nsproxy: restore EINVAL for non-namespace file descriptor

The LTP testsuite reported a regression where users would now see EBADF
returned instead of EINVAL when an fd was passed that referred to an open
file but the file was not a nsfd. Fix this by continuing to report EINVAL.

Reported-by: kernel test robot <rong.a.chen@intel.com>
Cc: Jan Stancek <jstancek@redhat.com>
Cc: Cyril Hrubis <chrubis@suse.cz>
Link: https://lore.kernel.org/lkml/20200615085836.GR12456@shao2-debian
Fixes: 303cc571d107 ("nsproxy: attach to namespaces via pidfds")
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index b03df67..cd35663 100644 (file)
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -531,7 +531,7 @@ SYSCALL_DEFINE2(setns, int, fd, int, flags)
        } else if (!IS_ERR(pidfd_pid(file))) {
                err = check_setns_flags(flags);
        } else {
-               err = -EBADF;
+               err = -EINVAL;
        }
        if (err)
                goto out;