[PATCH 3.19.y-ckt 36/40] net: fix infoleak in llc

[Kamal Mostafa]

3.19.8-ckt22 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Kangjie Lu <kangjielu at gmail.com>

[ Upstream commit b8670c09f37bdf2847cc44f36511a53afc6161fd ]

The stack object “info” has a total size of 12 bytes. Its last byte
is padding which is not initialized and leaked via “put_cmsg”.

Signed-off-by: Kangjie Lu <kjlu at gatech.edu>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/llc/af_llc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index 2c0b83c..05e5c76 100644
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -626,6 +626,7 @@ static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb)
 	if (llc->cmsg_flags & LLC_CMSG_PKTINFO) {
 		struct llc_pktinfo info;
 
+		memset(&info, 0, sizeof(info));
 		info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex;
 		llc_pdu_decode_dsap(skb, &info.lpi_sap);
 		llc_pdu_decode_da(skb, info.lpi_mac);
-- 
2.7.4