[106/118] netrom: fix info leak via msg_name in nr_recvmsg()

Ben Hutchings
2013-05-10T14:48:56Z

From: Mathias Krause <minipli@googlemail.com>

[ Upstream commits 3ce5efad47b62c57a4f5c54248347085a750ce0e and
c802d759623acbd6e1ee9fbdabae89159a513913 ]

In case msg_name is set the sockaddr info gets filled out, as
requested, but the code fails to initialize the padding bytes of
struct sockaddr_ax25 inserted by the compiler for alignment. Also
the sax25_ndigis member does not get assigned, leaking four more
bytes.

Both issues lead to the fact that the code will leak uninitialized
kernel stack bytes in net/socket.c.

Fix both issues by initializing the memory with memset(0).

Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
net/netrom/af_netrom.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -1178,6 +1178,7 @@ static int nr_recvmsg(struct kiocb *iocb
}

if (sax != NULL) {
+ memset(sax, 0, sizeof(sax));
sax->sax25_family = AF_NETROM;
skb_copy_from_linear_data_offset(skb, 7, sax->sax25_call.ax25_call,
AX25_ADDR_LEN);