diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c index fd62a41d69cc..6dc72a815f77 100644 --- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c +++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c @@ -133,6 +133,7 @@ static unsigned int ipv4_conntrack_help(unsigned int hooknum, struct nf_conn *ct; enum ip_conntrack_info ctinfo; struct nf_conn_help *help; + struct nf_conntrack_helper *helper; /* This is where we call the helper: as the packet goes out. */ ct = nf_ct_get(*pskb, &ctinfo); @@ -140,12 +141,14 @@ static unsigned int ipv4_conntrack_help(unsigned int hooknum, return NF_ACCEPT; help = nfct_help(ct); - if (!help || !help->helper) + if (!help) return NF_ACCEPT; - - return help->helper->help(pskb, - skb_network_offset(*pskb) + ip_hdrlen(*pskb), - ct, ctinfo); + /* rcu_read_lock()ed by nf_hook_slow */ + helper = rcu_dereference(help->helper); + if (!helper) + return NF_ACCEPT; + return helper->help(pskb, skb_network_offset(*pskb) + ip_hdrlen(*pskb), + ct, ctinfo); } static unsigned int ipv4_conntrack_defrag(unsigned int hooknum, diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c index dc442fb791b0..1b1797f1f33d 100644 --- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c +++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c @@ -160,6 +160,7 @@ static unsigned int ipv6_confirm(unsigned int hooknum, { struct nf_conn *ct; struct nf_conn_help *help; + struct nf_conntrack_helper *helper; enum ip_conntrack_info ctinfo; unsigned int ret, protoff; unsigned int extoff = (u8 *)(ipv6_hdr(*pskb) + 1) - (*pskb)->data; @@ -172,7 +173,11 @@ static unsigned int ipv6_confirm(unsigned int hooknum, goto out; help = nfct_help(ct); - if (!help || !help->helper) + if (!help) + goto out; + /* rcu_read_lock()ed by nf_hook_slow */ + helper = rcu_dereference(help->helper); + if (!helper) goto out; protoff = nf_ct_ipv6_skip_exthdr(*pskb, extoff, &pnum, @@ -182,7 +187,7 @@ static unsigned int ipv6_confirm(unsigned int hooknum, return NF_ACCEPT; } - ret = help->helper->help(pskb, protoff, ct, ctinfo); + ret = helper->help(pskb, protoff, ct, ctinfo); if (ret != NF_ACCEPT) return ret; out: diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 483e927a9ca4..7a15e30356f2 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -350,9 +350,15 @@ static void death_by_timeout(unsigned long ul_conntrack) { struct nf_conn *ct = (void *)ul_conntrack; struct nf_conn_help *help = nfct_help(ct); + struct nf_conntrack_helper *helper; - if (help && help->helper && help->helper->destroy) - help->helper->destroy(ct); + if (help) { + rcu_read_lock(); + helper = rcu_dereference(help->helper); + if (helper && helper->destroy) + helper->destroy(ct); + rcu_read_unlock(); + } write_lock_bh(&nf_conntrack_lock); /* Inside lock so preempt is disabled on module removal path. @@ -661,6 +667,7 @@ init_conntrack(const struct nf_conntrack_tuple *tuple, unsigned int dataoff) { struct nf_conn *conntrack; + struct nf_conn_help *help; struct nf_conntrack_tuple repl_tuple; struct nf_conntrack_expect *exp; u_int32_t features = 0; @@ -691,6 +698,7 @@ init_conntrack(const struct nf_conntrack_tuple *tuple, write_lock_bh(&nf_conntrack_lock); exp = find_expectation(tuple); + help = nfct_help(conntrack); if (exp) { DEBUGP("conntrack: expectation arrives ct=%p exp=%p\n", conntrack, exp); @@ -698,7 +706,7 @@ init_conntrack(const struct nf_conntrack_tuple *tuple, __set_bit(IPS_EXPECTED_BIT, &conntrack->status); conntrack->master = exp->master; if (exp->helper) - nfct_help(conntrack)->helper = exp->helper; + rcu_assign_pointer(help->helper, exp->helper); #ifdef CONFIG_NF_CONNTRACK_MARK conntrack->mark = exp->master->mark; #endif @@ -708,10 +716,11 @@ init_conntrack(const struct nf_conntrack_tuple *tuple, nf_conntrack_get(&conntrack->master->ct_general); NF_CT_STAT_INC(expect_new); } else { - struct nf_conn_help *help = nfct_help(conntrack); - - if (help) - help->helper = __nf_ct_helper_find(&repl_tuple); + if (help) { + /* not in hash table yet, so not strictly necessary */ + rcu_assign_pointer(help->helper, + __nf_ct_helper_find(&repl_tuple)); + } NF_CT_STAT_INC(new); } @@ -893,7 +902,8 @@ void nf_conntrack_alter_reply(struct nf_conn *ct, helper = __nf_ct_helper_find(newreply); if (helper) memset(&help->help, 0, sizeof(help->help)); - help->helper = helper; + /* not in hash table yet, so not strictly necessary */ + rcu_assign_pointer(help->helper, helper); } write_unlock_bh(&nf_conntrack_lock); } diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c index 117cbfdb910c..504fb6c083f9 100644 --- a/net/netfilter/nf_conntrack_expect.c +++ b/net/netfilter/nf_conntrack_expect.c @@ -337,6 +337,10 @@ int nf_conntrack_expect_related(struct nf_conntrack_expect *expect) NF_CT_ASSERT(master_help); write_lock_bh(&nf_conntrack_lock); + if (!master_help->helper) { + ret = -ESHUTDOWN; + goto out; + } list_for_each_entry(i, &nf_conntrack_expect_list, list) { if (expect_matches(i, expect)) { /* Refresh timer: if it's dying, ignore.. */ diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c index 0743be4434b0..f868b7fbd9b4 100644 --- a/net/netfilter/nf_conntrack_helper.c +++ b/net/netfilter/nf_conntrack_helper.c @@ -93,7 +93,7 @@ static inline int unhelp(struct nf_conntrack_tuple_hash *i, if (help && help->helper == me) { nf_conntrack_event(IPCT_HELPER, ct); - help->helper = NULL; + rcu_assign_pointer(help->helper, NULL); } return 0; } diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index d6d39e241327..3f73327794ab 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -171,21 +171,29 @@ ctnetlink_dump_helpinfo(struct sk_buff *skb, const struct nf_conn *ct) { struct nfattr *nest_helper; const struct nf_conn_help *help = nfct_help(ct); + struct nf_conntrack_helper *helper; - if (!help || !help->helper) + if (!help) return 0; - nest_helper = NFA_NEST(skb, CTA_HELP); - NFA_PUT(skb, CTA_HELP_NAME, strlen(help->helper->name), help->helper->name); + rcu_read_lock(); + helper = rcu_dereference(help->helper); + if (!helper) + goto out; - if (help->helper->to_nfattr) - help->helper->to_nfattr(skb, ct); + nest_helper = NFA_NEST(skb, CTA_HELP); + NFA_PUT(skb, CTA_HELP_NAME, strlen(helper->name), helper->name); + + if (helper->to_nfattr) + helper->to_nfattr(skb, ct); NFA_NEST_END(skb, nest_helper); - +out: + rcu_read_unlock(); return 0; nfattr_failure: + rcu_read_unlock(); return -1; } @@ -842,7 +850,7 @@ ctnetlink_change_helper(struct nf_conn *ct, struct nfattr *cda[]) if (help && help->helper) { /* we had a helper before ... */ nf_ct_remove_expectations(ct); - help->helper = NULL; + rcu_assign_pointer(help->helper, NULL); } return 0; @@ -866,7 +874,7 @@ ctnetlink_change_helper(struct nf_conn *ct, struct nfattr *cda[]) /* need to zero data of old helper */ memset(&help->help, 0, sizeof(help->help)); - help->helper = helper; + rcu_assign_pointer(help->helper, helper); return 0; } @@ -950,6 +958,7 @@ ctnetlink_create_conntrack(struct nfattr *cda[], struct nf_conn *ct; int err = -EINVAL; struct nf_conn_help *help; + struct nf_conntrack_helper *helper = NULL; ct = nf_conntrack_alloc(otuple, rtuple); if (ct == NULL || IS_ERR(ct)) @@ -980,14 +989,17 @@ ctnetlink_create_conntrack(struct nfattr *cda[], #endif help = nfct_help(ct); - if (help) - help->helper = nf_ct_helper_find_get(rtuple); + if (help) { + helper = nf_ct_helper_find_get(rtuple); + /* not in hash table yet so not strictly necessary */ + rcu_assign_pointer(help->helper, helper); + } add_timer(&ct->timeout); nf_conntrack_hash_insert(ct); - if (help && help->helper) - nf_ct_helper_put(help->helper); + if (helper) + nf_ct_helper_put(helper); return 0; diff --git a/net/netfilter/nf_conntrack_proto_gre.c b/net/netfilter/nf_conntrack_proto_gre.c index 5434472420fe..339c397d1b5f 100644 --- a/net/netfilter/nf_conntrack_proto_gre.c +++ b/net/netfilter/nf_conntrack_proto_gre.c @@ -100,7 +100,6 @@ int nf_ct_gre_keymap_add(struct nf_conn *ct, enum ip_conntrack_dir dir, struct nf_conn_help *help = nfct_help(ct); struct nf_ct_gre_keymap **kmp, *km; - BUG_ON(strcmp(help->helper->name, "pptp")); kmp = &help->help.ct_pptp_info.keymap[dir]; if (*kmp) { /* check whether it's a retransmission */ @@ -137,7 +136,6 @@ void nf_ct_gre_keymap_destroy(struct nf_conn *ct) enum ip_conntrack_dir dir; DEBUGP("entering for ct %p\n", ct); - BUG_ON(strcmp(help->helper->name, "pptp")); write_lock_bh(&nf_ct_gre_lock); for (dir = IP_CT_DIR_ORIGINAL; dir < IP_CT_DIR_MAX; dir++) {