tree 7f36d4f2a49719673c436767707d25ef5f5e9041
parent 07a2daab49c549a37b5b744cbebb6e3f445f12bc
author Maxim Patlasov <mpatlasov@virtuozzo.com> 1469150666 -0700
committer Miklos Szeredi <mszeredi@redhat.com> 1469177660 +0200

ovl: verify upper dentry in ovl_remove_and_whiteout()

The upper dentry may become stale before we call ovl_lock_rename_workdir.
For example, someone could (mistakenly or maliciously) manually unlink(2)
it directly from upperdir.

To ensure it is not stale, let's lookup it after ovl_lock_rename_workdir
and and check if it matches the upper dentry.

Essentially, it is the same problem and similar solution as in
commit 11f3710417d0 ("ovl: verify upper dentry before unlink and rename").

Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org>