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

[Jaegeuk Kim]

Hi Chao,

On Mon, May 25, 2015 at 06:07:02PM +0800, Chao Yu wrote:
> 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@xxxxxxxxxxx>
> ---
>  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;
> +	}
> +

Seems like we need this?

---
 fs/f2fs/namei.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 55d0d27..4772c14 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -756,6 +756,21 @@ 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) {
+		if (f2fs_encrypted_inode(new_dir) &&
+			!f2fs_is_child_context_consistent_with_parent(new_dir,
+							old_inode)) {
+			err = -EPERM;
+			goto out;
+		}
+		if (f2fs_encrypted_inode(old_dir) &&
+			!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);
-- 
2.1.1

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