From b7e8590987aa94c9dc51518fad0e58cb887b1db5 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 30 Mar 2026 14:16:34 +0200 Subject: netfilter: ipset: use nla_strcmp for IPSET_ATTR_NAME attr IPSET_ATTR_NAME and IPSET_ATTR_NAMEREF are of NLA_STRING type, they cannot be treated like a c-string. They either have to be switched to NLA_NUL_STRING, or the compare operations need to use the nla functions. Fixes: f830837f0eed ("netfilter: ipset: list:set set type support") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/ipset/ip_set.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/netfilter') diff --git a/include/linux/netfilter/ipset/ip_set.h b/include/linux/netfilter/ipset/ip_set.h index e9f4f845d760..b98331572ad2 100644 --- a/include/linux/netfilter/ipset/ip_set.h +++ b/include/linux/netfilter/ipset/ip_set.h @@ -309,7 +309,7 @@ enum { /* register and unregister set references */ extern ip_set_id_t ip_set_get_byname(struct net *net, - const char *name, struct ip_set **set); + const struct nlattr *name, struct ip_set **set); extern void ip_set_put_byindex(struct net *net, ip_set_id_t index); extern void ip_set_name_byindex(struct net *net, ip_set_id_t index, char *name); extern ip_set_id_t ip_set_nfnl_get_byindex(struct net *net, ip_set_id_t index); -- cgit v1.2.3 From 6e6f2b9b3375cc0e6b8567d31ae7d3b2d910582f Mon Sep 17 00:00:00 2001 From: Sun Jian Date: Tue, 3 Mar 2026 18:15:25 +0800 Subject: netfilter: use function typedefs for __rcu NAT helper hook pointers After commit 07919126ecfc ("netfilter: annotate NAT helper hook pointers with __rcu"), sparse can warn about type/address-space mismatches when RCU-dereferencing NAT helper hook function pointers. The hooks are __rcu-annotated and accessed via rcu_dereference(), but the combination of complex function pointer declarators and the WRITE_ONCE() machinery used by RCU_INIT_POINTER()/rcu_assign_pointer() can confuse sparse and trigger false positives. Introduce typedefs for the NAT helper function types, so __rcu applies to a simple "fn_t __rcu *" pointer form. Also replace local typeof(hook) variables with "fn_t *" to avoid propagating __rcu address space into temporaries. No functional change intended. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202603022359.3dGE9fwI-lkp@intel.com/ Signed-off-by: Sun Jian Signed-off-by: Florian Westphal --- include/linux/netfilter/nf_conntrack_amanda.h | 15 +++++++++------ include/linux/netfilter/nf_conntrack_ftp.h | 17 ++++++++++------- include/linux/netfilter/nf_conntrack_irc.h | 15 +++++++++------ include/linux/netfilter/nf_conntrack_snmp.h | 11 +++++++---- include/linux/netfilter/nf_conntrack_tftp.h | 9 ++++++--- 5 files changed, 41 insertions(+), 26 deletions(-) (limited to 'include/linux/netfilter') diff --git a/include/linux/netfilter/nf_conntrack_amanda.h b/include/linux/netfilter/nf_conntrack_amanda.h index dfe89f38d1f7..1719987e8fd8 100644 --- a/include/linux/netfilter/nf_conntrack_amanda.h +++ b/include/linux/netfilter/nf_conntrack_amanda.h @@ -7,10 +7,13 @@ #include #include -extern unsigned int (__rcu *nf_nat_amanda_hook)(struct sk_buff *skb, - enum ip_conntrack_info ctinfo, - unsigned int protoff, - unsigned int matchoff, - unsigned int matchlen, - struct nf_conntrack_expect *exp); +typedef unsigned int +nf_nat_amanda_hook_fn(struct sk_buff *skb, + enum ip_conntrack_info ctinfo, + unsigned int protoff, + unsigned int matchoff, + unsigned int matchlen, + struct nf_conntrack_expect *exp); + +extern nf_nat_amanda_hook_fn __rcu *nf_nat_amanda_hook; #endif /* _NF_CONNTRACK_AMANDA_H */ diff --git a/include/linux/netfilter/nf_conntrack_ftp.h b/include/linux/netfilter/nf_conntrack_ftp.h index f31292642035..7b62446ccec4 100644 --- a/include/linux/netfilter/nf_conntrack_ftp.h +++ b/include/linux/netfilter/nf_conntrack_ftp.h @@ -26,11 +26,14 @@ struct nf_ct_ftp_master { /* For NAT to hook in when we find a packet which describes what other * connection we should expect. */ -extern unsigned int (__rcu *nf_nat_ftp_hook)(struct sk_buff *skb, - enum ip_conntrack_info ctinfo, - enum nf_ct_ftp_type type, - unsigned int protoff, - unsigned int matchoff, - unsigned int matchlen, - struct nf_conntrack_expect *exp); +typedef unsigned int +nf_nat_ftp_hook_fn(struct sk_buff *skb, + enum ip_conntrack_info ctinfo, + enum nf_ct_ftp_type type, + unsigned int protoff, + unsigned int matchoff, + unsigned int matchlen, + struct nf_conntrack_expect *exp); + +extern nf_nat_ftp_hook_fn __rcu *nf_nat_ftp_hook; #endif /* _NF_CONNTRACK_FTP_H */ diff --git a/include/linux/netfilter/nf_conntrack_irc.h b/include/linux/netfilter/nf_conntrack_irc.h index 4f3ca5621998..ce07250afb4e 100644 --- a/include/linux/netfilter/nf_conntrack_irc.h +++ b/include/linux/netfilter/nf_conntrack_irc.h @@ -8,11 +8,14 @@ #define IRC_PORT 6667 -extern unsigned int (__rcu *nf_nat_irc_hook)(struct sk_buff *skb, - enum ip_conntrack_info ctinfo, - unsigned int protoff, - unsigned int matchoff, - unsigned int matchlen, - struct nf_conntrack_expect *exp); +typedef unsigned int +nf_nat_irc_hook_fn(struct sk_buff *skb, + enum ip_conntrack_info ctinfo, + unsigned int protoff, + unsigned int matchoff, + unsigned int matchlen, + struct nf_conntrack_expect *exp); + +extern nf_nat_irc_hook_fn __rcu *nf_nat_irc_hook; #endif /* _NF_CONNTRACK_IRC_H */ diff --git a/include/linux/netfilter/nf_conntrack_snmp.h b/include/linux/netfilter/nf_conntrack_snmp.h index 99107e4f5234..bb39f04a9977 100644 --- a/include/linux/netfilter/nf_conntrack_snmp.h +++ b/include/linux/netfilter/nf_conntrack_snmp.h @@ -5,9 +5,12 @@ #include #include -extern int (__rcu *nf_nat_snmp_hook)(struct sk_buff *skb, - unsigned int protoff, - struct nf_conn *ct, - enum ip_conntrack_info ctinfo); +typedef int +nf_nat_snmp_hook_fn(struct sk_buff *skb, + unsigned int protoff, + struct nf_conn *ct, + enum ip_conntrack_info ctinfo); + +extern nf_nat_snmp_hook_fn __rcu *nf_nat_snmp_hook; #endif /* _NF_CONNTRACK_SNMP_H */ diff --git a/include/linux/netfilter/nf_conntrack_tftp.h b/include/linux/netfilter/nf_conntrack_tftp.h index 1490b68dd7d1..90b334bbce3c 100644 --- a/include/linux/netfilter/nf_conntrack_tftp.h +++ b/include/linux/netfilter/nf_conntrack_tftp.h @@ -19,8 +19,11 @@ struct tftphdr { #define TFTP_OPCODE_ACK 4 #define TFTP_OPCODE_ERROR 5 -extern unsigned int (__rcu *nf_nat_tftp_hook)(struct sk_buff *skb, - enum ip_conntrack_info ctinfo, - struct nf_conntrack_expect *exp); +typedef unsigned int +nf_nat_tftp_hook_fn(struct sk_buff *skb, + enum ip_conntrack_info ctinfo, + struct nf_conntrack_expect *exp); + +extern nf_nat_tftp_hook_fn __rcu *nf_nat_tftp_hook; #endif /* _NF_CONNTRACK_TFTP_H */ -- cgit v1.2.3 From 6813985ca456d1f5677ad9554f55805cbf27e16f Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 28 Apr 2026 17:35:18 +0200 Subject: netfilter: x_tables: add .check_hooks to matches and targets Add a new .check_hooks interface for checking if the match/target is used from the validate hook according to its configuration. Move existing conditional hook check based on the match/target configuration from .checkentry to .check_hooks for the following matches/targets: - addrtype - devgroup - physdev - policy - set - TCPMSS - SET This is a preparation patch to fix nft_compat, not functional changes are intended. Based on patch from Florian Westphal. Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/x_tables.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/netfilter') diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 77c778d84d4c..a81b46af5118 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -146,6 +146,9 @@ struct xt_match { /* Called when user tries to insert an entry of this type. */ int (*checkentry)(const struct xt_mtchk_param *); + /* Called to validate hooks based on the match configuration. */ + int (*check_hooks)(const struct xt_mtchk_param *); + /* Called when entry of this type deleted. */ void (*destroy)(const struct xt_mtdtor_param *); #ifdef CONFIG_NETFILTER_XTABLES_COMPAT @@ -187,6 +190,9 @@ struct xt_target { /* Should return 0 on success or an error code otherwise (-Exxxx). */ int (*checkentry)(const struct xt_tgchk_param *); + /* Called to validate hooks based on the target configuration. */ + int (*check_hooks)(const struct xt_tgchk_param *); + /* Called when entry of this type deleted. */ void (*destroy)(const struct xt_tgdtor_param *); #ifdef CONFIG_NETFILTER_XTABLES_COMPAT @@ -279,8 +285,10 @@ bool xt_find_jump_offset(const unsigned int *offsets, int xt_check_proc_name(const char *name, unsigned int size); +int xt_check_hooks_match(struct xt_mtchk_param *par); int xt_check_match(struct xt_mtchk_param *, unsigned int size, u16 proto, bool inv_proto); +int xt_check_hooks_target(struct xt_tgchk_param *par); int xt_check_target(struct xt_tgchk_param *, unsigned int size, u16 proto, bool inv_proto); -- cgit v1.2.3 From b62eb8dcf2c47d4d676a434efbd57c4f776f7829 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Wed, 6 May 2026 12:07:14 +0200 Subject: netfilter: x_tables: allocate hook ops while under mutex arp/ip(6)t_register_table() add the table to the per-netns list via xt_register_table() before allocating the per-netns hook ops copy via kmemdup_array(). This leaves a window where the table is visible in the list with ops=NULL. If the pernet exit happens runs concurrently the pre_exit callback finds the table via xt_find_table() and passes the NULL ops pointer to nf_unregister_net_hooks(), causing a NULL dereference: general protection fault in nf_unregister_net_hooks+0xbc/0x150 RIP: nf_unregister_net_hooks (net/netfilter/core.c:613) Call Trace: ipt_unregister_table_pre_exit iptable_mangle_net_pre_exit ops_pre_exit_list cleanup_net Fix by moving the ops allocation into the xtables core so the table is never in the list without valid ops. Also ensure the table is no longer processing packets before its torn down on error unwind. nf_register_net_hooks might have published at least one hook; call synchronize_rcu() if there was an error. audit log register message gets deferred until all operations have passed, this avoids need to emit another ureg message in case of error unwinding. Based on earlier patch by Tristan Madani. Fixes: f9006acc8dfe5 ("netfilter: arp_tables: pass table pointer via nf_hook_ops") Fixes: ee177a54413a ("netfilter: ip6_tables: pass table pointer via nf_hook_ops") Fixes: ae689334225f ("netfilter: ip_tables: pass table pointer via nf_hook_ops") Link: https://lore.kernel.org/netfilter-devel/20260429175613.1459342-1-tristmd@gmail.com/ Signed-off-by: Tristan Madani Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/x_tables.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/netfilter') diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index a81b46af5118..cb4b694dd9e4 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -305,6 +305,7 @@ 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); -- cgit v1.2.3 From 527d6931473b75d90e38942aae6537d1a527f1fd Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Wed, 6 May 2026 12:07:15 +0200 Subject: netfilter: x_tables: add and use xt_unregister_table_pre_exit Remove the copypasted variants of _pre_exit and add one single function in the xtables core. ebtables is not compatible with x_tables and therefore unchanged. This is a preparation patch to reduce noise in the followup bug fixes. Reviewed-by: Tristan Madani Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/x_tables.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/netfilter') diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index cb4b694dd9e4..74486714ae20 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -309,6 +309,7 @@ struct xt_table *xt_register_table(struct net *net, 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_info *xt_replace_table(struct xt_table *table, unsigned int num_counters, -- cgit v1.2.3 From b4597d5fd7d2f8cebfffd40dffb5e003cc78964c Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Wed, 6 May 2026 12:07:17 +0200 Subject: netfilter: x_tables: add and use xtables_unregister_table_exit Previous change added xtables_unregister_table_pre_exit to detach the table from the packetpath and to unlink it from the active table list. In case of rmmod, userspace that is doing set/getsockopt for this table will not be able to re-instantiate the table: 1. The larval table has been removed already 2. existing instantiated table is no longer on the xt pernet table list. This adds the second stage helper: unlink the table from the dying list, free the hook ops (if any) and do the audit notification. It replaces xt_unregister_table(). Fixes: fdacd57c79b7 ("netfilter: x_tables: never register tables by default") Reported-by: Tristan Madani Reviewed-by: Tristan Madani Closes: https://lore.kernel.org/netfilter-devel/20260429175613.1459342-1-tristmd@gmail.com/ Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/x_tables.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/netfilter') diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 74486714ae20..5a1c5c336fa4 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -308,8 +308,8 @@ struct xt_table *xt_register_table(struct net *net, 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, -- cgit v1.2.3