X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=kernel%2Faudit.c;h=9c8e5f732c4c79472883e1094e22ca469e43cdb4;hb=cd9bd10c59e3c1446680514fd3097c5b00d3712d;hp=16205dd29843b7713c490ce59b6bb3ea062ebfbe;hpb=3669558bdf354cd352be955ef2764cde6a9bf5ec;p=platform%2Fkernel%2Flinux-rpi.git

diff --git a/kernel/audit.c b/kernel/audit.c
index 16205dd..9c8e5f7 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -487,15 +487,19 @@ static void auditd_conn_free(struct rcu_head *rcu)
  * @pid: auditd PID
  * @portid: auditd netlink portid
  * @net: auditd network namespace pointer
+ * @skb: the netlink command from the audit daemon
+ * @ack: netlink ack flag, cleared if ack'd here
  *
  * Description:
  * This function will obtain and drop network namespace references as
  * necessary.  Returns zero on success, negative values on failure.
  */
-static int auditd_set(struct pid *pid, u32 portid, struct net *net)
+static int auditd_set(struct pid *pid, u32 portid, struct net *net,
+		      struct sk_buff *skb, bool *ack)
 {
 	unsigned long flags;
 	struct auditd_connection *ac_old, *ac_new;
+	struct nlmsghdr *nlh;
 
 	if (!pid || !net)
 		return -EINVAL;
@@ -507,6 +511,13 @@ static int auditd_set(struct pid *pid, u32 portid, struct net *net)
 	ac_new->portid = portid;
 	ac_new->net = get_net(net);
 
+	/* send the ack now to avoid a race with the queue backlog */
+	if (*ack) {
+		nlh = nlmsg_hdr(skb);
+		netlink_ack(skb, nlh, 0, NULL);
+		*ack = false;
+	}
+
 	spin_lock_irqsave(&auditd_conn_lock, flags);
 	ac_old = rcu_dereference_protected(auditd_conn,
 					   lockdep_is_held(&auditd_conn_lock));
@@ -1200,7 +1211,8 @@ static int audit_replace(struct pid *pid)
 	return auditd_send_unicast_skb(skb);
 }
 
-static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+			     bool *ack)
 {
 	u32			seq;
 	void			*data;
@@ -1293,7 +1305,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 				/* register a new auditd connection */
 				err = auditd_set(req_pid,
 						 NETLINK_CB(skb).portid,
-						 sock_net(NETLINK_CB(skb).sk));
+						 sock_net(NETLINK_CB(skb).sk),
+						 skb, ack);
 				if (audit_enabled != AUDIT_OFF)
 					audit_log_config_change("audit_pid",
 								new_pid,
@@ -1538,9 +1551,10 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
  * Parse the provided skb and deal with any messages that may be present,
  * malformed skbs are discarded.
  */
-static void audit_receive(struct sk_buff  *skb)
+static void audit_receive(struct sk_buff *skb)
 {
 	struct nlmsghdr *nlh;
+	bool ack;
 	/*
 	 * len MUST be signed for nlmsg_next to be able to dec it below 0
 	 * if the nlmsg_len was not aligned
@@ -1553,9 +1567,12 @@ static void audit_receive(struct sk_buff  *skb)
 
 	audit_ctl_lock();
 	while (nlmsg_ok(nlh, len)) {
-		err = audit_receive_msg(skb, nlh);
-		/* if err or if this message says it wants a response */
-		if (err || (nlh->nlmsg_flags & NLM_F_ACK))
+		ack = nlh->nlmsg_flags & NLM_F_ACK;
+		err = audit_receive_msg(skb, nlh, &ack);
+
+		/* send an ack if the user asked for one and audit_receive_msg
+		 * didn't already do it, or if there was an error. */
+		if (ack || err)
 			netlink_ack(skb, nlh, err, NULL);
 
 		nlh = nlmsg_next(nlh, &len);