Re: Question on CVE-2017-5754 on Debian 8.9

On 24 January 2018 at 22:32, Michael Lange <klappnase@freenet.de> wrote:

Hi,

On Wed, 24 Jan 2018 20:07:07 +0000
Michael Fothergill <michael.fothergill@gmail.com> wrote:

(...)
> > I tried installing the headers file and it says I have dependency
> > problems:
> >
> >
> > root@mikef-PC:/home/mikef/Downloads# dpkg -i
> > linux-headers-4.15.0-rc8-all- amd64_4.15~rc8-1~exp1_amd64.deb
> > Selecting previously unselected package linux-headers-4.15.0-rc8-all-
> > amd64.
> > (Reading database ... 222960 files and directories currently
> > installed.) Preparing to unpack linux-headers-4.15.0-rc8-all-
> > amd64_4.15~rc8-1~exp1_amd64.deb ...
> > Unpacking linux-headers-4.15.0-rc8-all-amd64 (4.15~rc8-1~exp1) ...
> > dpkg: dependency problems prevent configuration of
> > linux-headers-4.15.0-rc8-all-amd64:
> > linux-headers-4.15.0-rc8-all-amd64 depends on
> > linux-headers-4.15.0-rc8-amd64 (= 4.15~rc8-1~exp1); however:
> > Package linux-headers-4.15.0-rc8-amd64 is not installed.
> >
> > It almost sounds like some kind of rehab is required here.

no, I don't think so ;)
You just need to do what the error message from dpkg tells you and
download the linux-headers-4.15.0-rc8-amd64 package from
https://packages.debian.org/experimental/linux-headers-4.15.0-rc8-amd64
and install it along with
linux-headers-4.15.0-rc8-all-amd64_4.15~rc8-1~exp1_amd64.deb

Maybe you stumbled over the similarity between those two packages' names?

OK, I installed buster and the other dependencies and gcc 7.2.

When I upgraded then kernel 4.15.0 was installed.

I ran the patch checker:

root@mikef-PC:/home/mikef/spectre-meltdown-checker# ./spectre-meltdown-checker.sh
Spectre and Meltdown mitigation detection tool v0.32

Checking for vulnerabilities on current system
Kernel is Linux 4.15.0-rc8-amd64 #1 SMP Debian 4.15~rc8-1~exp1 (2018-01-15) x86_64
CPU is AMD A10-7850K Radeon R7, 12 Compute Cores 4C+8G

Hardware check
* Hardware support (CPU microcode) for mitigation techniques
* Indirect Branch Restricted Speculation (IBRS)
    * SPEC_CTRL MSR is available: NO
    * CPU indicates IBRS capability: NO
* Indirect Branch Prediction Barrier (IBPB)
    * PRED_CMD MSR is available: NO
    * CPU indicates IBPB capability: NO
* Single Thread Indirect Branch Predictors (STIBP)
    * SPEC_CTRL MSR is available: NO
    * CPU indicates STIBP capability: NO
* Enhanced IBRS (IBRS_ALL)
    * CPU indicates ARCH_CAPABILITIES MSR availability: NO
    * ARCH_CAPABILITIES MSR advertises IBRS_ALL capability: NO
* CPU explicitly indicates not being vulnerable to Meltdown (RDCL_NO): NO
* CPU vulnerability to the three speculative execution attacks variants
* Vulnerable to Variant 1: YES
* Vulnerable to Variant 2: YES
* Vulnerable to Variant 3: NO

CVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'
* Mitigated according to the /sys interface: NO (kernel confirms your system is vulnerable)
> STATUS: VULNERABLE (Vulnerable)

CVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'
* Mitigated according to the /sys interface: NO (kernel confirms your system is vulnerable)
* Mitigation 1
* Kernel is compiled with IBRS/IBPB support: NO
* Currently enabled features
    * IBRS enabled for Kernel space: NO
    * IBRS enabled for User space: NO
    * IBPB enabled: NO
* Mitigation 2
* Kernel compiled with retpoline option: YES
* Kernel compiled with a retpoline-aware compiler: NO (kernel reports minimal retpoline compilation)
* Retpoline enabled: YES
> STATUS: VULNERABLE (Vulnerable: Minimal AMD ASM retpoline)

CVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'
* Mitigated according to the /sys interface: YES (kernel confirms that your CPU is unaffected)
* Kernel supports Page Table Isolation (PTI): YES
* PTI enabled and active: NO
* Running under Xen PV (64 bits): NO
> STATUS: NOT VULNERABLE (your CPU vendor reported your CPU model as not vulnerable)

A false sense of security is worse than no security at all, see --disclaimer
root@mikef-PC:/home/mikef/spectre-meltdown-checker#

I have the same problem as in Gentoo.

In order to install gcc 7.3 rc2 I think I would need to be sid.

I don't think I want to be sid at present.

Cheers

Regards

Michael

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