[096/126] ax25: fix info leak via msg_name in ax25_recvmsg()

Steven Rostedt
2013-05-07T04:38:14Z

[-- Attachment #1: 0096-ax25-fix-info-leak-via-msg_name-in-ax25_recvmsg.patch --]
[-- Type: text/plain, Size: 1439 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 ef3313e84acbf349caecae942ab3ab731471f1a1 ]

When msg_namelen is non-zero 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. Additionally the
msg_namelen value is updated to sizeof(struct full_sockaddr_ax25) but is
not always filled up to this size.

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/ax25/af_ax25.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index 779095d..d53a123 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -1647,6 +1647,7 @@ static int ax25_recvmsg(struct kiocb *iocb, struct socket *sock,
ax25_address src;
const unsigned char *mac = skb_mac_header(skb);

+ memset(sax, 0, sizeof(struct full_sockaddr_ax25));
ax25_addr_parse(mac + 1, skb->data - mac - 1, &src, NULL,
&digi, NULL, NULL);
sax->sax25_family = AF_AX25;
--
1.7.10.4