Annotation of wikisrc/security/intel_mds.mdwn, revision 1.6

1.4       maxv        1: [[!meta title="Intel MDS"]]
                      2: 
1.6     ! maxv        3: #NetBSD Security Update for the amd64 port (x86_64 architecture) - 20190514
1.1       wiki        4: 
                      5: ###Description
                      6: Details and mitigation information about a sub-class of speculative execution
                      7: side-channel vulnerabilities called Microarchitectural Data Sampling (MDS) affecting
                      8: hardware starting with select 8th and 9th Generation Intel® CoreTM processors, as
                      9: well as the 2nd Generation Intel® Xeon® Scalable Processor Family.
                     10: 
1.6     ! maxv       11: Please refer to the Intel Security Advisory 00233 located at:
1.4       maxv       12: [Intel website](https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00233.html).
1.1       wiki       13: 
                     14: This update is mitigation for the following CVEs:
                     15: 
                     16: ###Common Vulnerabilities and Exposures (CVE) / Common Vulnerability Scoring System (CVSS)
1.6     ! maxv       17: * Microarchitectural Load Port Data Sampling (MLPDS), CVE-2018-12127
1.5       maxv       18: > CVSS: 6.5 Medium
1.1       wiki       19: 
1.6     ! maxv       20: * Microarchitectural Store Buffer Data Sampling (MSBDS), CVE-2018-12126
1.5       maxv       21: > CVSS: 6.5 Medium
1.1       wiki       22: 
1.6     ! maxv       23: * Microarchitectural Fill Buffer Data Sampling (MFBDS), CVE-2018-12130
1.5       maxv       24: > CVSS: 6.5 Medium
1.1       wiki       25: 
1.6     ! maxv       26: * Microarchitectural Uncacheable Data Sampling (MDSUM), CVE-2019-11091
1.5       maxv       27: > CVSS: 3.8 Low
1.1       wiki       28: 
                     29: ##Status of the Fix
1.6     ! maxv       30: 
        !            31: NetBSD-7, and all the anterior releases, have no planned fixes.
1.1       wiki       32: 
                     33: [[!table data="""
1.4       maxv       34: Port           |Vendor/Model   |MDS            |NetBSD-8               |NetBSD-current
                     35: amd64          |Intel          |Vulnerable     |Fixed [VERW][smtoff]   |Fixed [VERW][smtoff]
1.1       wiki       36: """]]
                     37: 
                     38: ###Mitigation
1.6     ! maxv       39: 
1.1       wiki       40: The mitigation for MDS depends on the Intel CPU model and available microcode
                     41: or motherboard BIOS revision.
                     42: 
                     43: Should a motherboard manufacturer not have a BIOS update with the MDS fix for
                     44: the affected Intel processors, you may use NetBSD's pkgsrc to fetch the latest
                     45: microcode distribution from Intel. The package is **sysutils/intel-microcode-netbsd**. 
                     46: 
                     47: You may also want to disable SMT/HyperThreading to address certain aspects of
                     48: the vulnerabilities. Should you not be able to disable SMT/HT in your BIOS, you
                     49: can put **smtoff=YES** in your */etc/rc.conf* file.
                     50: 
                     51: ###Enabling the mitigation
                     52: 
                     53: The two following sysctls are now available:
1.4       maxv       54: 
                     55: [[!template id=programlisting text="""
                     56: machdep.mds.mitigated = {0/1} user-settable
                     57: machdep.mds.method = {string} constructed by the kernel
                     58: """]]
1.1       wiki       59: 
                     60: If the BIOS has the MDS update, then NetBSD will have set machdep.mds.mitigated=1 automatically.  
                     61: 
1.4       maxv       62: To manually enable the check, use "sysctl -w machdep.mds.mitigated=1".  NetBSD
1.1       wiki       63: will then determine if it can apply the available mitigation.  When set to 0, then
                     64: NetBSD will disable the mitigation.
                     65: 
1.6     ! maxv       66: Note: "method" will then show a "[VERW]" if it is enabled, and "(none)" if not.

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