util/sss_ptr_hash: fixed double free in sss_ptr_hash_delete_cb()
Calling data->callback(value->ptr) in sss_ptr_hash_delete_cb() could lead
to freeing of value->ptr and thus to destruction of value->spy that is
attached to value->ptr.
In turn sss_ptr_hash_spy_destructor() calls sss_ptr_hash_delete() ->
hash_delete() -> sss_ptr_hash_delete_cb() again and in this recursive
execution hash entry was actually deleted and value was freed.
When stack was unwound back to "first" sss_ptr_hash_delete_cb() it tried
to free value again => double free.
To prevent this bug value and hence spy are now freed before execution of
Reviewed-by: Pavel Březina <email@example.com>