Merge tag 'nf-26-05-08' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf

Pablo Neira Ayuso says:

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

The following batch contains Netfilter fixes for net:

1) Allow initial x_tables table replacement without emitting an audit
   log message. Delay the register message until after hooks are wired up
   to avoid unnecessary unregister logs during error unwinding.

2) Fix a NULL dereference by allocating hook ops before adding the
   table to the per-netns list. Use `synchronize_rcu()` during error
   unwinding to ensure the table stops processing packets before
   teardown. Defer audit log register message until all operations
   succeed.

3) Refactor xtables to use a single `xt_unregister_table_pre_exit`
   function. Eliminate code duplication by centralizing table
   unregistration logic within the xtables core. ebtables cannot be
   changed due to incompatibility.

4) Unregister xtables templates before module removal. This prevents
   a race condition where userspace instantiates a new table after the
   pernet unreg removed the current table.

5) Add `xtables_unregister_table_exit` to fully unregister netfilter
   tables during module removal. Unlink the table from dying lists,
   then free hook operations.

6) Implement a two-stage removal scheme for ebtables following the
   x_tables pattern. Assign table->ops while holding the ebt mutex to
   prevent exposing partially-filled structures.

7) Fix ebtables module initialization race. Register the template last
   in table initialization functions. Prevent table instantiation before
   pernet operations are available.

8) Fix a race condition in x_tables module initialization. Ensure
   pernet ops are fully set up before exposing the table to userspace.

9) Fix a race condition in ebtables module initialization, similar to
   previous patch.

10) Restore propagation of helper to expected connection, this is a
    fix-for-recent-fix.

11) Validate that the expectation tuple and mask netlink attributes are
    present when adding expectation via nfqueue, this fixes a possible
    null-ptr-deref.

12) Fix possible rare memleak in the SIP helper in case helper has been
    detached from conntrack entry, from Li Xiasong.

13) Fix refcount leak in nft_ct when creating custom expectation, also
    from Li Xiason.

Patches 1-9 from Florian Westphal.

10) Restore propagation of helper to expected connection, this is a
    fix-for-recent-fix.

11) Check that tuple and mask netlink attributes are set when creating an
    expectation via nfqueue.

* tag 'nf-26-05-08' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: nft_ct: fix missing expect put in obj eval
  netfilter: nf_conntrack_sip: get helper before allocating expectation
  netfilter: ctnetlink: check tuple and mask in expectations created via nfqueue
  netfilter: nf_conntrack_expect: restore helper propagation via expectation
  netfilter: bridge: eb_tables: close module init race
  netfilter: x_tables: close dangling table module init race
  netfilter: ebtables: close dangling table module init race
  netfilter: ebtables: move to two-stage removal scheme
  netfilter: x_tables: add and use xtables_unregister_table_exit
  netfilter: x_tables: unregister the templates first
  netfilter: x_tables: add and use xt_unregister_table_pre_exit
  netfilter: x_tables: allocate hook ops while under mutex
  netfilter: x_tables: allow initial table replace without emitting audit log message
====================

Link: https://patch.msgid.link/20260507234509.603182-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

5 files changed, 7 insertions, 5 deletions

diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index a81b46af5118..5a1c5c336fa4 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -305,9 +305,11 @@ struct xt_counters *xt_counters_alloc(unsigned int counters);
 
 struct xt_table *xt_register_table(struct net *net,
 				   const struct xt_table *table,
+				   const struct nf_hook_ops *template_ops,
 				   struct xt_table_info *bootstrap,
 				   struct xt_table_info *newinfo);
-void *xt_unregister_table(struct xt_table *table);
+void xt_unregister_table_pre_exit(struct net *net, u8 af, const char *name);
+struct xt_table *xt_unregister_table_exit(struct net *net, u8 af, const char *name);
 
 struct xt_table_info *xt_replace_table(struct xt_table *table,
 				       unsigned int num_counters,
diff --git a/include/linux/netfilter_arp/arp_tables.h b/include/linux/netfilter_arp/arp_tables.h
index a40aaf645fa4..05631a25e622 100644
--- a/include/linux/netfilter_arp/arp_tables.h
+++ b/include/linux/netfilter_arp/arp_tables.h
@@ -53,7 +53,6 @@ int arpt_register_table(struct net *net, const struct xt_table *table,
 			const struct arpt_replace *repl,
 			const struct nf_hook_ops *ops);
 void arpt_unregister_table(struct net *net, const char *name);
-void arpt_unregister_table_pre_exit(struct net *net, const char *name);
 extern unsigned int arpt_do_table(void *priv, struct sk_buff *skb,
 				  const struct nf_hook_state *state);
 
diff --git a/include/linux/netfilter_ipv4/ip_tables.h b/include/linux/netfilter_ipv4/ip_tables.h
index 132b0e4a6d4d..13593391d605 100644
--- a/include/linux/netfilter_ipv4/ip_tables.h
+++ b/include/linux/netfilter_ipv4/ip_tables.h
@@ -26,7 +26,6 @@ int ipt_register_table(struct net *net, const struct xt_table *table,
 		       const struct ipt_replace *repl,
 		       const struct nf_hook_ops *ops);
 
-void ipt_unregister_table_pre_exit(struct net *net, const char *name);
 void ipt_unregister_table_exit(struct net *net, const char *name);
 
 /* Standard entry. */
diff --git a/include/linux/netfilter_ipv6/ip6_tables.h b/include/linux/netfilter_ipv6/ip6_tables.h
index 8b8885a73c76..c6d5b927830d 100644
--- a/include/linux/netfilter_ipv6/ip6_tables.h
+++ b/include/linux/netfilter_ipv6/ip6_tables.h
@@ -27,7 +27,6 @@ extern void *ip6t_alloc_initial_table(const struct xt_table *);
 int ip6t_register_table(struct net *net, const struct xt_table *table,
 			const struct ip6t_replace *repl,
 			const struct nf_hook_ops *ops);
-void ip6t_unregister_table_pre_exit(struct net *net, const char *name);
 void ip6t_unregister_table_exit(struct net *net, const char *name);
 extern unsigned int ip6t_do_table(void *priv, struct sk_buff *skb,
 				  const struct nf_hook_state *state);
diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h
index e9a8350e7ccf..80f50fd0f7ad 100644
--- a/include/net/netfilter/nf_conntrack_expect.h
+++ b/include/net/netfilter/nf_conntrack_expect.h
@@ -45,9 +45,12 @@ struct nf_conntrack_expect {
 	void (*expectfn)(struct nf_conn *new,
 			 struct nf_conntrack_expect *this);
 
-	/* Helper to assign to new connection */
+	/* Helper that created this expectation */
 	struct nf_conntrack_helper __rcu *helper;
 
+	/* Helper to assign to new connection */
+	struct nf_conntrack_helper __rcu *assign_helper;
+
 	/* The conntrack of the master connection */
 	struct nf_conn *master;