1 files changed, 45 insertions, 3 deletions

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index cef79873b09d..928691c43408 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -85,7 +85,7 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/signal.h>
-#include <linux/sched.h>
+#include <linux/sched/signal.h>
 #include <linux/errno.h>
 #include <linux/string.h>
 #include <linux/stat.h>
@@ -117,6 +117,7 @@
 #include <net/checksum.h>
 #include <linux/security.h>
 #include <linux/freezer.h>
+#include <linux/file.h>
 
 struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE];
 EXPORT_SYMBOL_GPL(unix_socket_table);
@@ -635,7 +636,7 @@ static int unix_bind(struct socket *, struct sockaddr *, int);
 static int unix_stream_connect(struct socket *, struct sockaddr *,
 			       int addr_len, int flags);
 static int unix_socketpair(struct socket *, struct socket *);
-static int unix_accept(struct socket *, struct socket *, int);
+static int unix_accept(struct socket *, struct socket *, int, bool);
 static int unix_getname(struct socket *, struct sockaddr *, int *, int);
 static unsigned int unix_poll(struct file *, struct socket *, poll_table *);
 static unsigned int unix_dgram_poll(struct file *, struct socket *,
@@ -1401,7 +1402,8 @@ static void unix_sock_inherit_flags(const struct socket *old,
 		set_bit(SOCK_PASSSEC, &new->flags);
 }
 
-static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
+static int unix_accept(struct socket *sock, struct socket *newsock, int flags,
+		       bool kern)
 {
 	struct sock *sk = sock->sk;
 	struct sock *tsk;
@@ -2592,6 +2594,43 @@ long unix_outq_len(struct sock *sk)
 }
 EXPORT_SYMBOL_GPL(unix_outq_len);
 
+static int unix_open_file(struct sock *sk)
+{
+	struct path path;
+	struct file *f;
+	int fd;
+
+	if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
+		return -EPERM;
+
+	unix_state_lock(sk);
+	path = unix_sk(sk)->path;
+	if (!path.dentry) {
+		unix_state_unlock(sk);
+		return -ENOENT;
+	}
+
+	path_get(&path);
+	unix_state_unlock(sk);
+
+	fd = get_unused_fd_flags(O_CLOEXEC);
+	if (fd < 0)
+		goto out;
+
+	f = dentry_open(&path, O_PATH, current_cred());
+	if (IS_ERR(f)) {
+		put_unused_fd(fd);
+		fd = PTR_ERR(f);
+		goto out;
+	}
+
+	fd_install(fd, f);
+out:
+	path_put(&path);
+
+	return fd;
+}
+
 static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 {
 	struct sock *sk = sock->sk;
@@ -2610,6 +2649,9 @@ static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 		else
 			err = put_user(amount, (int __user *)arg);
 		break;
+	case SIOCUNIXFILE:
+		err = unix_open_file(sk);
+		break;
 	default:
 		err = -ENOIOCTLCMD;
 		break;