net/switchdev: use struct_size over open coded arithmetic

Replace zero-length array with flexible-array member and make use
of the struct_size() helper in kmalloc(). For example:

struct switchdev_deferred_item {
    ...
    unsigned long data[];
};

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi (CGEL ZTE) <chi.minghao@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c
index b62565278faccfb7f96228a19304a9ec6c161655..12e6b4146bfb4d7786d4f08ef0f0ed0c68432690 100644 (file)
--- a/net/switchdev/switchdev.c
+++ b/net/switchdev/switchdev.c
@@ -85,7 +85,7 @@ static int switchdev_deferred_enqueue(struct net_device *dev,
 {
        struct switchdev_deferred_item *dfitem;
 
-       dfitem = kmalloc(sizeof(*dfitem) + data_len, GFP_ATOMIC);
+       dfitem = kmalloc(struct_size(dfitem, data, data_len), GFP_ATOMIC);
        if (!dfitem)
                return -ENOMEM;
        dfitem->dev = dev;