[PATCH 1/3] f2fs crypto: check context consistent for rename2

[Chao Yu <chao2.yu@samsung.com>]

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>
---
 fs/f2fs/namei.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index daed09c..3188464 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -754,6 +754,15 @@ static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
 	int old_nlink = 0, new_nlink = 0;
 	int err = -ENOENT;
 
+	if ((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))) {
+		err = -EPERM;
+		goto out;
+	}
+
 	f2fs_balance_fs(sbi);
 
 	old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
-- 
2.3.0