[PATCH 3.16 101/114] net: fix infoleak in llc

From: Ben Hutchings
Date: Mon Jun 13 2016 - 14:58:31 EST


3.16.36-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Kangjie Lu <kangjielu@xxxxxxxxx>

commit b8670c09f37bdf2847cc44f36511a53afc6161fd upstream.

The stack object âinfoâ has a total size of 12 bytes. Its last byte
is padding which is not initialized and leaked via âput_cmsgâ.

Signed-off-by: Kangjie Lu <kjlu@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
net/llc/af_llc.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -626,6 +626,7 @@ static void llc_cmsg_rcv(struct msghdr *
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);