Blob Blame History Raw
From: Richard Guy Briggs <rgb@redhat.com>
Date: Thu, 4 Jun 2020 09:20:49 -0400
Subject: audit: log nftables configuration change events
Patch-mainline: v5.9-rc1
Git-commit: 8e6cf365e1d5c70e275a77a3c5ad7e3dc685474c
References: bsc#1176447

iptables, ip6tables, arptables and ebtables table registration,
replacement and unregistration configuration events are logged for the
native (legacy) iptables setsockopt api, but not for the
nftables netlink api which is used by the nft-variant of iptables in
addition to nftables itself.

Add calls to log the configuration actions in the nftables netlink api.

This uses the same NETFILTER_CFG record format but overloads the table
field.

  type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.878:162) : table=?:0;?:0 family=unspecified entries=2 op=nft_register_gen pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
  ...
  type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.878:162) : table=firewalld:1;?:0 family=inet entries=0 op=nft_register_table pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
  ...
  type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;filter_FORWARD:85 family=inet entries=8 op=nft_register_chain pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
  ...
  type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;filter_FORWARD:85 family=inet entries=101 op=nft_register_rule pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
  ...
  type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;__set0:87 family=inet entries=87 op=nft_register_setelem pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld
  ...
  type=NETFILTER_CFG msg=audit(2020-05-28 17:46:41.911:163) : table=firewalld:1;__set0:87 family=inet entries=0 op=nft_register_set pid=396 subj=system_u:system_r:firewalld_t:s0 comm=firewalld

For further information please see issue
https://github.com/linux-audit/audit-kernel/issues/124

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 include/linux/audit.h         |   18 +++++++
 kernel/auditsc.c              |   24 ++++++++-
 net/netfilter/nf_tables_api.c |  103 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 142 insertions(+), 3 deletions(-)

--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -13,6 +13,7 @@
 #include <linux/ptrace.h>
 #include <linux/namei.h>  /* LOOKUP_* */
 #include <uapi/linux/audit.h>
+#include <uapi/linux/netfilter/nf_tables.h>
 
 #define AUDIT_INO_UNSET ((unsigned long)-1)
 #define AUDIT_DEV_UNSET ((dev_t)-1)
@@ -99,6 +100,23 @@ enum audit_nfcfgop {
 	AUDIT_XT_OP_REGISTER,
 	AUDIT_XT_OP_REPLACE,
 	AUDIT_XT_OP_UNREGISTER,
+	AUDIT_NFT_OP_TABLE_REGISTER,
+	AUDIT_NFT_OP_TABLE_UNREGISTER,
+	AUDIT_NFT_OP_CHAIN_REGISTER,
+	AUDIT_NFT_OP_CHAIN_UNREGISTER,
+	AUDIT_NFT_OP_RULE_REGISTER,
+	AUDIT_NFT_OP_RULE_UNREGISTER,
+	AUDIT_NFT_OP_SET_REGISTER,
+	AUDIT_NFT_OP_SET_UNREGISTER,
+	AUDIT_NFT_OP_SETELEM_REGISTER,
+	AUDIT_NFT_OP_SETELEM_UNREGISTER,
+	AUDIT_NFT_OP_GEN_REGISTER,
+	AUDIT_NFT_OP_OBJ_REGISTER,
+	AUDIT_NFT_OP_OBJ_UNREGISTER,
+	AUDIT_NFT_OP_OBJ_RESET,
+	AUDIT_NFT_OP_FLOWTABLE_REGISTER,
+	AUDIT_NFT_OP_FLOWTABLE_UNREGISTER,
+	AUDIT_NFT_OP_INVALID,
 };
 
 extern int is_audit_feature_set(int which);
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -75,6 +75,7 @@
 #include <linux/uaccess.h>
 #include <linux/fsnotify_backend.h>
 #include <uapi/linux/limits.h>
+#include <uapi/linux/netfilter/nf_tables.h>
 
 #include "audit.h"
 
@@ -136,9 +137,26 @@ struct audit_nfcfgop_tab {
 };
 
 static const struct audit_nfcfgop_tab audit_nfcfgs[] = {
-	{ AUDIT_XT_OP_REGISTER,		"register"	},
-	{ AUDIT_XT_OP_REPLACE,		"replace"	},
-	{ AUDIT_XT_OP_UNREGISTER,	"unregister"	},
+	{ AUDIT_XT_OP_REGISTER,			"xt_register"		   },
+	{ AUDIT_XT_OP_REPLACE,			"xt_replace"		   },
+	{ AUDIT_XT_OP_UNREGISTER,		"xt_unregister"		   },
+	{ AUDIT_NFT_OP_TABLE_REGISTER,		"nft_register_table"	   },
+	{ AUDIT_NFT_OP_TABLE_UNREGISTER,	"nft_unregister_table"	   },
+	{ AUDIT_NFT_OP_CHAIN_REGISTER,		"nft_register_chain"	   },
+	{ AUDIT_NFT_OP_CHAIN_UNREGISTER,	"nft_unregister_chain"	   },
+	{ AUDIT_NFT_OP_RULE_REGISTER,		"nft_register_rule"	   },
+	{ AUDIT_NFT_OP_RULE_UNREGISTER,		"nft_unregister_rule"	   },
+	{ AUDIT_NFT_OP_SET_REGISTER,		"nft_register_set"	   },
+	{ AUDIT_NFT_OP_SET_UNREGISTER,		"nft_unregister_set"	   },
+	{ AUDIT_NFT_OP_SETELEM_REGISTER,	"nft_register_setelem"	   },
+	{ AUDIT_NFT_OP_SETELEM_UNREGISTER,	"nft_unregister_setelem"   },
+	{ AUDIT_NFT_OP_GEN_REGISTER,		"nft_register_gen"	   },
+	{ AUDIT_NFT_OP_OBJ_REGISTER,		"nft_register_obj"	   },
+	{ AUDIT_NFT_OP_OBJ_UNREGISTER,		"nft_unregister_obj"	   },
+	{ AUDIT_NFT_OP_OBJ_RESET,		"nft_reset_obj"		   },
+	{ AUDIT_NFT_OP_FLOWTABLE_REGISTER,	"nft_register_flowtable"   },
+	{ AUDIT_NFT_OP_FLOWTABLE_UNREGISTER,	"nft_unregister_flowtable" },
+	{ AUDIT_NFT_OP_INVALID,			"nft_invalid"		   },
 };
 
 static int audit_match_perm(struct audit_context *ctx, int mask)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -12,6 +12,7 @@
 #include <linux/netlink.h>
 #include <linux/vmalloc.h>
 #include <linux/rhashtable.h>
+#include <linux/audit.h>
 #include <linux/netfilter.h>
 #include <linux/netfilter/nfnetlink.h>
 #include <linux/netfilter/nf_tables.h>
@@ -681,6 +682,16 @@ static void nf_tables_table_notify(const
 {
 	struct sk_buff *skb;
 	int err;
+	char *buf = kasprintf(GFP_KERNEL, "%s:%llu;?:0",
+			      ctx->table->name, ctx->table->handle);
+
+	audit_log_nfcfg(buf,
+			ctx->family,
+			ctx->table->use,
+			event == NFT_MSG_NEWTABLE ?
+				AUDIT_NFT_OP_TABLE_REGISTER :
+				AUDIT_NFT_OP_TABLE_UNREGISTER);
+	kfree(buf);
 
 	if (!ctx->report &&
 	    !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
@@ -1415,6 +1426,17 @@ static void nf_tables_chain_notify(const
 {
 	struct sk_buff *skb;
 	int err;
+	char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu",
+			      ctx->table->name, ctx->table->handle,
+			      ctx->chain->name, ctx->chain->handle);
+
+	audit_log_nfcfg(buf,
+			ctx->family,
+			ctx->chain->use,
+			event == NFT_MSG_NEWCHAIN ?
+				AUDIT_NFT_OP_CHAIN_REGISTER :
+				AUDIT_NFT_OP_CHAIN_UNREGISTER);
+	kfree(buf);
 
 	if (!ctx->report &&
 	    !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
@@ -2680,6 +2702,17 @@ static void nf_tables_rule_notify(const
 {
 	struct sk_buff *skb;
 	int err;
+	char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu",
+			      ctx->table->name, ctx->table->handle,
+			      ctx->chain->name, ctx->chain->handle);
+
+	audit_log_nfcfg(buf,
+			ctx->family,
+			rule->handle,
+			event == NFT_MSG_NEWRULE ?
+				AUDIT_NFT_OP_RULE_REGISTER :
+				AUDIT_NFT_OP_RULE_UNREGISTER);
+	kfree(buf);
 
 	if (!ctx->report &&
 	    !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
@@ -3682,6 +3715,17 @@ static void nf_tables_set_notify(const s
 	struct sk_buff *skb;
 	u32 portid = ctx->portid;
 	int err;
+	char *buf = kasprintf(gfp_flags, "%s:%llu;%s:%llu",
+			      ctx->table->name, ctx->table->handle,
+			      set->name, set->handle);
+
+	audit_log_nfcfg(buf,
+			ctx->family,
+			set->field_count,
+			event == NFT_MSG_NEWSET ?
+				AUDIT_NFT_OP_SET_REGISTER :
+				AUDIT_NFT_OP_SET_UNREGISTER);
+	kfree(buf);
 
 	if (!ctx->report &&
 	    !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
@@ -4798,6 +4842,17 @@ static void nf_tables_setelem_notify(con
 	u32 portid = ctx->portid;
 	struct sk_buff *skb;
 	int err;
+	char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu",
+			      ctx->table->name, ctx->table->handle,
+			      set->name, set->handle);
+
+	audit_log_nfcfg(buf,
+			ctx->family,
+			set->handle,
+			event == NFT_MSG_NEWSETELEM ?
+				AUDIT_NFT_OP_SETELEM_REGISTER :
+				AUDIT_NFT_OP_SETELEM_UNREGISTER);
+	kfree(buf);
 
 	if (!ctx->report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES))
 		return;
@@ -5879,6 +5934,19 @@ static int nf_tables_dump_obj(struct sk_
 			    obj->ops->type->type != filter->type)
 				goto cont;
 
+			if (reset) {
+				char *buf = kasprintf(GFP_KERNEL,
+						      "%s:%llu;?:0",
+						      table->name,
+						      table->handle);
+
+				audit_log_nfcfg(buf,
+						family,
+						obj->handle,
+						AUDIT_NFT_OP_OBJ_RESET);
+				kfree(buf);
+			}
+
 			if (nf_tables_fill_obj_info(skb, net, NETLINK_CB(cb->skb).portid,
 						    cb->nlh->nlmsg_seq,
 						    NFT_MSG_NEWOBJ,
@@ -5989,6 +6057,17 @@ static int nf_tables_getobj(struct net *
 	if (NFNL_MSG_TYPE(nlh->nlmsg_type) == NFT_MSG_GETOBJ_RESET)
 		reset = true;
 
+	if (reset) {
+		char *buf = kasprintf(GFP_KERNEL, "%s:%llu;?:0",
+				      table->name, table->handle);
+
+		audit_log_nfcfg(buf,
+				family,
+				obj->handle,
+				AUDIT_NFT_OP_OBJ_RESET);
+		kfree(buf);
+	}
+
 	err = nf_tables_fill_obj_info(skb2, net, NETLINK_CB(skb).portid,
 				      nlh->nlmsg_seq, NFT_MSG_NEWOBJ, 0,
 				      family, table, obj, reset);
@@ -6064,6 +6143,16 @@ void nft_obj_notify(struct net *net, con
 {
 	struct sk_buff *skb;
 	int err;
+	char *buf = kasprintf(GFP_KERNEL, "%s:%llu;?:0",
+			      table->name, table->handle);
+
+	audit_log_nfcfg(buf,
+			family,
+			obj->handle,
+			event == NFT_MSG_NEWOBJ ?
+				AUDIT_NFT_OP_OBJ_REGISTER :
+				AUDIT_NFT_OP_OBJ_UNREGISTER);
+	kfree(buf);
 
 	if (!report &&
 	    !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES))
@@ -6860,6 +6949,17 @@ static void nf_tables_flowtable_notify(s
 {
 	struct sk_buff *skb;
 	int err;
+	char *buf = kasprintf(GFP_KERNEL, "%s:%llu;%s:%llu",
+			      flowtable->table->name, flowtable->table->handle,
+			      flowtable->name, flowtable->handle);
+
+	audit_log_nfcfg(buf,
+			ctx->family,
+			flowtable->hooknum,
+			event == NFT_MSG_NEWFLOWTABLE ?
+				AUDIT_NFT_OP_FLOWTABLE_REGISTER :
+				AUDIT_NFT_OP_FLOWTABLE_UNREGISTER);
+	kfree(buf);
 
 	if (ctx->report &&
 	    !nfnetlink_has_listeners(ctx->net, NFNLGRP_NFTABLES))
@@ -6981,6 +7081,9 @@ static void nf_tables_gen_notify(struct
 	struct sk_buff *skb2;
 	int err;
 
+	audit_log_nfcfg("?:0;?:0", 0, net->nft.base_seq,
+			AUDIT_NFT_OP_GEN_REGISTER);
+
 	if (nlmsg_report(nlh) &&
 	    !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES))
 		return;