f2fs crypto: check context consistent for rename2

For exchange rename, we should check context consistent of encryption
between new_dir and old_inode or old_dir and new_inode. Otherwise
inheritance of parent's encryption context will be broken.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: sync with ext4 approach]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 55d0d27dfdf2067b725070b14068849b21244323..1cc24a0cbc589b52a977ce6f53a7df3315aade43 100644 (file)
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -756,6 +756,14 @@ static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
        int old_nlink = 0, new_nlink = 0;
        int err = -ENOENT;
 
+       if ((f2fs_encrypted_inode(old_dir) || f2fs_encrypted_inode(new_dir)) &&
+               (old_dir != new_dir) &&
+               (!f2fs_is_child_context_consistent_with_parent(new_dir,
+                                                               old_inode) ||
+               !f2fs_is_child_context_consistent_with_parent(old_dir,
+                                                               new_inode)))
+               return -EPERM;
+
        f2fs_balance_fs(sbi);
 
        old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);