Re: Zenbleed

From: Jung-uk Kim <jkim_at_FreeBSD.org>
Date: Thu, 27 Jul 2023 17:38:09 UTC 
On 23. 7. 27., Jung-uk Kim wrote:
> On 23. 7. 27., mike tancsa wrote:
>> On 7/26/2023 5:46 PM, Shawn Webb wrote:
>>> On Wed, Jul 26, 2023 at 08:34:56PM +0000, 0x1eef wrote:
>>>> Hello,
>>>>
>>>> I was curious if there are plans to apply the "chicken bit"
>>>> workaround for the Ryzen line of processors. A firmware
>>>> update is not scheduled to be released until Nov or Dec
>>>> at the earliest. Thanks.
>>> For those that would like to test if their systems are affected, this
>>> proof-of-concept was reported to work on at least one system:
>>>
>>> https://git.hardenedbsd.org/shawn.webb/zenbleed/-/tree/shawn.webb/bsd/main
>>>
>>> Building it depends on gmake and nasm. You'll want to be on the
>>> shawn.webb/bsd/main branch.
>>
>> Thanks for that. Is there a way to compile on RELENG_12 or is it 13 
>> only ?
>>
>> % gmake
>> cc -O0 -ggdb3 -march=znver2   -c -o pattern.o pattern.c
>> pattern.c:15:10: fatal error: 'sys/sysinfo.h' file not found
>> #include <sys/sysinfo.h>
>>           ^~~~~~~~~~~~~~~
>> 1 error generated.
>> gmake: *** [<builtin>: pattern.o] Error 1
> 
> I guess you checked out a wrong branch.  Please see the attached minimal 
> patch I made for FreeBSD.  I think it will work on any supported FreeBSD 
> branches.  Note the original exploit is available from here:
> 
> https://lock.cmpxchg8b.com/files/zenbleed-v5.tar.gz

With the forgotten attachment.

Jung-uk Kim