From ab81dabda1d4edc1728173be6c6a279455f220e3 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 16 Mar 2019 09:45:42 -0400
Subject: fix sysfs_init_fs_context() in !CONFIG_NET_NS case

Permission checks on current's netns should be done only when
netns are enabled.

Reported-by: Dominik Brodowski <linux@dominikbrodowski.net>
Fixes: 23bf1b6be9c2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/sysfs/mount.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

(limited to 'fs')

diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index 4cb21b558a85..1b56686ab178 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -71,9 +71,11 @@ static int sysfs_init_fs_context(struct fs_context *fc)
 	kfc->magic = SYSFS_MAGIC;
 	fc->fs_private = kfc;
 	fc->ops = &sysfs_fs_context_ops;
-	if (fc->user_ns)
-		put_user_ns(fc->user_ns);
-	fc->user_ns = get_user_ns(netns->user_ns);
+	if (netns) {
+		if (fc->user_ns)
+			put_user_ns(fc->user_ns);
+		fc->user_ns = get_user_ns(netns->user_ns);
+	}
 	fc->global = true;
 	return 0;
 }
-- 
cgit