Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net, they are:

1) Unaligned atomic access in ipset, from Russell King.

2) Missing module description, from Rob Gill.

3) Patches to fix a module unload causing NULL pointer dereference in
   xtables, from David Wilder. For the record, I posting here his cover
   letter explaining the problem:

    A crash happened on ppc64le when running ltp network tests triggered by
    "rmmod iptable_mangle".

    See previous discussion in this thread:
    https://lists.openwall.net/netdev/2020/06/03/161 .

    In the crash I found in iptable_mangle_hook() that
    state->net->ipv4.iptable_mangle=NULL causing a NULL pointer dereference.
    net->ipv4.iptable_mangle is set to NULL in +iptable_mangle_net_exit() and
    called when ip_mangle modules is unloaded. A rmmod task was found running
    in the crash dump.  A 2nd crash showed the same problem when running
    "rmmod iptable_filter" (net->ipv4.iptable_filter=NULL).

    To fix this I added .pre_exit hook in all iptable_foo.c. The pre_exit will
    un-register the underlying hook and exit would do the table freeing. The
    netns core does an unconditional +synchronize_rcu after the pre_exit hooks
    insuring no packets are in flight that have picked up the pointer before
    completing the un-register.

    These patches include changes for both iptables and ip6tables.

    We tested this fix with ltp running iptables01.sh and iptables01.sh -6 a
    loop for 72 hours.

4) Add a selftest for conntrack helper assignment, from Florian Westphal.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/netfilter_ipv4/ip_tables.h b/include/linux/netfilter_ipv4/ip_tables.h
index b394bd4f68a3..c4676d6feeff 100644
--- a/include/linux/netfilter_ipv4/ip_tables.h
+++ b/include/linux/netfilter_ipv4/ip_tables.h
@@ -25,6 +25,12 @@
 int ipt_register_table(struct net *net, const struct xt_table *table,
 		       const struct ipt_replace *repl,
 		       const struct nf_hook_ops *ops, struct xt_table **res);
+
+void ipt_unregister_table_pre_exit(struct net *net, struct xt_table *table,
+		       const struct nf_hook_ops *ops);
+
+void ipt_unregister_table_exit(struct net *net, struct xt_table *table);
+
 void ipt_unregister_table(struct net *net, struct xt_table *table,
 			  const struct nf_hook_ops *ops);
 
diff --git a/include/linux/netfilter_ipv6/ip6_tables.h b/include/linux/netfilter_ipv6/ip6_tables.h
index 8225f7821a29..1547d5f9ae06 100644
--- a/include/linux/netfilter_ipv6/ip6_tables.h
+++ b/include/linux/netfilter_ipv6/ip6_tables.h
@@ -29,6 +29,9 @@ int ip6t_register_table(struct net *net, const struct xt_table *table,
 			const struct nf_hook_ops *ops, struct xt_table **res);
 void ip6t_unregister_table(struct net *net, struct xt_table *table,
 			   const struct nf_hook_ops *ops);
+void ip6t_unregister_table_pre_exit(struct net *net, struct xt_table *table,
+				    const struct nf_hook_ops *ops);
+void ip6t_unregister_table_exit(struct net *net, struct xt_table *table);
 extern unsigned int ip6t_do_table(struct sk_buff *skb,
 				  const struct nf_hook_state *state,
 				  struct xt_table *table);