net/handshake: Unpin sock->file if a handshake is cancelled

If user space never calls DONE, sock->file's reference count remains
elevated. Enable sock->file to be freed eventually in this case.

Reported-by: Jakub Kacinski <kuba@kernel.org>
Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/handshake/handshake.h b/net/handshake/handshake.h
index 4dac965..8aeaadc 100644 (file)
--- a/net/handshake/handshake.h
+++ b/net/handshake/handshake.h
@@ -31,6 +31,7 @@ struct handshake_req {
        struct list_head                hr_list;
        struct rhash_head               hr_rhash;
        unsigned long                   hr_flags;
+       struct file                     *hr_file;
        const struct handshake_proto    *hr_proto;
        struct sock                     *hr_sk;
        void                            (*hr_odestruct)(struct sock *sk);

diff --git a/net/handshake/request.c b/net/handshake/request.c
index 94d5cef..d78d41a 100644 (file)
--- a/net/handshake/request.c
+++ b/net/handshake/request.c
@@ -239,6 +239,7 @@ int handshake_req_submit(struct socket *sock, struct handshake_req *req,
        }
        req->hr_odestruct = req->hr_sk->sk_destruct;
        req->hr_sk->sk_destruct = handshake_sk_destruct;
+       req->hr_file = sock->file;
 
        ret = -EOPNOTSUPP;
        net = sock_net(req->hr_sk);
@@ -334,6 +335,9 @@ bool handshake_req_cancel(struct sock *sk)
                return false;
        }
 
+       /* Request accepted and waiting for DONE */
+       fput(req->hr_file);
+
 out_true:
        trace_handshake_cancel(net, req, sk);