diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h index de2f956abf34..24cf3d2d9745 100644 --- a/include/net/netfilter/nf_conntrack_helper.h +++ b/include/net/netfilter/nf_conntrack_helper.h @@ -155,6 +155,7 @@ void nf_ct_helper_log(struct sk_buff *skb, const struct nf_conn *ct, void nf_ct_helper_expectfn_register(struct nf_ct_helper_expectfn *n); void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n); +void nf_ct_helper_expectfn_destroy(const struct nf_ct_helper_expectfn *n); struct nf_ct_helper_expectfn * nf_ct_helper_expectfn_find_by_name(const char *name); struct nf_ct_helper_expectfn * diff --git a/net/ipv4/netfilter/nf_nat_h323.c b/net/ipv4/netfilter/nf_nat_h323.c index faee20af4856..10e1b0837731 100644 --- a/net/ipv4/netfilter/nf_nat_h323.c +++ b/net/ipv4/netfilter/nf_nat_h323.c @@ -555,6 +555,8 @@ static void __exit nf_nat_h323_fini(void) nf_ct_helper_expectfn_unregister(&q931_nat); nf_ct_helper_expectfn_unregister(&callforwarding_nat); synchronize_rcu(); + nf_ct_helper_expectfn_destroy(&q931_nat); + nf_ct_helper_expectfn_destroy(&callforwarding_nat); } /****************************************************************************/ diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c index 17e971bd4c74..2c5a71735561 100644 --- a/net/netfilter/nf_conntrack_helper.c +++ b/net/netfilter/nf_conntrack_helper.c @@ -283,6 +283,25 @@ void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n) } EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_unregister); +static bool expect_iter_expectfn(struct nf_conntrack_expect *exp, void *data) +{ + const struct nf_ct_helper_expectfn *n = data; + + /* Relies on registered expectfn descriptors having unique ->expectfn + * pointers, which holds for the in-tree NAT helpers. + */ + return exp->expectfn == n->expectfn; +} + +/* Destroy expectations still pointing at @n->expectfn; call after the + * caller's RCU grace period so none outlives the (often modular) callback. + */ +void nf_ct_helper_expectfn_destroy(const struct nf_ct_helper_expectfn *n) +{ + nf_ct_expect_iterate_destroy(expect_iter_expectfn, (void *)n); +} +EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_destroy); + /* Caller should hold the rcu lock */ struct nf_ct_helper_expectfn * nf_ct_helper_expectfn_find_by_name(const char *name) diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index 74ec224ce0d6..2bbf5163c0e2 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -1341,6 +1341,7 @@ static int __init nf_nat_init(void) RCU_INIT_POINTER(nf_nat_hook, NULL); nf_ct_helper_expectfn_unregister(&follow_master_nat); synchronize_net(); + nf_ct_helper_expectfn_destroy(&follow_master_nat); unregister_pernet_subsys(&nat_net_ops); kvfree(nf_nat_bysource); } @@ -1358,6 +1359,7 @@ static void __exit nf_nat_cleanup(void) RCU_INIT_POINTER(nf_nat_hook, NULL); synchronize_net(); + nf_ct_helper_expectfn_destroy(&follow_master_nat); kvfree(nf_nat_bysource); unregister_pernet_subsys(&nat_net_ops); } diff --git a/net/netfilter/nf_nat_sip.c b/net/netfilter/nf_nat_sip.c index 9fbfc6bff0c2..00838c0cc5bb 100644 --- a/net/netfilter/nf_nat_sip.c +++ b/net/netfilter/nf_nat_sip.c @@ -655,6 +655,7 @@ static void __exit nf_nat_sip_fini(void) RCU_INIT_POINTER(nf_nat_sip_hooks, NULL); nf_ct_helper_expectfn_unregister(&sip_nat); synchronize_rcu(); + nf_ct_helper_expectfn_destroy(&sip_nat); } static const struct nf_nat_sip_hooks sip_hooks = {