[PATCH 3.12 72/76] net: fix a kernel infoleak in x25 module

[Jiri Slaby]

From: Kangjie Lu <kangjielu@xxxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

[ Upstream commit 79e48650320e6fba48369fccf13fd045315b19b8 ]

Stack object "dte_facilities" is allocated in x25_rx_call_request(),
which is supposed to be initialized in x25_negotiate_facilities.
However, 5 fields (8 bytes in total) are not initialized. This
object is then copied to userland via copy_to_user, thus infoleak
occurs.

Signed-off-by: Kangjie Lu <kjlu@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 net/x25/x25_facilities.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/x25/x25_facilities.c b/net/x25/x25_facilities.c
index b8253250d723..c42bf2b8ec4f 100644
--- a/net/x25/x25_facilities.c
+++ b/net/x25/x25_facilities.c
@@ -275,6 +275,7 @@ int x25_negotiate_facilities(struct sk_buff *skb, struct sock *sk,
 
 	memset(&theirs, 0, sizeof(theirs));
 	memcpy(new, ours, sizeof(*new));
+	memset(dte, 0, sizeof(*dte));
 
 	len = x25_parse_facilities(skb, &theirs, dte, &x25->vc_facil_mask);
 	if (len < 0)
-- 
2.8.2