Reg : Spectre & Meltdown

Reg : Spectre & Meltdown

[Mohammed Azfar]

Hi Team

please share your suggestions about this.

I tired an online tool to check the vulnerability of spectre and meltdown, this is after upgrading 4.4.111-1 kernel version in centos 7. But its still showing in vulnerable state, im running this script in AWS instance.  Please advice me.

Script : https://raw.githubusercontent.com/speed47/spectre-meltdown-checker/master/spectre-meltdown-checker.sh

Output : 

Spectre and Meltdown mitigation detection tool v0.24


Checking for vulnerabilities against live running kernel Linux 4.4.111-1.el7.elrepo.x86_64 #1 SMP Wed Jan 10 13:12:02 EST 2018 x86_64


CVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'
* Checking count of LFENCE opcodes in kernel:  NO  (only 35 opcodes found, should be >= 70)
> STATUS:  VULNERABLE  (heuristic to be improved when official patches become available)


CVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'
* Mitigation 1
*   Hardware (CPU microcode) support for mitigation:  YES
*   Kernel support for IBRS:  NO
*   IBRS enabled for Kernel space:  NO
*   IBRS enabled for User space:  NO
* Mitigation 2
*   Kernel compiled with retpoline option:  NO
*   Kernel compiled with a retpoline-aware compiler:  NO
> STATUS:  VULNERABLE  (IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability)


CVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'
* Kernel supports Page Table Isolation (PTI):  YES
* PTI enabled and active:  YES
> STATUS:  NOT VULNERABLE  (PTI mitigates the vulnerability)


A false sense of security is worse than no security at all, see --disclaimer


--
Thanks


Mohammed Azfar

        

Re: Reg : Spectre & Meltdown

[David Lang]

you are running a RedHat kernel, you will have to ask them about what they have 
included in it.
k

Re: Reg : Spectre & Meltdown

[Akemi Yagi]

On Mon, 15 Jan 2018 13:17:17 -0800, David Lang wrote:

> you are running a RedHat kernel, you will have to ask them about what they have 
> included in it.
> k

I see that he OP is running kernel 4.4.111 as provided by ELRepo 
( http://elrepo.org/tiki/kernel-ml ).

Mohammed, try updating the microcode by downloading the latest file 
from Intel. That should take care of the issue.

Akemi

Re: Reg : Spectre & Meltdown

[David Lang]

the 4.4.112 patches that Greg just posted include a bunch of work for these 
vulnerabilities.

Who knows what has been backported to the kernel he is running.
k

Re: Reg : Spectre & Meltdown

[Akemi Yagi]

On Mon, Jan 15, 2018 at 4:50 PM, David Lang <david@lang.hm> wrote:
> the 4.4.112 patches that Greg just posted include a bunch of work for these
> vulnerabilities.
>
> Who knows what has been backported to the kernel he is running.
> k

In RHEL (therefore CentOS), microcode comes from the microcode_ctl
package which is currently at 2.1-22.2.el7. If you get the latest from
Intel ( https://downloadcenter.intel.com/download/27431/Linux-Processor-Microcode-Data-File
), that will update the microcode on your system to "date =
2017-11-20". As far as I can see, that changes the test result of
'Spectre Variant 2' from vuln to Not vuln.

Akemi