Re: [Cocci] [PATCH] net: Zeroing the structure ethtool_wolinfo in ethtool_get_wol()

On 26.10.19 21:40, Joe Perches wrote:

On Sat, 2019-10-26 at 15:54 +0800, zhanglin wrote:

quoted

memset() the structure ethtool_wolinfo that has padded bytes
but the padded bytes have not been zeroed out.

[]

quoted

diff --git a/net/core/ethtool.c b/net/core/ethtool.c

[]

quoted

@@ -1471,11 +1471,13 @@ static int ethtool_reset(struct net_device *dev, char __user *useraddr)
 
 static int ethtool_get_wol(struct net_device *dev, char __user *useraddr)
 {
-	struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL };
+	struct ethtool_wolinfo wol;
 
 	if (!dev->ethtool_ops->get_wol)
 		return -EOPNOTSUPP;
 
+	memset(&wol, 0, sizeof(struct ethtool_wolinfo));
+	wol.cmd = ETHTOOL_GWOL;
 	dev->ethtool_ops->get_wol(dev, &wol);
 
 	if (copy_to_user(useraddr, &wol, sizeof(wol)))

It seems likely there are more of these.

Is there any way for coccinelle to find them?

Just curios: is static struct initialization (on stack) something that
should be avoided ? I've been under the impression that static
initialization allows thinner code and gives the compiler better chance
for optimizations.


--mtx

---
Enrico Weigelt, metux IT consult
Free software and Linux embedded engineering
info@metux.net -- +49-151-27565287