Convert infiniband uverbs to struct_size

The flows were hidden from the C compiler; expose them as a zero-length
array to allow struct_size to work.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

2 files changed, 3 insertions, 6 deletions

diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 3179a95c6f5e..3e90b6a1d9d2 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -3559,8 +3559,8 @@ int ib_uverbs_ex_create_flow(struct ib_uverbs_file *file,
                 goto err_uobj;
         }
 
-        flow_attr = kzalloc(sizeof(*flow_attr) + cmd.flow_attr.num_of_specs *
-                            sizeof(union ib_flow_spec), GFP_KERNEL);
+        flow_attr = kzalloc(struct_size(flow_attr, flows,
+                                cmd.flow_attr.num_of_specs), GFP_KERNEL);
         if (!flow_attr) {
                 err = -ENOMEM;
                 goto err_put;
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 2043e1a8f851..4c6241bc2039 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2093,10 +2093,7 @@ struct ib_flow_attr {
         u32          flags;
         u8           num_of_specs;
         u8           port;
-        /* Following are the optional layers according to user request
-         * struct ib_flow_spec_xxx
-         * struct ib_flow_spec_yyy
-         */
+        union ib_flow_spec flows[];
 };
 
 struct ib_flow {