[Lucid CVE-2012-6546 2/2] atm: fix info leak in getsockopt(SO_ATMPVC)

[Luis Henriques]

From: Mathias Krause <minipli at googlemail.com>

CVE-2012-6546

BugLink: http://bugs.launchpad.net/bugs/1156759

The ATM code fails to initialize the two padding bytes of struct
sockaddr_atmpvc inserted for alignment. Add an explicit memset(0)
before filling the structure to avoid the info leak.

Signed-off-by: Mathias Krause <minipli at googlemail.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(back ported from commit e862f1a9b7df4e8196ebec45ac62295138aa3fc2)

Signed-off-by: Luis Henriques <luis.henriques at canonical.com>

Conflicts:
	net/atm/common.c
---
 net/atm/common.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/atm/common.c b/net/atm/common.c
index 950bd16..0baf05e 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -749,6 +749,7 @@ int vcc_getsockopt(struct socket *sock, int level, int optname,
 				if (!vcc->dev ||
 				    !test_bit(ATM_VF_ADDR,&vcc->flags))
 					return -ENOTCONN;
+				memset(&pvc, 0, sizeof(pvc));
 				pvc.sap_family = AF_ATMPVC;
 				pvc.sap_addr.itf = vcc->dev->number;
 				pvc.sap_addr.vpi = vcc->vpi;
-- 
1.8.1.2