Re: [PATCH] net: Zeroing the structure ethtool_wolinfo in ethtool_get_wol()
From: Dan Carpenter <hidden>
Date: 2019-10-26 14:26:24
Also in:
bpf, lkml
On Sat, Oct 26, 2019 at 03:54:16PM +0800, zhanglin wrote:
quoted hunk ↗ jump to hunk
memset() the structure ethtool_wolinfo that has padded bytes but the padded bytes have not been zeroed out. Signed-off-by: zhanglin <redacted> --- net/core/ethtool.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)diff --git a/net/core/ethtool.c b/net/core/ethtool.c index aeabc48..563a845 100644 --- a/net/core/ethtool.c +++ b/net/core/ethtool.c@@ -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;
How did you detect that they weren't initialized? Is this a KASAN thing? Most of the time GCC will zero out the padding bytes when you have an initializer like this, but sometimes it just makes the intialization a series of assignments which leaves the holes uninitialized. I wish I knew the rules so that I could check for it in Smatch. Or even better, I wish that there were an option to always zero the holes in this situation... regards, dan carpenter