|
 |
81200a |
Some Intel Skylake CPU models (SKL-H/S/Xeon E3 v5, family 6, model 94,
|
|
|
fe8809 |
stepping 3) had reports of possible system hangs when revision 0xdc
|
|
|
81200a |
of microcode, that is included in microcode-20200609 update to address
|
|
|
fe8809 |
CVE-2020-0543, CVE-2020-0548, and CVE-2020-0549, was applied[1]. In order
|
|
|
fe8809 |
to address this, microcode updates to the newer revision had been disabled
|
|
|
81200a |
by default on these systems, and the previously published microcode revision
|
|
|
fe8809 |
0xd6 was used by default for the OS-driven microcode update. The revision
|
|
|
fe8809 |
0xea seems[2] to have fixed the aforementioned issue, hence it is enabled
|
|
|
fe8809 |
by default (but can be disabled explicitly; see below).
|
|
|
81200a |
|
|
|
81200a |
[1] https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files/issues/31#issuecomment-644885826
|
|
|
fe8809 |
[2] https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files/issues/31#issuecomment-857806014
|
|
|
81200a |
|
|
|
c56524 |
For the reference, SHA1 checksums of 06-5e-03 microcode files containing
|
|
|
81200a |
microcode revisions in question are listed below:
|
|
|
81200a |
* 06-5e-03, revision 0xd6: 86c60ee7d5d0d7115a4962c1c61ceecb0fd3a95a
|
|
|
81200a |
* 06-5e-03, revision 0xdc: 5e1020a10678cfc60980131c3d3a2cfd462b4dd7
|
|
|
c56524 |
* 06-5e-03, revision 0xe2: 031e6e148b590d1c9cfdb6677539eeb4899e831c
|
|
|
fe8809 |
* 06-5e-03, revision 0xea: e6c37056a849fd281f2fdb975361a914e07b86c8
|
|
|
81200a |
|
|
|
81200a |
Please contact your system vendor for a BIOS/firmware update that contains
|
|
|
81200a |
the latest microcode version. For the information regarding microcode versions
|
|
|
81200a |
required for mitigating specific side-channel cache attacks, please refer
|
|
|
81200a |
to the following knowledge base articles:
|
|
|
81200a |
* CVE-2017-5715 ("Spectre"):
|
|
|
81200a |
https://access.redhat.com/articles/3436091
|
|
|
81200a |
* CVE-2018-3639 ("Speculative Store Bypass"):
|
|
|
81200a |
https://access.redhat.com/articles/3540901
|
|
|
81200a |
* CVE-2018-3620, CVE-2018-3646 ("L1 Terminal Fault Attack"):
|
|
|
81200a |
https://access.redhat.com/articles/3562741
|
|
|
81200a |
* CVE-2018-12130, CVE-2018-12126, CVE-2018-12127, and CVE-2019-11091
|
|
|
81200a |
("Microarchitectural Data Sampling"):
|
|
|
81200a |
https://access.redhat.com/articles/4138151
|
|
|
81200a |
* CVE-2019-0117 (Intel SGX Information Leak),
|
|
|
81200a |
CVE-2019-0123 (Intel SGX Privilege Escalation),
|
|
|
81200a |
CVE-2019-11135 (TSX Asynchronous Abort),
|
|
|
81200a |
CVE-2019-11139 (Voltage Setting Modulation):
|
|
|
81200a |
https://access.redhat.com/solutions/2019-microcode-nov
|
|
|
81200a |
* CVE-2020-0543 (Special Register Buffer Data Sampling),
|
|
|
81200a |
CVE-2020-0548 (Vector Register Data Sampling),
|
|
|
81200a |
CVE-2020-0549 (L1D Cache Eviction Sampling):
|
|
|
81200a |
https://access.redhat.com/solutions/5142751
|
|
|
c56524 |
* CVE-2020-8695 (Information disclosure issue in Intel SGX via RAPL interface),
|
|
|
c56524 |
CVE-2020-8696 (Vector Register Leakage-Active),
|
|
|
c56524 |
CVE-2020-8698 (Fast Forward Store Predictor):
|
|
|
c56524 |
https://access.redhat.com/articles/5569051
|
|
|
fe8809 |
* CVE-2020-24489 (VT-d-related Privilege Escalation),
|
|
|
fe8809 |
CVE-2020-24511 (Improper Isolation of Shared Resources),
|
|
|
fe8809 |
CVE-2020-24512 (Observable Timing Discrepancy),
|
|
|
fe8809 |
CVE-2020-24513 (Information Disclosure on Some Intel Atom Processors):
|
|
|
fe8809 |
https://access.redhat.com/articles/6101171
|
|
|
81200a |
|
|
|
fe8809 |
The information regarding disabling microcode update is provided below.
|
|
|
81200a |
|
|
|
fe8809 |
To prevent usage of the latest 06-5e-03 microcode revision for a specific kernel
|
|
|
fe8809 |
version, please create a file "disallow-intel-06-5e-03" inside
|
|
|
81200a |
/lib/firmware/<kernel_version> directory, run
|
|
|
fe8809 |
"/usr/libexec/microcode_ctl/update_ucode" to remove it to firmware directory
|
|
|
fe8809 |
where microcode is available for late microcode update, and run
|
|
|
81200a |
"dracut -f --kver <kernel_version>", so initramfs for this kernel version
|
|
|
fe8809 |
is regenerated, for example:
|
|
|
81200a |
|
|
|
fe8809 |
touch /lib/firmware/3.10.0-862.9.1/disallow-intel-06-5e-03
|
|
|
81200a |
/usr/libexec/microcode_ctl/update_ucode
|
|
|
81200a |
dracut -f --kver 3.10.0-862.9.1
|
|
|
81200a |
|
|
|
fe8809 |
To avoid addition of the latest microcode for all kernels, please create file
|
|
|
fe8809 |
"/etc/microcode_ctl/ucode_with_caveats/disallow-intel-06-5e-03", run
|
|
|
fe8809 |
"/usr/libexec/microcode_ctl/update_ucode" for late microcode updates,
|
|
|
fe8809 |
and "dracut -f --regenerate-all" for early microcode updates:
|
|
|
81200a |
|
|
|
81200a |
mkdir -p /etc/microcode_ctl/ucode_with_caveats
|
|
|
fe8809 |
touch /etc/microcode_ctl/ucode_with_caveats/disallow-intel-06-5e-03
|
|
|
81200a |
/usr/libexec/microcode_ctl/update_ucode
|
|
|
81200a |
dracut -f --regenerate-all
|
|
|
81200a |
|
|
|
81200a |
Please refer to /usr/share/doc/microcode_ctl/README.caveats for additional
|
|
|
81200a |
information.
|