net/unix: don't show information about sockets from other namespaces

socket_diag shows information only about sockets from a namespace where
a diag socket lives.

But if we request information about one unix socket, the kernel don't
check that its netns is matched with a diag socket namespace, so any
user can get information about any unix socket in a system. This looks
like a bug.

v2: add a Fixes tag

Fixes: 51d7cccf0723 ("net: make sock diag per-namespace")
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/unix/diag.c b/net/unix/diag.c
index 4d9679701a6d..384c84e83462 100644
--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -257,6 +257,8 @@ static int unix_diag_get_exact(struct sk_buff *in_skb,
         err = -ENOENT;
         if (sk == NULL)
                 goto out_nosk;
+        if (!net_eq(sock_net(sk), net))
+                goto out;
 
         err = sock_diag_check_cookie(sk, req->udiag_cookie);
         if (err)