3 files changed, 82 insertions, 30 deletions

diff --git a/include/net/flow.h b/include/net/flow.h
index ddf5f3ca1720..3b44d72b27d3 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -97,7 +97,7 @@ struct flowi {
 #define FLOW_DIR_FWD    2
 
 struct sock;
-typedef void (*flow_resolve_t)(struct flowi *key, u16 family, u8 dir,
+typedef int (*flow_resolve_t)(struct flowi *key, u16 family, u8 dir,
                                void **objp, atomic_t **obj_refp);
 
 extern void *flow_cache_lookup(struct flowi *key, u16 family, u8 dir,
diff --git a/net/core/flow.c b/net/core/flow.c
index f23e7e386543..b16d31ae5e54 100644
--- a/net/core/flow.c
+++ b/net/core/flow.c
@@ -85,6 +85,14 @@ static void flow_cache_new_hashrnd(unsigned long arg)
         add_timer(&flow_hash_rnd_timer);
 }
 
+static void flow_entry_kill(int cpu, struct flow_cache_entry *fle)
+{
+        if (fle->object)
+                atomic_dec(fle->object_ref);
+        kmem_cache_free(flow_cachep, fle);
+        flow_count(cpu)--;
+}
+
 static void __flow_cache_shrink(int cpu, int shrink_to)
 {
         struct flow_cache_entry *fle, **flp;
@@ -100,10 +108,7 @@ static void __flow_cache_shrink(int cpu, int shrink_to)
                 }
                 while ((fle = *flp) != NULL) {
                         *flp = fle->next;
-                        if (fle->object)
-                                atomic_dec(fle->object_ref);
-                        kmem_cache_free(flow_cachep, fle);
-                        flow_count(cpu)--;
+                        flow_entry_kill(cpu, fle);
                 }
         }
 }
@@ -220,24 +225,33 @@ void *flow_cache_lookup(struct flowi *key, u16 family, u8 dir,
 
 nocache:
         {
+                int err;
                 void *obj;
                 atomic_t *obj_ref;
 
-                resolver(key, family, dir, &obj, &obj_ref);
+                err = resolver(key, family, dir, &obj, &obj_ref);
 
                 if (fle) {
-                        fle->genid = atomic_read(&flow_cache_genid);
-
-                        if (fle->object)
-                                atomic_dec(fle->object_ref);
-
-                        fle->object = obj;
-                        fle->object_ref = obj_ref;
-                        if (obj)
-                                atomic_inc(fle->object_ref);
+                        if (err) {
+                                /* Force security policy check on next lookup */
+                                *head = fle->next;
+                                flow_entry_kill(cpu, fle);
+                        } else {
+                                fle->genid = atomic_read(&flow_cache_genid);
+
+                                if (fle->object)
+                                        atomic_dec(fle->object_ref);
+
+                                fle->object = obj;
+                                fle->object_ref = obj_ref;
+                                if (obj)
+                                        atomic_inc(fle->object_ref);
+                        }
                 }
                 local_bh_enable();
 
+                if (err)
+                        obj = ERR_PTR(err);
                 return obj;
         }
 }
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 2a7861661f14..fffdd34f3baf 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -883,30 +883,32 @@ out:
 }
 EXPORT_SYMBOL(xfrm_policy_walk);
 
-/* Find policy to apply to this flow. */
-
+/*
+ * Find policy to apply to this flow.
+ *
+ * Returns 0 if policy found, else an -errno.
+ */
 static int xfrm_policy_match(struct xfrm_policy *pol, struct flowi *fl,
                              u8 type, u16 family, int dir)
 {
         struct xfrm_selector *sel = &pol->selector;
-        int match;
+        int match, ret = -ESRCH;
 
         if (pol->family != family ||
             pol->type != type)
-                return 0;
+                return ret;
 
         match = xfrm_selector_match(sel, fl, family);
-        if (match) {
-                if (!security_xfrm_policy_lookup(pol, fl->secid, dir))
-                        return 1;
-        }
+        if (match)
+                ret = security_xfrm_policy_lookup(pol, fl->secid, dir);
 
-        return 0;
+        return ret;
 }
 
 static struct xfrm_policy *xfrm_policy_lookup_bytype(u8 type, struct flowi *fl,
                                                      u16 family, u8 dir)
 {
+        int err;
         struct xfrm_policy *pol, *ret;
         xfrm_address_t *daddr, *saddr;
         struct hlist_node *entry;
@@ -922,7 +924,15 @@ static struct xfrm_policy *xfrm_policy_lookup_bytype(u8 type, struct flowi *fl,
         chain = policy_hash_direct(daddr, saddr, family, dir);
         ret = NULL;
         hlist_for_each_entry(pol, entry, chain, bydst) {
-                if (xfrm_policy_match(pol, fl, type, family, dir)) {
+                err = xfrm_policy_match(pol, fl, type, family, dir);
+                if (err) {
+                        if (err == -ESRCH)
+                                continue;
+                        else {
+                                ret = ERR_PTR(err);
+                                goto fail;
+                        }
+                } else {
                         ret = pol;
                         priority = ret->priority;
                         break;
@@ -930,36 +940,53 @@ static struct xfrm_policy *xfrm_policy_lookup_bytype(u8 type, struct flowi *fl,
         }
         chain = &xfrm_policy_inexact[dir];
         hlist_for_each_entry(pol, entry, chain, bydst) {
-                if (xfrm_policy_match(pol, fl, type, family, dir) &&
-                    pol->priority < priority) {
+                err = xfrm_policy_match(pol, fl, type, family, dir);
+                if (err) {
+                        if (err == -ESRCH)
+                                continue;
+                        else {
+                                ret = ERR_PTR(err);
+                                goto fail;
+                        }
+                } else if (pol->priority < priority) {
                         ret = pol;
                         break;
                 }
         }
         if (ret)
                 xfrm_pol_hold(ret);
+fail:
         read_unlock_bh(&xfrm_policy_lock);
 
         return ret;
 }
 
-static void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
+static int xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir,
                                void **objp, atomic_t **obj_refp)
 {
         struct xfrm_policy *pol;
+        int err = 0;
 
 #ifdef CONFIG_XFRM_SUB_POLICY
         pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_SUB, fl, family, dir);
-        if (pol)
+        if (IS_ERR(pol)) {
+                err = PTR_ERR(pol);
+                pol = NULL;
+        }
+        if (pol || err)
                 goto end;
 #endif
         pol = xfrm_policy_lookup_bytype(XFRM_POLICY_TYPE_MAIN, fl, family, dir);
-
+        if (IS_ERR(pol)) {
+                err = PTR_ERR(pol);
+                pol = NULL;
+        }
 #ifdef CONFIG_XFRM_SUB_POLICY
 end:
 #endif
         if ((*objp = (void *) pol) != NULL)
                 *obj_refp = &pol->refcnt;
+        return err;
 }
 
 static inline int policy_to_flow_dir(int dir)
@@ -1297,6 +1324,8 @@ restart:
 
                 policy = flow_cache_lookup(fl, dst_orig->ops->family,
                                            dir, xfrm_policy_lookup);
+                if (IS_ERR(policy))
+                        return PTR_ERR(policy);
         }
 
         if (!policy)
@@ -1343,6 +1372,10 @@ restart:
                                                             fl, family,
                                                             XFRM_POLICY_OUT);
                         if (pols[1]) {
+                                if (IS_ERR(pols[1])) {
+                                        err = PTR_ERR(pols[1]);
+                                        goto error;
+                                }
                                 if (pols[1]->action == XFRM_POLICY_BLOCK) {
                                         err = -EPERM;
                                         goto error;
@@ -1581,6 +1614,9 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
                 pol = flow_cache_lookup(&fl, family, fl_dir,
                                         xfrm_policy_lookup);
 
+        if (IS_ERR(pol))
+                return 0;
+
         if (!pol) {
                 if (skb->sp && secpath_has_nontransport(skb->sp, 0, &xerr_idx)) {
                         xfrm_secpath_reject(xerr_idx, skb, &fl);
@@ -1599,6 +1635,8 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
                                                     &fl, family,
                                                     XFRM_POLICY_IN);
                 if (pols[1]) {
+                        if (IS_ERR(pols[1]))
+                                return 0;
                         pols[1]->curlft.use_time = (unsigned long)xtime.tv_sec;
                         npols ++;
                 }