From 3ece5c4bf601ca751d5524a9c5c8917723e9e5f2 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 23 Sep 2021 16:44:34 +0200 Subject: netfilter: conntrack: fix boot failure with nf_conntrack.enable_hooks=1 [ Upstream commit 339031bafe6b281cf2dcb8364217288b9fdab555 ] This is a revert of 7b1957b049 ("netfilter: nf_defrag_ipv4: use net_generic infra") and a partial revert of 8b0adbe3e3 ("netfilter: nf_defrag_ipv6: use net_generic infra"). If conntrack is builtin and kernel is booted with: nf_conntrack.enable_hooks=1 .... kernel will fail to boot due to a NULL deref in nf_defrag_ipv4_enable(): Its called before the ipv4 defrag initcall is made, so net_generic() returns NULL. To resolve this, move the user refcount back to struct net so calls to those functions are possible even before their initcalls have run. Fixes: 7b1957b04956 ("netfilter: nf_defrag_ipv4: use net_generic infra") Fixes: 8b0adbe3e38d ("netfilter: nf_defrag_ipv6: use net_generic infra"). Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/ipv6/netfilter/nf_conntrack_reasm.c | 2 +- net/ipv6/netfilter/nf_defrag_ipv6_hooks.c | 25 +++++++++---------------- 2 files changed, 10 insertions(+), 17 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c index a0108415275f..5c47be29b9ee 100644 --- a/net/ipv6/netfilter/nf_conntrack_reasm.c +++ b/net/ipv6/netfilter/nf_conntrack_reasm.c @@ -33,7 +33,7 @@ static const char nf_frags_cache_name[] = "nf-frags"; -unsigned int nf_frag_pernet_id __read_mostly; +static unsigned int nf_frag_pernet_id __read_mostly; static struct inet_frags nf_frags; static struct nft_ct_frag6_pernet *nf_frag_pernet(struct net *net) diff --git a/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c index e8a59d8bf2ad..cb4eb1d2c620 100644 --- a/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c +++ b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c @@ -25,8 +25,6 @@ #include #include -extern unsigned int nf_frag_pernet_id; - static DEFINE_MUTEX(defrag6_mutex); static enum ip6_defrag_users nf_ct6_defrag_user(unsigned int hooknum, @@ -91,12 +89,10 @@ static const struct nf_hook_ops ipv6_defrag_ops[] = { static void __net_exit defrag6_net_exit(struct net *net) { - struct nft_ct_frag6_pernet *nf_frag = net_generic(net, nf_frag_pernet_id); - - if (nf_frag->users) { + if (net->nf.defrag_ipv6_users) { nf_unregister_net_hooks(net, ipv6_defrag_ops, ARRAY_SIZE(ipv6_defrag_ops)); - nf_frag->users = 0; + net->nf.defrag_ipv6_users = 0; } } @@ -134,24 +130,23 @@ static void __exit nf_defrag_fini(void) int nf_defrag_ipv6_enable(struct net *net) { - struct nft_ct_frag6_pernet *nf_frag = net_generic(net, nf_frag_pernet_id); int err = 0; mutex_lock(&defrag6_mutex); - if (nf_frag->users == UINT_MAX) { + if (net->nf.defrag_ipv6_users == UINT_MAX) { err = -EOVERFLOW; goto out_unlock; } - if (nf_frag->users) { - nf_frag->users++; + if (net->nf.defrag_ipv6_users) { + net->nf.defrag_ipv6_users++; goto out_unlock; } err = nf_register_net_hooks(net, ipv6_defrag_ops, ARRAY_SIZE(ipv6_defrag_ops)); if (err == 0) - nf_frag->users = 1; + net->nf.defrag_ipv6_users = 1; out_unlock: mutex_unlock(&defrag6_mutex); @@ -161,12 +156,10 @@ EXPORT_SYMBOL_GPL(nf_defrag_ipv6_enable); void nf_defrag_ipv6_disable(struct net *net) { - struct nft_ct_frag6_pernet *nf_frag = net_generic(net, nf_frag_pernet_id); - mutex_lock(&defrag6_mutex); - if (nf_frag->users) { - nf_frag->users--; - if (nf_frag->users == 0) + if (net->nf.defrag_ipv6_users) { + net->nf.defrag_ipv6_users--; + if (net->nf.defrag_ipv6_users == 0) nf_unregister_net_hooks(net, ipv6_defrag_ops, ARRAY_SIZE(ipv6_defrag_ops)); } -- cgit v1.2.3