1 files changed, 13 insertions, 1 deletions

diff --git a/net/core/flow.c b/net/core/flow.c
index 1033725be40b..3937b1b68d5b 100644
--- a/net/core/flow.c
+++ b/net/core/flow.c
@@ -92,8 +92,11 @@ static void flow_cache_gc_task(struct work_struct *work)
         list_splice_tail_init(&xfrm->flow_cache_gc_list, &gc_list);
         spin_unlock_bh(&xfrm->flow_cache_gc_lock);
 
-        list_for_each_entry_safe(fce, n, &gc_list, u.gc_list)
+        list_for_each_entry_safe(fce, n, &gc_list, u.gc_list) {
                 flow_entry_kill(fce, xfrm);
+                atomic_dec(&xfrm->flow_cache_gc_count);
+                WARN_ON(atomic_read(&xfrm->flow_cache_gc_count) < 0);
+        }
 }
 
 static void flow_cache_queue_garbage(struct flow_cache_percpu *fcp,
@@ -101,6 +104,7 @@ static void flow_cache_queue_garbage(struct flow_cache_percpu *fcp,
                                      struct netns_xfrm *xfrm)
 {
         if (deleted) {
+                atomic_add(deleted, &xfrm->flow_cache_gc_count);
                 fcp->hash_count -= deleted;
                 spin_lock_bh(&xfrm->flow_cache_gc_lock);
                 list_splice_tail(gc_list, &xfrm->flow_cache_gc_list);
@@ -232,6 +236,13 @@ flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir,
                 if (fcp->hash_count > fc->high_watermark)
                         flow_cache_shrink(fc, fcp);
 
+                if (fcp->hash_count > 2 * fc->high_watermark ||
+                    atomic_read(&net->xfrm.flow_cache_gc_count) > fc->high_watermark) {
+                        atomic_inc(&net->xfrm.flow_cache_genid);
+                        flo = ERR_PTR(-ENOBUFS);
+                        goto ret_object;
+                }
+
                 fle = kmem_cache_alloc(flow_cachep, GFP_ATOMIC);
                 if (fle) {
                         fle->net = net;
@@ -446,6 +457,7 @@ int flow_cache_init(struct net *net)
         INIT_WORK(&net->xfrm.flow_cache_gc_work, flow_cache_gc_task);
         INIT_WORK(&net->xfrm.flow_cache_flush_work, flow_cache_flush_task);
         mutex_init(&net->xfrm.flow_flush_sem);
+        atomic_set(&net->xfrm.flow_cache_gc_count, 0);
 
         fc->hash_shift = 10;
         fc->low_watermark = 2 * flow_cache_hash_size(fc);