ovl: verify upper dentry in ovl_remove_and_whiteout()

Browse source

commit cfc9fde0b0 upstream.

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 11f3710417 ("ovl: verify upper dentry before unlink and rename").

Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Maxim Patlasov 2016-07-21 18:24:26 -07:00 • committed by Greg Kroah-Hartman

parent c12dada5f2

commit cf2a2c6de0

1 changed files with 24 additions and 30 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

54

fs/overlayfs/dir.c

View file