[XFRM]: Fix OOPSes in xfrm_audit_log().

Make sure that this function is called correctly, and
add BUG() checking to ensure the arguments are sane.

Based upon a patch by Joy Latten.
Signed-off-by: David S. Miller <davem@davemloft.net>

net/key/af_key.c

@@ -2297,16 +2297,17 @@ static int pfkey_spddelete(struct sock *sk, struct sk_buff *skb, struct sadb_msg
 				   &sel, tmp.security, 1);
 	security_xfrm_policy_free(&tmp);
 
-	xfrm_audit_log(audit_get_loginuid(current->audit_context), 0,
-		       AUDIT_MAC_IPSEC_DELSPD, (xp) ? 1 : 0, xp, NULL);
-
 	if (xp == NULL)
 		return -ENOENT;
 
-	err = 0;
+	err = security_xfrm_policy_delete(xp);
 
-	if ((err = security_xfrm_policy_delete(xp)))
+	xfrm_audit_log(audit_get_loginuid(current->audit_context), 0,
+		       AUDIT_MAC_IPSEC_DELSPD, err ? 0 : 1, xp, NULL);
+
+	if (err)
 		goto out;
+
 	c.seq = hdr->sadb_msg_seq;
 	c.pid = hdr->sadb_msg_pid;
 	c.event = XFRM_MSG_DELPOLICY;

net/xfrm/xfrm_policy.c

@@ -1997,6 +1997,11 @@ void xfrm_audit_log(uid_t auid, u32 sid, int type, int result,
 	if (audit_enabled == 0)
 		return;
 
+	BUG_ON((type == AUDIT_MAC_IPSEC_ADDSA ||
+		type == AUDIT_MAC_IPSEC_DELSA) && !x);
+	BUG_ON((type == AUDIT_MAC_IPSEC_ADDSPD ||
+		type == AUDIT_MAC_IPSEC_DELSPD) && !xp);
+
 	audit_buf = audit_log_start(current->audit_context, GFP_ATOMIC, type);
 	if (audit_buf == NULL)
 		return;

net/xfrm/xfrm_user.c

@@ -1273,10 +1273,6 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh,
 		xp = xfrm_policy_bysel_ctx(type, p->dir, &p->sel, tmp.security, delete);
 		security_xfrm_policy_free(&tmp);
 	}
-	if (delete)
-		xfrm_audit_log(NETLINK_CB(skb).loginuid, NETLINK_CB(skb).sid,
-			       AUDIT_MAC_IPSEC_DELSPD, (xp) ? 1 : 0, xp, NULL);
-
 	if (xp == NULL)
 		return -ENOENT;
 
@@ -1292,8 +1288,14 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh,
 					      MSG_DONTWAIT);
 		}
 	} else {
-		if ((err = security_xfrm_policy_delete(xp)) != 0)
+		err = security_xfrm_policy_delete(xp);
+
+		xfrm_audit_log(NETLINK_CB(skb).loginuid, NETLINK_CB(skb).sid,
+			       AUDIT_MAC_IPSEC_DELSPD, err ? 0 : 1, xp, NULL);
+
+		if (err != 0)
 			goto out;
+
 		c.data.byid = p->index;
 		c.event = nlh->nlmsg_type;
 		c.seq = nlh->nlmsg_seq;