bpf: check for reserved flag bits in array and stack maps

4ast · davem330 · commit 823707b68d6e · 2016-03-08T15:28:31.000-05:00
Suggested-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
@@ -53,7 +53,7 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr)
 
 	/* check sanity of attributes */
 	if (attr->max_entries == 0 || attr->key_size != 4 ||
-	    attr->value_size == 0)
+	    attr->value_size == 0 || attr->map_flags)
 		return ERR_PTR(-EINVAL);
 
 	if (attr->value_size >= 1 << (KMALLOC_SHIFT_MAX - 1))
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
@@ -35,6 +35,9 @@ static struct bpf_map *stack_map_alloc(union bpf_attr *attr)
 	if (!capable(CAP_SYS_ADMIN))
 		return ERR_PTR(-EPERM);
 
+	if (attr->map_flags)
+		return ERR_PTR(-EINVAL);
+
 	/* check sanity of attributes */
 	if (attr->max_entries == 0 || attr->key_size != 4 ||
 	    value_size < 8 || value_size % 8 ||
