3.16.52-rc1 review patch. If anyone has any objections, please let me know.
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From: Florian Westphal fw@strlen.de
commit e23ed762db7ed1950a6408c3be80bc56909ab3d4 upstream.
Removing the ipset module leaves a small window where one cpu performs module removal while another runs a command like 'ipset flush'.
ipset uses net_generic(), unregistering the pernet ops frees this storage area.
Fix it by first removing the user-visible api handlers and the pernet ops last.
Fixes: 1785e8f473082 ("netfiler: ipset: Add net namespace for ipset") Reported-by: Li Shuang shuali@redhat.com Signed-off-by: Florian Westphal fw@strlen.de Acked-by: Jozsef Kadlecsik kadlec@blackhole.kfki.hu Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- --- a/net/netfilter/ipset/ip_set_core.c +++ b/net/netfilter/ipset/ip_set_core.c @@ -1982,24 +1982,28 @@ static struct pernet_operations ip_set_n static int __init ip_set_init(void) { - int ret = nfnetlink_subsys_register(&ip_set_netlink_subsys); + int ret = register_pernet_subsys(&ip_set_net_ops); + + if (ret) { + pr_err("ip_set: cannot register pernet_subsys.\n"); + return ret; + } + + ret = nfnetlink_subsys_register(&ip_set_netlink_subsys); if (ret != 0) { pr_err("ip_set: cannot register with nfnetlink.\n"); + unregister_pernet_subsys(&ip_set_net_ops); return ret; } + ret = nf_register_sockopt(&so_set); if (ret != 0) { pr_err("SO_SET registry failed: %d\n", ret); nfnetlink_subsys_unregister(&ip_set_netlink_subsys); + unregister_pernet_subsys(&ip_set_net_ops); return ret; } - ret = register_pernet_subsys(&ip_set_net_ops); - if (ret) { - pr_err("ip_set: cannot register pernet_subsys.\n"); - nf_unregister_sockopt(&so_set); - nfnetlink_subsys_unregister(&ip_set_netlink_subsys); - return ret; - } + pr_info("ip_set: protocol %u\n", IPSET_PROTOCOL); return 0; } @@ -2007,9 +2011,10 @@ ip_set_init(void) static void __exit ip_set_fini(void) { - unregister_pernet_subsys(&ip_set_net_ops); nf_unregister_sockopt(&so_set); nfnetlink_subsys_unregister(&ip_set_netlink_subsys); + + unregister_pernet_subsys(&ip_set_net_ops); pr_debug("these are the famous last words\n"); }