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 <[email protected]>
Signed-off-by: Mathias Krause <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
This commit is contained in:
Mathias Krause 2013-04-07 01:51:57 +00:00 • committed by David S. Miller
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);