[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>

2 files changed, 13 insertions, 6 deletions

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index a24f38510719..c394b413f651 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1997,9 +1997,14 @@ 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;
+                return;
 
         switch(type) {
         case AUDIT_MAC_IPSEC_ADDSA:
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index d55436d00e86..256745321611 100644
--- a/net/xfrm/xfrm_user.c
+++ b/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;