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authorLinus Torvalds <torvalds@linux-foundation.org>2020-06-02 17:13:37 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-02 17:13:37 -0700
commit9d99b1647fa56805c1cfef2d81ee7b9855359b62 (patch)
treec269a202d1ac16c5ed7e12d8d173eb136f3a385f /kernel/audit.c
parent91681e8480af21dcab2c0d91bb1b7851cbc83d81 (diff)
parent9d44a121c5a79bc8a9d67c058456bd52a83c79e7 (diff)
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()
Diffstat (limited to 'kernel/audit.c')
-rw-r--r--kernel/audit.c100
1 files changed, 74 insertions, 26 deletions
diff --git a/kernel/audit.c b/kernel/audit.c
index 87f31bf1f0a0..8c201f414226 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -880,7 +880,7 @@ main_queue:
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 @@ out_kfree_skb:
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();
}
+/* Log information about who is connecting to the audit multicast socket */
+static void audit_log_multicast(int group, const char *op, int err)
+{
+ const struct cred *cred;
+ struct tty_struct *tty;
+ char comm[sizeof(current->comm)];
+ struct audit_buffer *ab;
+
+ 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_bind(struct net *net, int group)
+static int audit_multicast_bind(struct net *net, int group)
{
+ int err = 0;
+
if (!capable(CAP_AUDIT_READ))
- return -EPERM;
+ err = -EPERM;
+ audit_log_multicast(group, "connect", err);
+ return err;
+}
- return 0;
+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,
};

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