[PATCH 6/6 RFC] netfilter: add audit netns ID

Seemingly duplicate NETFILTER_CFG records are not actually exact duplicates that are caused by netfilter table initialization in different network namespaces from the same syscall. To differentiate the NETFILTER_CFG records, the network namespace ID (proc inode) was added to the record to make this source evident. Here is a sample event with accompanied records: time->Sun May 14 22:40:26 2017 type=PROCTITLE msg=audit(1494816026.072:248): proctitle=2F7362696E2F6D6F6470726F6265002D71002D2D0065627461626C655F6E6174 type=KERN_MODULE msg=audit(1494816026.072:248): name="ebtable_nat" type=SYSCALL msg=audit(1494816026.072:248): arch=c000003e syscall=313 success=yes exit=0 a0=0 a1=55c4648d4106 a2=0 a3=0 items=0 ppid=84 pid=431 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="modprobe" exe="/usr/bin/kmod" subj=system_u:system_r:insmod_t:s0 key="mod-load" type=NETFILTER_CFG msg=audit(1494816026.072:248): op=register net=324 family=7 table=nat entries=0 type=NETFILTER_CFG msg=audit(1494816026.072:248): op=register net=121 family=7 table=nat entries=0 and unaccompanied cases: type=UNKNOWN[1331] msg=audit(1494815998.178:167): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=system_u:system_r:iptables_t:s0 pid=598 comm="ip6tables-resto" exe="/usr/sbin/xtables-multi" op=replace net=121 family=10 table=filter entries=4 See: https://github.com/linux-audit/audit-kernel/issues/25 Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; --- include/linux/netfilter/x_tables.h | 1 + net/bridge/netfilter/ebtables.c | 13 +++++++++---- net/ipv4/netfilter/arp_tables.c | 2 +- net/ipv4/netfilter/ip_tables.c | 2 +- net/ipv6/netfilter/ip6_tables.c | 2 +- net/netfilter/x_tables.c | 10 +++++++--- 6 files changed, 20 insertions(+), 10 deletions(-) diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index be378cf..6be4a04 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -308,6 +308,7 @@ struct xt_table *xt_register_table(struct net *net, struct xt_table_info *xt_replace_table(struct xt_table *table, unsigned int num_counters, struct xt_table_info *newinfo, + struct net *net, int *error); struct xt_match *xt_find_match(u8 af, const char *name, u8 revision); diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index 59b63a8..0f77b2a 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -27,6 +27,7 @@ #include <linux/smp.h> #include <linux/cpumask.h> #include <linux/audit.h> +#define PROC_DYNAMIC_FIRST 0xF0000000U #include <net/sock.h> /* needed for logical [in,out]-dev filtering */ #include "../br_private.h" @@ -1075,7 +1076,8 @@ static int do_replace_finish(struct net *net, struct ebt_replace *repl, ab = audit_log_start(current->audit_context, GFP_KERNEL, AUDIT_NETFILTER_CFG); if (ab) { - audit_log_format(ab, "op=replace family=%u table=%s entries=%u", + audit_log_format(ab, "op=replace net=%u family=%u table=%s entries=%u", + net->ns.inum - PROC_DYNAMIC_FIRST, AF_BRIDGE, repl->name, repl->nentries); audit_log_end(ab); @@ -1085,7 +1087,8 @@ static int do_replace_finish(struct net *net, struct ebt_replace *repl, AUDIT_NETFILTER_CFGSOLO); if (ab) { audit_log_task(ab); - audit_log_format(ab, " op=replace family=%u table=%s entries=%u", + audit_log_format(ab, " op=replace net=%u family=%u table=%s entries=%u", + net->ns.inum - PROC_DYNAMIC_FIRST, AF_BRIDGE, repl->name, repl->nentries); audit_log_end(ab); @@ -1259,7 +1262,8 @@ struct ebt_table * ebt_register_table(struct net *net, ab = audit_log_start(current->audit_context, GFP_KERNEL, AUDIT_NETFILTER_CFG); if (ab) { - audit_log_format(ab, "op=register family=%u table=%s entries=%u", + audit_log_format(ab, "op=register net=%u family=%u table=%s entries=%u", + net->ns.inum - PROC_DYNAMIC_FIRST, AF_BRIDGE, repl->name, repl->nentries); audit_log_end(ab); @@ -1269,7 +1273,8 @@ struct ebt_table * ebt_register_table(struct net *net, AUDIT_NETFILTER_CFGSOLO); if (ab) { audit_log_task(ab); - audit_log_format(ab, " op=register family=%u table=%s entries=%u", + audit_log_format(ab, " op=register net=%u family=%u table=%s entries=%u", + net->ns.inum - PROC_DYNAMIC_FIRST, AF_BRIDGE, repl->name, repl->nentries); audit_log_end(ab); diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index 6241a81..4933a5a 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -904,7 +904,7 @@ static int __do_replace(struct net *net, const char *name, goto put_module; } - oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); + oldinfo = xt_replace_table(t, num_counters, newinfo, net, &ret); if (!oldinfo) goto put_module; diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index 384b857..c638607 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -1066,7 +1066,7 @@ static int get_info(struct net *net, void __user *user, goto put_module; } - oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); + oldinfo = xt_replace_table(t, num_counters, newinfo, net, &ret); if (!oldinfo) goto put_module; diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index 1e15c54..87ef83b 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1096,7 +1096,7 @@ static int get_info(struct net *net, void __user *user, goto put_module; } - oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); + oldinfo = xt_replace_table(t, num_counters, newinfo, net, &ret); if (!oldinfo) goto put_module; diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index 395ebd3..35533f1 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -26,6 +26,7 @@ #include <linux/mm.h> #include <linux/slab.h> #include <linux/audit.h> +#define PROC_DYNAMIC_FIRST 0xF0000000U #include <linux/user_namespace.h> #include <net/net_namespace.h> @@ -1151,6 +1152,7 @@ static int xt_jumpstack_alloc(struct xt_table_info *i) struct xt_table_info *xt_replace_table(struct xt_table *table, unsigned int num_counters, struct xt_table_info *newinfo, + struct net *net, int *error) { struct xt_table_info *private; @@ -1199,8 +1201,9 @@ struct xt_table_info *xt_replace_table(struct xt_table *table, ab = audit_log_start(current->audit_context, GFP_KERNEL, AUDIT_NETFILTER_CFG); if (ab) { - audit_log_format(ab, "op=%s family=%u table=%s entries=%u", + audit_log_format(ab, "op=%s net=%u family=%u table=%s entries=%u", private->number ? "replace" : "register", + net->ns.inum - PROC_DYNAMIC_FIRST, table->af, table->name, private->number); audit_log_end(ab); @@ -1210,7 +1213,8 @@ struct xt_table_info *xt_replace_table(struct xt_table *table, AUDIT_NETFILTER_CFGSOLO); if (ab) { audit_log_task(ab); - audit_log_format(ab, " op=replace family=%u table=%s entries=%u", + audit_log_format(ab, " op=replace net=%u family=%u table=%s entries=%u", + net->ns.inum - PROC_DYNAMIC_FIRST, table->af, table->name, private->number); audit_log_end(ab); @@ -1251,7 +1255,7 @@ struct xt_table *xt_register_table(struct net *net, /* Simplifies replace_table code. */ table->private = bootstrap; - if (!xt_replace_table(table, 0, newinfo, &ret)) + if (!xt_replace_table(table, 0, newinfo, net, &ret)) goto unlock; private = table->private; -- 1.7.1