netrom: fix info leak via msg_name in nr_recvmsg()

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>
This commit is contained in:
Mathias Krause 2013-04-07 01:51:57 +00:00 committed by David S. Miller
parent c77a4b9cff
commit 3ce5efad47

View File

@ -1173,6 +1173,7 @@ 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);