1 files changed, 23 insertions, 2 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index b29e6dc44650..0834958f1dc4 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -682,7 +682,7 @@ static void *__bpf_copy_key(void __user *ukey, u64 key_size)
 }
 
 /* last field in 'union bpf_attr' used by this command */
-#define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value
+#define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
 
 static int map_lookup_elem(union bpf_attr *attr)
 {
@@ -698,6 +698,9 @@ static int map_lookup_elem(union bpf_attr *attr)
         if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
                 return -EINVAL;
 
+        if (attr->flags & ~BPF_F_LOCK)
+                return -EINVAL;
+
         f = fdget(ufd);
         map = __bpf_map_get(f);
         if (IS_ERR(map))
@@ -708,6 +711,12 @@ static int map_lookup_elem(union bpf_attr *attr)
                 goto err_put;
         }
 
+        if ((attr->flags & BPF_F_LOCK) &&
+            !map_value_has_spin_lock(map)) {
+                err = -EINVAL;
+                goto err_put;
+        }
+
         key = __bpf_copy_key(ukey, map->key_size);
         if (IS_ERR(key)) {
                 err = PTR_ERR(key);
@@ -758,7 +767,13 @@ static int map_lookup_elem(union bpf_attr *attr)
                         err = -ENOENT;
                 } else {
                         err = 0;
-                        copy_map_value(map, value, ptr);
+                        if (attr->flags & BPF_F_LOCK)
+                                /* lock 'ptr' and copy everything but lock */
+                                copy_map_value_locked(map, value, ptr, true);
+                        else
+                                copy_map_value(map, value, ptr);
+                        /* mask lock, since value wasn't zero inited */
+                        check_and_init_map_lock(map, value);
                 }
                 rcu_read_unlock();
         }
@@ -818,6 +833,12 @@ static int map_update_elem(union bpf_attr *attr)
                 goto err_put;
         }
 
+        if ((attr->flags & BPF_F_LOCK) &&
+            !map_value_has_spin_lock(map)) {
+                err = -EINVAL;
+                goto err_put;
+        }
+
         key = __bpf_copy_key(ukey, map->key_size);
         if (IS_ERR(key)) {
                 err = PTR_ERR(key);