Re: [PATCH 2.6.28] bluetooth: fix leak of uninitialized data to userspace

Marcel Holtmann
2008-10-05T16:32:31Z

Hi Vegard,

> From 45be27894a18f87b71b855fcc4afd50f860254b4 Mon Sep 17 00:00:00 2001
> From: Vegard Nossum <vegard.nossum@gmail.com>
> Date: Sun, 5 Oct 2008 17:25:45 +0200
> Subject: [PATCH] bluetooth: fix leak of uninitialized data to userspace
>
> struct hci_dev_list_req {
> __u16 dev_num;
> struct hci_dev_req dev_req[0]; /* hci_dev_req structures */
> };
>
> sizeof(struct hci_dev_list_req) == 4, so the two bytes immediately
> following "dev_num" will never be initialized. When this structure
> is copied to userspace, these uninitialized bytes are leaked.
>
> Fix by using kzalloc() instead of kmalloc(). Found using kmemcheck.

good catch. I thought we moved everything over to kzalloc, but as it
seems we forgot at least one. Applied your patch to me tree. Thanks.

Regards

Marcel