Re: [PATCH v3] ceph: fix slab-use-after-free in have_mon_and_osd_map()

[David Howells <dhowells@xxxxxxxxxx>]

Viacheslav Dubeyko <slava@xxxxxxxxxxx> wrote:

> +	mutex_lock(&monc->mutex);
>  	kfree(monc->monmap);
> +	monc->monmap = NULL;
> +	mutex_unlock(&monc->mutex);

I would do the kfree after the locked region:

	mutex_lock(&monc->mutex);
	old_monmap = monc->monmap;
	monc->monmap = NULL;
	mutex_unlock(&monc->mutex);
	kfree(old_monmap);

David