Code: static int dcbnl_getperm_hwaddr(struct net_device *netdev, struct nlmsghdr *nlh,
				u32 seq, struct nlattr **tb, struct sk_buff *skb)
{
	u8 perm_addr[MAX_ADDR_LEN];

 	if (!netdev->dcbnl_ops->getpermhwaddr)
 		return -EOPNOTSUPP;
 
 	netdev->dcbnl_ops->getpermhwaddr(netdev, perm_addr);
 
 	return nla_put(skb, DCB_ATTR_PERM_HWADDR, sizeof(perm_addr), perm_addr);
}

Vulnerability Type: +Info 
CWE ID: CWE-399
Summary: net/dcb/dcbnl.c in the Linux kernel before 3.8.4 does not initialize certain structures, which allows local users to obtain sensitive information from kernel stack memory via a crafted application.
Commit Message: dcbnl: fix various netlink info leaks

The dcb netlink interface leaks stack memory in various places:
* perm_addr[] buffer is only filled at max with 12 of the 32 bytes but
  copied completely,
* no in-kernel driver fills all fields of an IEEE 802.1Qaz subcommand,
  so we're leaking up to 58 bytes for ieee_ets structs, up to 136 bytes
  for ieee_pfc structs, etc.,
* the same is true for CEE -- no in-kernel driver fills the whole
  struct,

Prevent all of the above stack info leaks by properly initializing the
buffers/structures involved.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>