux/inet_diag.h
index f1362b5447fc..e788c186ed3a 100644
--- a/include/linux/inet_diag.h
+++ b/include/linux/inet_diag.h
@@ -159,6 +159,7 @@ struct inet_diag_handler {
 struct inet_connection_sock;
 int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
                               struct sk_buff *skb, struct inet_diag_req_v2 *req,
+                              struct user_namespace *user_ns,
                               u32 pid, u32 seq, u16 nlmsg_flags,
                               const struct nlmsghdr *unlh);
 void inet_diag_dump_icsk(struct inet_hashinfo *h, struct sk_buff *skb,
diff --git a/init/Kconfig b/init/Kconfig
index 8447e0ca4186..07435e0c3a4b 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -950,7 +950,6 @@ config UIDGID_CONVERTED
         depends on NETFILTER_NETLINK_LOG = n
         depends on AF_RXRPC = n
         depends on NET_KEY = n
-        depends on INET_DIAG = n
         depends on DNS_RESOLVER = n
 
         # Filesystems
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 570e61f9611f..8bc005b1435f 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -69,6 +69,7 @@ static inline void inet_diag_unlock_handler(
 
 int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
                               struct sk_buff *skb, struct inet_diag_req_v2 *req,
+                              struct user_namespace *user_ns,                   
                               u32 pid, u32 seq, u16 nlmsg_flags,
                               const struct nlmsghdr *unlh)
 {
@@ -124,7 +125,7 @@ int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
         }
 #endif
 
-        r->idiag_uid = sock_i_uid(sk);
+        r->idiag_uid = from_kuid_munged(user_ns, sock_i_uid(sk));
         r->idiag_inode = sock_i_ino(sk);
 
         if (ext & (1 << (INET_DIAG_MEMINFO - 1))) {
@@ -199,11 +200,12 @@ EXPORT_SYMBOL_GPL(inet_sk_diag_fill);
 
 static int inet_csk_diag_fill(struct sock *sk,
                               struct sk_buff *skb, struct inet_diag_req_v2 *req,
+                              struct user_namespace *user_ns,
                               u32 pid, u32 seq, u16 nlmsg_flags,
                               const struct nlmsghdr *unlh)
 {
         return inet_sk_diag_fill(sk, inet_csk(sk),
-                        skb, req, pid, seq, nlmsg_flags, unlh);
+                        skb, req, user_ns, pid, seq, nlmsg_flags, unlh);
 }
 
 static int inet_twsk_diag_fill(struct inet_timewait_sock *tw,
@@ -256,14 +258,16 @@ static int inet_twsk_diag_fill(struct inet_timewait_sock *tw,
 }
 
 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
-                        struct inet_diag_req_v2 *r, u32 pid, u32 seq, u16 nlmsg_flags,
+                        struct inet_diag_req_v2 *r,
+                        struct user_namespace *user_ns,
+                        u32 pid, u32 seq, u16 nlmsg_flags,
                         const struct nlmsghdr *unlh)
 {
         if (sk->sk_state == TCP_TIME_WAIT)
                 return inet_twsk_diag_fill((struct inet_timewait_sock *)sk,
                                            skb, r, pid, seq, nlmsg_flags,
                                            unlh);
-        return inet_csk_diag_fill(sk, skb, r, pid, seq, nlmsg_flags, unlh);
+        return inet_csk_diag_fill(sk, skb, r, user_ns, pid, seq, nlmsg_flags, unlh);
 }
 
 int inet_diag_dump_one_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *in_skb,
@@ -311,6 +315,7 @@ int inet_diag_dump_one_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *in_s
         }
 
         err = sk_diag_fill(sk, rep, req,
+                           sk_user_ns(NETLINK_CB(in_skb).ssk),
                            NETLINK_CB(in_skb).pid,
                            nlh->nlmsg_seq, 0, nlh);
         if (err < 0) {
@@ -551,6 +556,7 @@ static int inet_csk_diag_dump(struct sock *sk,
                 return 0;
 
         return inet_csk_diag_fill(sk, skb, r,
+                                  sk_user_ns(NETLINK_CB(cb->skb).ssk),
                                   NETLINK_CB(cb->skb).pid,
                                   cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
 }
@@ -591,7 +597,9 @@ static int inet_twsk_diag_dump(struct inet_timewait_sock *tw,
 }
 
 static int inet_diag_fill_req(struct sk_buff *skb, struct sock *sk,
-                              struct request_sock *req, u32 pid, u32 seq,
+                              struct request_sock *req,
+                              struct user_namespace *user_ns,
+                              u32 pid, u32 seq,
                               const struct nlmsghdr *unlh)
 {
         const struct inet_request_sock *ireq = inet_rsk(req);
@@ -625,7 +633,7 @@ static int inet_diag_fill_req(struct sk_buff *skb, struct sock *sk,
         r->idiag_expires = jiffies_to_msecs(tmo);
         r->idiag_rqueue = 0;
         r->idiag_wqueue = 0;
-        r->idiag_uid = sock_i_uid(sk);
+        r->idiag_uid = from_kuid_munged(user_ns, sock_i_uid(sk));
         r->idiag_inode = 0;
 #if IS_ENABLED(CONFIG_IPV6)
         if (r->idiag_family == AF_INET6) {
@@ -702,6 +710,7 @@ static int inet_diag_dump_reqs(struct sk_buff *skb, struct sock *sk,
                         }
 
                         err = inet_diag_fill_req(skb, sk, req,
+                                               sk_user_ns(NETLINK_CB(cb->skb).ssk),
                                                NETLINK_CB(cb->skb).pid,
                                                cb->nlh->nlmsg_seq, cb->nlh);
                         if (err < 0) {
diff --git a/net/ipv4/udp_diag.c b/net/ipv4/udp_diag.c
index 16d0960062be..d2f336ea82ca 100644
--- a/net/ipv4/udp_diag.c
+++ b/net/ipv4/udp_diag.c
@@ -24,7 +24,9 @@ static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
         if (!inet_diag_bc_sk(bc, sk))
                 return 0;
 
-        return inet_sk_diag_fill(sk, NULL, skb, req, NETLINK_CB(cb->skb).pid,
+        return inet_sk_diag_fill(sk, NULL, skb, req,
+                        sk_user_ns(NETLINK_CB(cb->skb).ssk),
+                        NETLINK_CB(cb->skb).pid,
                         cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
 }
 
@@ -69,6 +71,7 @@ static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
                 goto out;
 
         err = inet_sk_diag_fill(sk, NULL, rep, req,
+                           sk_user_ns(NETLINK_CB(in_skb).ssk),
                            NETLINK_CB(in_skb).pid,
                            nlh->nlmsg_seq, 0, nlh);
         if (err < 0) {