[PATCH] drivers/net/usb/hso.c: prevent reading uninitialized memory

[Dan Rosenberg]

The TIOCGICOUNT device ioctl allows unprivileged users to read 9 bytes
of uninitialized stack memory, because the "reserved" member of the
serial_icounter_struct struct declared on the stack in hso_get_count()
is not altered or zeroed before being copied back to the user.  This
patch takes care of it.

Signed-off-by: Dan Rosenberg <dan.j.rosenberg@xxxxxxxxx>

--- linux-2.6.35.4.orig/drivers/net/usb/hso.c	2010-09-11
19:12:00.000000000 -0400
+++ linux-2.6.35.4/drivers/net/usb/hso.c	2010-09-11 19:15:23.000000000 -0400
@@ -1653,6 +1653,8 @@ static int hso_get_count(struct hso_seri
 	struct uart_icount cnow;
 	struct hso_tiocmget  *tiocmget = serial->tiocmget;

+	memset(&icount, 0, sizeof(struct serial_icounter_struct));
+
 	if (!tiocmget)
 		 return -ENOENT;
 	spin_lock_irq(&serial->serial_lock);
--
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