Bluetooth: cmtp: cmtp_add_connection() should verify that it's dealing with l2cap socket

... rather than relying on ciptool(8) never passing it anything else.  Give
it e.g. an AF_UNIX connected socket (from socketpair(2)) and it'll oops,
trying to evaluate &l2cap_pi(sock->sk)->chan->dst...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/bluetooth/cmtp/core.c b/net/bluetooth/cmtp/core.c
index 67fe5e84e68f..278a194e6af4 100644
--- a/net/bluetooth/cmtp/core.c
+++ b/net/bluetooth/cmtp/core.c
@@ -334,6 +334,9 @@ int cmtp_add_connection(struct cmtp_connadd_req *req, struct socket *sock)
 
         BT_DBG("");
 
+        if (!l2cap_is_socket(sock))
+                return -EBADFD;
+
         session = kzalloc(sizeof(struct cmtp_session), GFP_KERNEL);
         if (!session)
                 return -ENOMEM;