ubifs: Enforce crypto policy in ->link and ->rename

When a file is moved or linked into another directory
its current crypto policy has to be compatible with the
target policy.

Signed-off-by: Richard Weinberger <richard@nod.at>

diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index 4778175679712ef3d2fa9f93ee3889d0e82718b4..bd0af4e9ca0b1dafa2469da1d56d0a494858d22b 100644 (file)
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -639,6 +639,10 @@ static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
        ubifs_assert(inode_is_locked(dir));
        ubifs_assert(inode_is_locked(inode));
 
+       if (ubifs_crypt_is_encrypted(dir) &&
+           !fscrypt_has_permitted_context(dir, inode))
+               return -EPERM;
+
        err = dbg_check_synced_i_size(c, inode);
        if (err)
                return err;
@@ -1133,6 +1137,12 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
        if (unlink)
                ubifs_assert(inode_is_locked(new_inode));
 
+       if (old_dir != new_dir) {
+               if (ubifs_crypt_is_encrypted(new_dir) &&
+                   !fscrypt_has_permitted_context(new_dir, old_inode))
+                       return -EPERM;
+       }
+
        if (unlink && is_dir) {
                err = ubifs_check_dir_empty(new_inode);
                if (err)
@@ -1327,6 +1337,13 @@ static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
 
        ubifs_assert(fst_inode && snd_inode);
 
+       if ((ubifs_crypt_is_encrypted(old_dir) ||
+           ubifs_crypt_is_encrypted(new_dir)) &&
+           (old_dir != new_dir) &&
+           (!fscrypt_has_permitted_context(new_dir, fst_inode) ||
+            !fscrypt_has_permitted_context(old_dir, snd_inode)))
+               return -EPERM;
+
        lock_4_inodes(old_dir, new_dir, NULL, NULL);
 
        time = ubifs_current_time(old_dir);