Re: [Security] [SECURITY] CAN info leak/minor heap overflow

[Oliver Hartkopp <socketcan@hartkopp.net>]

On 02.11.2010 20:57, Linus Torvalds wrote:
> On Tue, Nov 2, 2010 at 3:53 PM, Dan Rosenberg <drosenberg@vsecurity.com> wrote:
>>
>>> Why is this bad? Can the addresses of CAN-BCM sock structs be used for
>>> anything from userspace?
>>>
>>> For me they are just intented to be unique numbers ...
>>>
>>
>> This is a bad idea because it makes exploiting other kernel
>> vulnerabilities easier.  Exposing the address of an object in a slab
>> cache, especially an object that unprivileged users have some level of
>> control of, is just an invitation to use that structure when writing
>> exploits, for heap overflows or otherwise.
> 
> Indeed. At the very least, hash them and truncate them with some
> secret per-boot value or something. Even better, use something like a
> socket number so that maybe they can be associated with
> /proc/<xyz>/fd/<x> or other system info if somebody were to care.

Good hint!

Will pick this idea.

Thanks,
Oliver