[104/126] netrom: fix info leak via msg_name in nr_recvmsg()

Steven Rostedt
2013-05-07T04:25:56Z

[-- Attachment #1: 0104-netrom-fix-info-leak-via-msg_name-in-nr_recvmsg.patch --]
[-- Type: text/plain, Size: 1348 bytes --]

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

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

From: Mathias Krause <minipli@googlemail.com>

[ Upstream commit 3ce5efad47b62c57a4f5c54248347085a750ce0e ]

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: Steven Rostedt <rostedt@goodmis.org>
---
net/netrom/af_netrom.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/net/netrom/af_netrom.c b/net/netrom/af_netrom.c
index 7261eb8..14c106b 100644
--- a/net/netrom/af_netrom.c
+++ b/net/netrom/af_netrom.c
@@ -1177,6 +1177,7 @@ static int nr_recvmsg(struct kiocb *iocb, struct socket *sock,
}

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);
--
1.7.10.4