Merge branch 'bpf'

Alexei Starovoitov says:

====================
bpf: fix two bugs

Michael Holzheu caught two issues (in bpf syscall and in the test).
Fix them. Details in corresponding patches.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

kernel/bpf/syscall.c

@@ -150,7 +150,7 @@ static int map_lookup_elem(union bpf_attr *attr)
 	int ufd = attr->map_fd;
 	struct fd f = fdget(ufd);
 	struct bpf_map *map;
-	void *key, *value;
+	void *key, *value, *ptr;
 	int err;
 
 	if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
@@ -169,20 +169,29 @@ static int map_lookup_elem(union bpf_attr *attr)
 	if (copy_from_user(key, ukey, map->key_size) != 0)
 		goto free_key;
 
-	err = -ENOENT;
-	rcu_read_lock();
-	value = map->ops->map_lookup_elem(map, key);
+	err = -ENOMEM;
+	value = kmalloc(map->value_size, GFP_USER);
 	if (!value)
-		goto err_unlock;
+		goto free_key;
+
+	rcu_read_lock();
+	ptr = map->ops->map_lookup_elem(map, key);
+	if (ptr)
+		memcpy(value, ptr, map->value_size);
+	rcu_read_unlock();
+
+	err = -ENOENT;
+	if (!ptr)
+		goto free_value;
 
 	err = -EFAULT;
 	if (copy_to_user(uvalue, value, map->value_size) != 0)
-		goto err_unlock;
+		goto free_value;
 
 	err = 0;
 
-err_unlock:
-	rcu_read_unlock();
+free_value:
+	kfree(value);
 free_key:
 	kfree(key);
 err_put:

samples/bpf/test_maps.c

@@ -69,9 +69,9 @@ static void test_hashmap_sanity(int i, void *data)
 
 	/* iterate over two elements */
 	assert(bpf_get_next_key(map_fd, &key, &next_key) == 0 &&
-	       next_key == 2);
+	       (next_key == 1 || next_key == 2));
 	assert(bpf_get_next_key(map_fd, &next_key, &next_key) == 0 &&
-	       next_key == 1);
+	       (next_key == 1 || next_key == 2));
 	assert(bpf_get_next_key(map_fd, &next_key, &next_key) == -1 &&
 	       errno == ENOENT);