1 --- a/compat/backport-4.12.c
2 +++ b/compat/backport-4.12.c
3 @@ -225,6 +225,7 @@ int bp_extack_genl_register_family(struc
5 /* copy this since the family might access it directly */
6 family->attrbuf = copy->family.attrbuf;
7 + family->mcgrp_offset = copy->family.mcgrp_offset;
9 mutex_lock(&copies_mutex);
10 list_add_tail(©->list, &copies_list);