1 files changed, 26 insertions, 2 deletions

diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index a15bc636cc98..6c63c2222ea8 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -226,9 +226,33 @@ int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
         return 0;
 }
 
-static int stack_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
+static int stack_map_get_next_key(struct bpf_map *map, void *key,
+                                  void *next_key)
 {
-        return -EINVAL;
+        struct bpf_stack_map *smap = container_of(map,
+                                                  struct bpf_stack_map, map);
+        u32 id;
+
+        WARN_ON_ONCE(!rcu_read_lock_held());
+
+        if (!key) {
+                id = 0;
+        } else {
+                id = *(u32 *)key;
+                if (id >= smap->n_buckets || !smap->buckets[id])
+                        id = 0;
+                else
+                        id++;
+        }
+
+        while (id < smap->n_buckets && !smap->buckets[id])
+                id++;
+
+        if (id >= smap->n_buckets)
+                return -ENOENT;
+
+        *(u32 *)next_key = id;
+        return 0;
 }
 
 static int stack_map_update_elem(struct bpf_map *map, void *key, void *value,