[IPSEC]: Policy list disorder

The recent hashing introduced an off-by-one bug in policy list insertion.
Instead of adding after the last entry with a lesser or equal priority,
we're adding after the successor of that entry.

This patch fixes this and also adds a warning if we detect a duplicate
entry in the policy list.  This should never happen due to this if clause.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index bebd40e5a62e161f03f630adac629d8baa014d99..b7e537fe2d7542d95335e7a2a1fde2172a5ba0b8 100644 (file)
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -650,19 +650,18 @@ int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
        struct xfrm_policy *pol;
        struct xfrm_policy *delpol;
        struct hlist_head *chain;
-       struct hlist_node *entry, *newpos, *last;
+       struct hlist_node *entry, *newpos;
        struct dst_entry *gc_list;
 
        write_lock_bh(&xfrm_policy_lock);
        chain = policy_hash_bysel(&policy->selector, policy->family, dir);
        delpol = NULL;
        newpos = NULL;
-       last = NULL;
        hlist_for_each_entry(pol, entry, chain, bydst) {
-               if (!delpol &&
-                   pol->type == policy->type &&
+               if (pol->type == policy->type &&
                    !selector_cmp(&pol->selector, &policy->selector) &&
-                   xfrm_sec_ctx_match(pol->security, policy->security)) {
+                   xfrm_sec_ctx_match(pol->security, policy->security) &&
+                   !WARN_ON(delpol)) {
                        if (excl) {
                                write_unlock_bh(&xfrm_policy_lock);
                                return -EEXIST;
@@ -671,17 +670,12 @@ int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
                        if (policy->priority > pol->priority)
                                continue;
                } else if (policy->priority >= pol->priority) {
-                       last = &pol->bydst;
+                       newpos = &pol->bydst;
                        continue;
                }
-               if (!newpos)
-                       newpos = &pol->bydst;
                if (delpol)
                        break;
-               last = &pol->bydst;
        }
-       if (!newpos)
-               newpos = last;
        if (newpos)
                hlist_add_after(newpos, &policy->bydst);
        else