Ubuntu
intel-microcode package

What is the advantage of having intel-microcode?

Asked by corrado venturini on 2018-03-23

On my Ubuntu 18.04 i run spectre-meltdown-checker before and after installing intel-microcode.
From spectre-meltdown-checker I don't see difference for my vulnerability, so what is the advantage of having intel-microcode?
thanks.

this is the report before installing intel-microcode

corrado@corrado-p13-bb-0319:~$ apt policy intel-microcode
intel-microcode:
  Installed: (none)
  Candidate: 3.20180312.0~ubuntu18.04.1
  Version table:
     3.20180312.0~ubuntu18.04.1 500
        500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages
corrado@corrado-p13-bb-0319:~$ sudo ./spectre-meltdown-checker.sh
[sudo] password for corrado:
Spectre and Meltdown mitigation detection tool v0.35

Checking for vulnerabilities on current system
Kernel is Linux 4.15.0-12-generic #13-Ubuntu SMP Thu Mar 8 06:24:47 UTC 2018 x86_64
CPU is Intel(R) Core(TM) i3-7100 CPU @ 3.90GHz

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 microcode is known to cause stability problems: NO (model 158 stepping 9 ucode 0x3a)
* CPU vulnerability to the three speculative execution attacks variants
  * Vulnerable to Variant 1: YES
  * Vulnerable to Variant 2: YES
  * Vulnerable to Variant 3: YES

CVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'
* Mitigated according to the /sys interface: YES (kernel confirms that the mitigation is active)
* Kernel has array_index_mask_nospec: YES (1 occurence(s) found of 64 bits array_index_mask_nospec())
* Kernel has the Red Hat/Ubuntu patch: NO
> STATUS: NOT VULNERABLE (Mitigation: __user pointer sanitization)

CVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'
* Mitigated according to the /sys interface: YES (kernel confirms that the mitigation is active)
* 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: YES (kernel reports full retpoline compilation)
> STATUS: NOT VULNERABLE (Mitigation: Full generic retpoline)

CVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'
* Mitigated according to the /sys interface: YES (kernel confirms that the mitigation is active)
* Kernel supports Page Table Isolation (PTI): YES
* PTI enabled and active: YES
* Running as a Xen PV DomU: NO
> STATUS: NOT VULNERABLE (Mitigation: PTI)

A false sense of security is worse than no security at all, see --disclaimer
corrado@corrado-p13-bb-0319:~$

this is the report with intel-microcode installed

corrado@corrado-p13-bb-0319:~$ apt policy intel-microcode
intel-microcode:
  Installed: 3.20180312.0~ubuntu18.04.1
  Candidate: 3.20180312.0~ubuntu18.04.1
  Version table:
*** 3.20180312.0~ubuntu18.04.1 500
        500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages
        100 /var/lib/dpkg/status
corrado@corrado-p13-bb-0319:~$ sudo ./spectre-meltdown-checker.sh
[sudo] password for corrado:
Spectre and Meltdown mitigation detection tool v0.35

Checking for vulnerabilities on current system
Kernel is Linux 4.15.0-12-generic #13-Ubuntu SMP Thu Mar 8 06:24:47 UTC 2018 x86_64
CPU is Intel(R) Core(TM) i3-7100 CPU @ 3.90GHz

Hardware check
* Hardware support (CPU microcode) for mitigation techniques
  * Indirect Branch Restricted Speculation (IBRS)
    * SPEC_CTRL MSR is available: YES
    * CPU indicates IBRS capability: YES (SPEC_CTRL feature bit)
  * Indirect Branch Prediction Barrier (IBPB)
    * PRED_CMD MSR is available: YES
    * CPU indicates IBPB capability: YES (SPEC_CTRL feature bit)
  * Single Thread Indirect Branch Predictors (STIBP)
    * SPEC_CTRL MSR is available: YES
    * CPU indicates STIBP capability: YES
  * 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 microcode is known to cause stability problems: NO (model 158 stepping 9 ucode 0x84)
* CPU vulnerability to the three speculative execution attacks variants
  * Vulnerable to Variant 1: YES
  * Vulnerable to Variant 2: YES
  * Vulnerable to Variant 3: YES