a23f89a999
nf_ct_gre_keymap_flush() is useless. It is called from nf_conntrack_cleanup_net_list() only and tries to remove nf_ct_gre_keymap entries from pernet gre keymap list. Though: a) at this point the list should already be empty, all its entries were deleted during the conntracks cleanup, because nf_conntrack_cleanup_net_list() executes nf_ct_iterate_cleanup(kill_all) before nf_conntrack_proto_pernet_fini(): nf_conntrack_cleanup_net_list +- nf_ct_iterate_cleanup | nf_ct_put | nf_conntrack_put | nf_conntrack_destroy | destroy_conntrack | destroy_gre_conntrack | nf_ct_gre_keymap_destroy `- nf_conntrack_proto_pernet_fini nf_ct_gre_keymap_flush b) Let's say we find that the keymap list is not empty. This means netns still has a conntrack associated with gre, in which case we should not free its memory, because this will lead to a double free and related crashes. However I doubt it could have gone unnoticed for years, obviously this does not happen in real life. So I think we can remove both nf_ct_gre_keymap_flush() and nf_conntrack_proto_pernet_fini(). Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>