[PATCH 4.9 17/39] net/unix: dont show information about sockets from other namespaces

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andrei Vagin <avagin@xxxxxxxxxx>


[ Upstream commit 0f5da659d8f1810f44de14acf2c80cd6499623a0 ]

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@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/unix/diag.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -257,6 +257,8 @@ static int unix_diag_get_exact(struct sk
 	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)