[PATCH] uml: make daemon transport behave properly

Avoid uninitialized data in the daemon_data structure.  I used this transport
before doing proper setup before-hand, and I got some very nice SLAB
corruption due to freeing crap pointers.  So just make sure to clear
everything when appropriate.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

arch/um/drivers/daemon_kern.c

@@ -31,6 +31,10 @@ void daemon_init(struct net_device *dev, void *data)
 	dpri->fd = -1;
 	dpri->control = -1;
 	dpri->dev = dev;
+	/* We will free this pointer. If it contains crap we're burned. */
+	dpri->ctl_addr = NULL;
+	dpri->data_addr = NULL;
+	dpri->local_addr = NULL;
 
 	printk("daemon backend (uml_switch version %d) - %s:%s", 
 	       SWITCH_VERSION, dpri->sock_type, dpri->ctl_sock);

arch/um/drivers/daemon_user.c

@@ -158,10 +158,16 @@ static void daemon_remove(void *data)
 	struct daemon_data *pri = data;
 
 	os_close_file(pri->fd);
+	pri->fd = -1;
 	os_close_file(pri->control);
+	pri->control = -1;
+
 	kfree(pri->data_addr);
+	pri->data_addr = NULL;
 	kfree(pri->ctl_addr);
+	pri->ctl_addr = NULL;
 	kfree(pri->local_addr);
+	pri->local_addr = NULL;
 }
 
 int daemon_user_write(int fd, void *buf, int len, struct daemon_data *pri)