tree 72e26cc11b0a252f8679253082d2ce19f3db3407
parent 33f9cff6ec2fbfcf0b40d4328d292c745185fdf4
author Miklos Szeredi <mszeredi@redhat.com> 1470224667 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1470822570 +0200

vfs: fix deadlock in file_remove_privs() on overlayfs

commit c1892c37769cf89c7e7ba57528ae2ccb5d153c9b upstream.

file_remove_privs() is called with inode lock on file_inode(), which
proceeds to calling notify_change() on file->f_path.dentry.  Which triggers
the WARN_ON_ONCE(!inode_is_locked(inode)) in addition to deadlocking later
when ovl_setattr tries to lock the underlying inode again.

Fix this mess by not mixing the layers, but doing everything on underlying
dentry/inode.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 07a2daab49c5 ("ovl: Copy up underlying inode's ->i_mode to overlay inode")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>