enforce-policy-checks-on-cross-rename

   1 ext4 crypto: enforce crypto policy restrictions on cross-renames
   2
   3 Thanks to Chao Yu <chao2.yu@samsung.com> for pointing out the need for
   4 this check.
   5
   6 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
   7 ---
   8  fs/ext4/namei.c | 9 +++++++++
   9  1 file changed, 9 insertions(+)
  10
  11 diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
  12 index 8888977..24fc7a5 100644
  13 --- a/fs/ext4/namei.c
  14 +++ b/fs/ext4/namei.c
  15 @@ -3653,6 +3653,15 @@ static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
  16         u8 new_file_type;
  17         int retval;
  18
  19 +       if ((ext4_encrypted_inode(old_dir) ||
  20 +            ext4_encrypted_inode(new_dir)) &&
  21 +           (old_dir != new_dir) &&
  22 +           (!ext4_is_child_context_consistent_with_parent(new_dir,
  23 +                                                          old.inode) ||
  24 +            !ext4_is_child_context_consistent_with_parent(old_dir,
  25 +                                                          new.inode)))
  26 +               return -EPERM;
  27 +
  28         dquot_initialize(old.dir);
  29         dquot_initialize(new.dir);
  30