Merge tag 'audit-pr-20200601' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit
Pull audit updates from Paul Moore:
"Summary of the significant patches:
- Record information about binds/unbinds to the audit multicast
socket. This helps identify which processes have/had access to the
information in the audit stream.
- Cleanup and add some additional information to the netfilter
configuration events collected by audit.
- Fix some of the audit error handling code so we don't leak network
namespace references"
* tag 'audit-pr-20200601' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
audit: add subj creds to NETFILTER_CFG record to
audit: Replace zero-length array with flexible-array
audit: make symbol 'audit_nfcfgs' static
netfilter: add audit table unregister actions
audit: tidy and extend netfilter_cfg x_tables
audit: log audit netlink multicast bind and unbind
audit: fix a net reference leak in audit_list_rules_send()
audit: fix a net reference leak in audit_send_reply()
diff --git a/include/linux/audit.h b/include/linux/audit.h
index f9ceae5..3fcd9ee 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -19,7 +19,7 @@
struct audit_sig_info {
uid_t uid;
pid_t pid;
- char ctx[0];
+ char ctx[];
};
struct audit_buffer;
@@ -94,6 +94,12 @@ struct audit_ntp_data {
struct audit_ntp_data {};
#endif
+enum audit_nfcfgop {
+ AUDIT_XT_OP_REGISTER,
+ AUDIT_XT_OP_REPLACE,
+ AUDIT_XT_OP_UNREGISTER,
+};
+
extern int is_audit_feature_set(int which);
extern int __init audit_register_class(int class, unsigned *list);
@@ -379,6 +385,8 @@ extern void __audit_log_kern_module(char *name);
extern void __audit_fanotify(unsigned int response);
extern void __audit_tk_injoffset(struct timespec64 offset);
extern void __audit_ntp_log(const struct audit_ntp_data *ad);
+extern void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,
+ enum audit_nfcfgop op);
static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp)
{
@@ -514,6 +522,14 @@ static inline void audit_ntp_log(const struct audit_ntp_data *ad)
__audit_ntp_log(ad);
}
+static inline void audit_log_nfcfg(const char *name, u8 af,
+ unsigned int nentries,
+ enum audit_nfcfgop op)
+{
+ if (audit_enabled)
+ __audit_log_nfcfg(name, af, nentries, op);
+}
+
extern int audit_n_rules;
extern int audit_signals;
#else /* CONFIG_AUDITSYSCALL */
@@ -646,6 +662,12 @@ static inline void audit_ntp_log(const struct audit_ntp_data *ad)
static inline void audit_ptrace(struct task_struct *t)
{ }
+
+static inline void audit_log_nfcfg(const char *name, u8 af,
+ unsigned int nentries,
+ enum audit_nfcfgop op)
+{ }
+
#define audit_n_rules 0
#define audit_signals 0
#endif /* CONFIG_AUDITSYSCALL */
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index a534d71..9b6a973 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -117,6 +117,7 @@
#define AUDIT_TIME_INJOFFSET 1332 /* Timekeeping offset injected */
#define AUDIT_TIME_ADJNTPVAL 1333 /* NTP value adjustment */
#define AUDIT_BPF 1334 /* BPF subsystem */
+#define AUDIT_EVENT_LISTENER 1335 /* Task joined multicast read socket */
#define AUDIT_AVC 1400 /* SE Linux avc denial or grant */
#define AUDIT_SELINUX_ERR 1401 /* Internal SE Linux Errors */
diff --git a/kernel/audit.c b/kernel/audit.c
index 87f31bf..8c201f4 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -880,7 +880,7 @@ static int kauditd_thread(void *dummy)
return 0;
}
-int audit_send_list(void *_dest)
+int audit_send_list_thread(void *_dest)
{
struct audit_netlink_list *dest = _dest;
struct sk_buff *skb;
@@ -924,19 +924,30 @@ struct sk_buff *audit_make_reply(int seq, int type, int done,
return NULL;
}
+static void audit_free_reply(struct audit_reply *reply)
+{
+ if (!reply)
+ return;
+
+ if (reply->skb)
+ kfree_skb(reply->skb);
+ if (reply->net)
+ put_net(reply->net);
+ kfree(reply);
+}
+
static int audit_send_reply_thread(void *arg)
{
struct audit_reply *reply = (struct audit_reply *)arg;
- struct sock *sk = audit_get_sk(reply->net);
audit_ctl_lock();
audit_ctl_unlock();
/* Ignore failure. It'll only happen if the sender goes away,
because our timeout is set to infinite. */
- netlink_unicast(sk, reply->skb, reply->portid, 0);
- put_net(reply->net);
- kfree(reply);
+ netlink_unicast(audit_get_sk(reply->net), reply->skb, reply->portid, 0);
+ reply->skb = NULL;
+ audit_free_reply(reply);
return 0;
}
@@ -950,35 +961,32 @@ static int audit_send_reply_thread(void *arg)
* @payload: payload data
* @size: payload size
*
- * Allocates an skb, builds the netlink message, and sends it to the port id.
- * No failure notifications.
+ * Allocates a skb, builds the netlink message, and sends it to the port id.
*/
static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
int multi, const void *payload, int size)
{
- struct net *net = sock_net(NETLINK_CB(request_skb).sk);
- struct sk_buff *skb;
struct task_struct *tsk;
- struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
- GFP_KERNEL);
+ struct audit_reply *reply;
+ reply = kzalloc(sizeof(*reply), GFP_KERNEL);
if (!reply)
return;
- skb = audit_make_reply(seq, type, done, multi, payload, size);
- if (!skb)
- goto out;
-
- reply->net = get_net(net);
+ reply->skb = audit_make_reply(seq, type, done, multi, payload, size);
+ if (!reply->skb)
+ goto err;
+ reply->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
reply->portid = NETLINK_CB(request_skb).portid;
- reply->skb = skb;
tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
- if (!IS_ERR(tsk))
- return;
- kfree_skb(skb);
-out:
- kfree(reply);
+ if (IS_ERR(tsk))
+ goto err;
+
+ return;
+
+err:
+ audit_free_reply(reply);
}
/*
@@ -1525,20 +1533,60 @@ static void audit_receive(struct sk_buff *skb)
audit_ctl_unlock();
}
-/* Run custom bind function on netlink socket group connect or bind requests. */
-static int audit_bind(struct net *net, int group)
+/* Log information about who is connecting to the audit multicast socket */
+static void audit_log_multicast(int group, const char *op, int err)
{
- if (!capable(CAP_AUDIT_READ))
- return -EPERM;
+ const struct cred *cred;
+ struct tty_struct *tty;
+ char comm[sizeof(current->comm)];
+ struct audit_buffer *ab;
- return 0;
+ if (!audit_enabled)
+ return;
+
+ ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_EVENT_LISTENER);
+ if (!ab)
+ return;
+
+ cred = current_cred();
+ tty = audit_get_tty();
+ audit_log_format(ab, "pid=%u uid=%u auid=%u tty=%s ses=%u",
+ task_pid_nr(current),
+ from_kuid(&init_user_ns, cred->uid),
+ from_kuid(&init_user_ns, audit_get_loginuid(current)),
+ tty ? tty_name(tty) : "(none)",
+ audit_get_sessionid(current));
+ audit_put_tty(tty);
+ audit_log_task_context(ab); /* subj= */
+ audit_log_format(ab, " comm=");
+ audit_log_untrustedstring(ab, get_task_comm(comm, current));
+ audit_log_d_path_exe(ab, current->mm); /* exe= */
+ audit_log_format(ab, " nl-mcgrp=%d op=%s res=%d", group, op, !err);
+ audit_log_end(ab);
+}
+
+/* Run custom bind function on netlink socket group connect or bind requests. */
+static int audit_multicast_bind(struct net *net, int group)
+{
+ int err = 0;
+
+ if (!capable(CAP_AUDIT_READ))
+ err = -EPERM;
+ audit_log_multicast(group, "connect", err);
+ return err;
+}
+
+static void audit_multicast_unbind(struct net *net, int group)
+{
+ audit_log_multicast(group, "disconnect", 0);
}
static int __net_init audit_net_init(struct net *net)
{
struct netlink_kernel_cfg cfg = {
.input = audit_receive,
- .bind = audit_bind,
+ .bind = audit_multicast_bind,
+ .unbind = audit_multicast_unbind,
.flags = NL_CFG_F_NONROOT_RECV,
.groups = AUDIT_NLGRP_MAX,
};
diff --git a/kernel/audit.h b/kernel/audit.h
index 2eed4d2..f0233dc 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -229,7 +229,7 @@ struct audit_netlink_list {
struct sk_buff_head q;
};
-int audit_send_list(void *_dest);
+int audit_send_list_thread(void *_dest);
extern int selinux_audit_rule_update(void);
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 026e34d..a10e299 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1161,11 +1161,8 @@ int audit_rule_change(int type, int seq, void *data, size_t datasz)
*/
int audit_list_rules_send(struct sk_buff *request_skb, int seq)
{
- u32 portid = NETLINK_CB(request_skb).portid;
- struct net *net = sock_net(NETLINK_CB(request_skb).sk);
struct task_struct *tsk;
struct audit_netlink_list *dest;
- int err = 0;
/* We can't just spew out the rules here because we might fill
* the available socket buffer space and deadlock waiting for
@@ -1173,25 +1170,26 @@ int audit_list_rules_send(struct sk_buff *request_skb, int seq)
* happen if we're actually running in the context of auditctl
* trying to _send_ the stuff */
- dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
+ dest = kmalloc(sizeof(*dest), GFP_KERNEL);
if (!dest)
return -ENOMEM;
- dest->net = get_net(net);
- dest->portid = portid;
+ dest->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
+ dest->portid = NETLINK_CB(request_skb).portid;
skb_queue_head_init(&dest->q);
mutex_lock(&audit_filter_mutex);
audit_list_rules(seq, &dest->q);
mutex_unlock(&audit_filter_mutex);
- tsk = kthread_run(audit_send_list, dest, "audit_send_list");
+ tsk = kthread_run(audit_send_list_thread, dest, "audit_send_list");
if (IS_ERR(tsk)) {
skb_queue_purge(&dest->q);
+ put_net(dest->net);
kfree(dest);
- err = PTR_ERR(tsk);
+ return PTR_ERR(tsk);
}
- return err;
+ return 0;
}
int audit_comparator(u32 left, u32 op, u32 right)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 814406a..468a233 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -130,6 +130,17 @@ struct audit_tree_refs {
struct audit_chunk *c[31];
};
+struct audit_nfcfgop_tab {
+ enum audit_nfcfgop op;
+ const char *s;
+};
+
+static const struct audit_nfcfgop_tab audit_nfcfgs[] = {
+ { AUDIT_XT_OP_REGISTER, "register" },
+ { AUDIT_XT_OP_REPLACE, "replace" },
+ { AUDIT_XT_OP_UNREGISTER, "unregister" },
+};
+
static int audit_match_perm(struct audit_context *ctx, int mask)
{
unsigned n;
@@ -2542,6 +2553,26 @@ void __audit_ntp_log(const struct audit_ntp_data *ad)
audit_log_ntp_val(ad, "adjust", AUDIT_NTP_ADJUST);
}
+void __audit_log_nfcfg(const char *name, u8 af, unsigned int nentries,
+ enum audit_nfcfgop op)
+{
+ struct audit_buffer *ab;
+ char comm[sizeof(current->comm)];
+
+ ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_NETFILTER_CFG);
+ if (!ab)
+ return;
+ audit_log_format(ab, "table=%s family=%u entries=%u op=%s",
+ name, af, nentries, audit_nfcfgs[op].s);
+
+ audit_log_format(ab, " pid=%u", task_pid_nr(current));
+ audit_log_task_context(ab); /* subj= */
+ audit_log_format(ab, " comm=");
+ audit_log_untrustedstring(ab, get_task_comm(comm, current));
+ audit_log_end(ab);
+}
+EXPORT_SYMBOL_GPL(__audit_log_nfcfg);
+
static void audit_log_task(struct audit_buffer *ab)
{
kuid_t auid, uid;
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 7e86928..c83ffe91 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1046,14 +1046,8 @@ static int do_replace_finish(struct net *net, struct ebt_replace *repl,
vfree(table);
vfree(counterstmp);
-#ifdef CONFIG_AUDIT
- if (audit_enabled) {
- audit_log(audit_context(), GFP_KERNEL,
- AUDIT_NETFILTER_CFG,
- "table=%s family=%u entries=%u",
- repl->name, AF_BRIDGE, repl->nentries);
- }
-#endif
+ audit_log_nfcfg(repl->name, AF_BRIDGE, repl->nentries,
+ AUDIT_XT_OP_REPLACE);
return ret;
free_unlock:
@@ -1128,6 +1122,8 @@ static void __ebt_unregister_table(struct net *net, struct ebt_table *table)
mutex_lock(&ebt_mutex);
list_del(&table->list);
mutex_unlock(&ebt_mutex);
+ audit_log_nfcfg(table->name, AF_BRIDGE, table->private->nentries,
+ AUDIT_XT_OP_UNREGISTER);
EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
ebt_cleanup_entry, net, NULL);
if (table->private->nentries)
@@ -1221,6 +1217,8 @@ int ebt_register_table(struct net *net, const struct ebt_table *input_table,
*res = NULL;
}
+ audit_log_nfcfg(repl->name, AF_BRIDGE, repl->nentries,
+ AUDIT_XT_OP_REGISTER);
return ret;
free_unlock:
mutex_unlock(&ebt_mutex);
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index cd2b034..99a468b 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -1408,15 +1408,9 @@ xt_replace_table(struct xt_table *table,
}
}
-#ifdef CONFIG_AUDIT
- if (audit_enabled) {
- audit_log(audit_context(), GFP_KERNEL,
- AUDIT_NETFILTER_CFG,
- "table=%s family=%u entries=%u",
- table->name, table->af, private->number);
- }
-#endif
-
+ audit_log_nfcfg(table->name, table->af, private->number,
+ !private->number ? AUDIT_XT_OP_REGISTER :
+ AUDIT_XT_OP_REPLACE);
return private;
}
EXPORT_SYMBOL_GPL(xt_replace_table);
@@ -1478,6 +1472,8 @@ void *xt_unregister_table(struct xt_table *table)
private = table->private;
list_del(&table->list);
mutex_unlock(&xt[table->af].mutex);
+ audit_log_nfcfg(table->name, table->af, private->number,
+ AUDIT_XT_OP_UNREGISTER);
kfree(table);
return private;