diff --git a/include/uapi/linux/un.h b/include/uapi/linux/un.h index 3ed3e46c1b1f7ff4688a52edefbba051fba600bb..4f0ab3a548ad429963d803c802041b15a1332121 100644 --- a/include/uapi/linux/un.h +++ b/include/uapi/linux/un.h @@ -10,4 +10,6 @@ struct sockaddr_un { char sun_path[UNIX_PATH_MAX]; /* pathname */ }; +#define SIOCUNIXFILE (SIOCPROTOPRIVATE + 0) /* open a socket file with O_PATH */ + #endif /* _LINUX_UN_H */ diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index cef79873b09d2051663fedf37dc52874b7f7c415..e2d18b9f910fd10050faf9571e8532c10dba98da 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -117,6 +117,7 @@ #include #include #include +#include struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE]; EXPORT_SYMBOL_GPL(unix_socket_table); @@ -2592,6 +2593,43 @@ 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 +2648,9 @@ 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;