[Lucid CVE-2013-2634] dcbnl: fix various netlink info leaks

Luis Henriques luis.henriques at canonical.com
Fri Apr 12 13:16:59 UTC 2013

From: Mathias Krause <minipli at googlemail.com>


BugLink: http://bugs.launchpad.net/bugs/1158965

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

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

Signed-off-by: Mathias Krause <minipli at googlemail.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(back ported from commit 29cd8ae0e1a39e239a3a7b67da1986add1199fc0)

Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
 net/dcb/dcbnl.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index ac1205d..813fe4b 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -307,6 +307,7 @@ static int dcbnl_getperm_hwaddr(struct net_device *netdev, struct nlattr **tb,
 	dcb->dcb_family = AF_UNSPEC;
 	dcb->cmd = DCB_CMD_GPERM_HWADDR;
+	memset(perm_addr, 0, sizeof(perm_addr));
 	netdev->dcbnl_ops->getpermhwaddr(netdev, perm_addr);
 	ret = nla_put(dcbnl_skb, DCB_ATTR_PERM_HWADDR, sizeof(perm_addr),

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