unexport sock_map_fd(), switch to sock_alloc_file()

Both modular callers of sock_map_fd() had been buggy; sctp one leaks
descriptor and file if copy_to_user() fails, 9p one shouldn't be
exposing file in the descriptor table at all.

Switch both to sock_alloc_file(), export it, unexport sock_map_fd() and
make it static.

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

1 files changed, 7 insertions, 9 deletions

diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index 6449bae15702..8c4e0b538a8a 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -793,30 +793,28 @@ static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
 static int p9_socket_open(struct p9_client *client, struct socket *csocket)
 {
 	struct p9_trans_fd *p;
-	int ret, fd;
+	struct file *file;
+	int ret;
 
 	p = kmalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
 	if (!p)
 		return -ENOMEM;
 
 	csocket->sk->sk_allocation = GFP_NOIO;
-	fd = sock_map_fd(csocket, 0);
-	if (fd < 0) {
+	file = sock_alloc_file(csocket, 0);
+	if (IS_ERR(file)) {
 		pr_err("%s (%d): failed to map fd\n",
 		       __func__, task_pid_nr(current));
 		sock_release(csocket);
 		kfree(p);
-		return fd;
+		return PTR_ERR(file);
 	}
 
-	get_file(csocket->file);
-	get_file(csocket->file);
-	p->wr = p->rd = csocket->file;
+	get_file(file);
+	p->wr = p->rd = file;
 	client->trans = p;
 	client->status = Connected;
 
-	sys_close(fd);	/* still racy */
-
 	p->rd->f_flags |= O_NONBLOCK;
 
 	p->conn = p9_conn_create(client);