D7net
Home
Console
Upload
information
Create File
Create Folder
About
Tools
:
/
usr
/
share
/
doc
/
microcode_ctl
/
caveats
/
Filename :
06-4e-03_readme
back
Copy
Some Intel Skylake CPU models (SKL-U/Y, family 6, model 78, stepping 3) have reports of system hangs when revision 0xdc of microcode, that is included since microcode-20200609 update to address CVE-2020-0543, CVE-2020-0548, and CVE-2020-0549, is applied[1]. In order to address this, microcode update to the newer revision has been disabled by default on these systems, and the previously published microcode revision 0xd6 is used by default for the OS-driven microcode update. [1] https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files/issues/31 For the reference, SHA1 checksums of 06-4e-03 microcode files containing microcode revisions in question are listed below: * 06-4e-03, revision 0xd6: 06432a25053c823b0e2a6b8e84e2e2023ee3d43e * 06-4e-03, revision 0xdc: cd1733458d187486999337ff8b51eeaa0cfbca6c * 06-4e-03, revision 0xe2: 41f4513cf563605bc85db38056ac430dec948366 * 06-4e-03, revision 0xea: 5a54cab9f22f69b819d663e5747ed6ea2a326c55 * 06-4e-03, revision 0xec: d949a8543d2464d955f5dc4b0777cac863f48729 * 06-4e-03, revision 0xf0: 37475bac70457ba8df2c1a32bba81bd7bd27d5e8 Please contact your system vendor for a BIOS/firmware update that contains the latest microcode version. For the information regarding microcode versions required for mitigating specific side-channel cache attacks, please refer to the following knowledge base articles: * CVE-2017-5715 ("Spectre"): https://access.redhat.com/articles/3436091 * CVE-2018-3639 ("Speculative Store Bypass"): https://access.redhat.com/articles/3540901 * CVE-2018-3620, CVE-2018-3646 ("L1 Terminal Fault Attack"): https://access.redhat.com/articles/3562741 * CVE-2018-12130, CVE-2018-12126, CVE-2018-12127, and CVE-2019-11091 ("Microarchitectural Data Sampling"): https://access.redhat.com/articles/4138151 * CVE-2019-0117 (Intel SGX Information Leak), CVE-2019-0123 (Intel SGX Privilege Escalation), CVE-2019-11135 (TSX Asynchronous Abort), CVE-2019-11139 (Voltage Setting Modulation): https://access.redhat.com/solutions/2019-microcode-nov * CVE-2020-0543 (Special Register Buffer Data Sampling), CVE-2020-0548 (Vector Register Data Sampling), CVE-2020-0549 (L1D Cache Eviction Sampling): https://access.redhat.com/solutions/5142751 * CVE-2020-8695 (Information disclosure issue in Intel SGX via RAPL interface), CVE-2020-8696 (Vector Register Leakage-Active), CVE-2020-8698 (Fast Forward Store Predictor): https://access.redhat.com/articles/5569051 * CVE-2020-24489 (VT-d-related Privilege Escalation), CVE-2020-24511 (Improper Isolation of Shared Resources), CVE-2020-24512 (Observable Timing Discrepancy), CVE-2020-24513 (Information Disclosure on Some Intel Atom Processors): https://access.redhat.com/articles/6101171 * CVE-2021-0127 (Intel Processor Breakpoint Control Flow): https://access.redhat.com/articles/6716541 * CVE-2022-0005 (Informational disclosure via JTAG), CVE-2022-21123 (Shared Buffers Data Read), CVE-2022-21125 (Shared Buffers Data Sampling), CVE-2022-21127 (Update to Special Register Buffer Data Sampling), CVE-2022-21151 (Optimization Removal-Induced Informational Disclosure), CVE-2022-21166 (Device Register Partial Write): https://access.redhat.com/articles/6963124 The information regarding enforcing microcode update is provided below. To enforce usage of the latest 06-4e-03 microcode revision for a specific kernel version, please create a file "force-intel-06-4e-03" inside /lib/firmware/<kernel_version> directory, run "/usr/libexec/microcode_ctl/update_ucode" to add it to firmware directory where microcode will be available for late microcode update, and run "dracut -f --kver <kernel_version>", so initramfs for this kernel version is regenerated and the microcode can be loaded early, for example: touch /lib/firmware/3.10.0-862.9.1/force-intel-06-4e-03 /usr/libexec/microcode_ctl/update_ucode dracut -f --kver 3.10.0-862.9.1 After that, it is possible to perform a late microcode update by executing "/usr/libexec/microcode_ctl/reload_microcode" or by writing value "1" to "/sys/devices/system/cpu/microcode/reload" directly. To enforce addition of this microcode for all kernels, please create file "/etc/microcode_ctl/ucode_with_caveats/force-intel-06-4e-03", run "/usr/libexec/microcode_ctl/update_ucode" for enabling late microcode updates, and "dracut -f --regenerate-all" for enabling early microcode updates: mkdir -p /etc/microcode_ctl/ucode_with_caveats touch /etc/microcode_ctl/ucode_with_caveats/force-intel-06-4e-03 /usr/libexec/microcode_ctl/update_ucode dracut -f --regenerate-all Please refer to /usr/share/doc/microcode_ctl/README.caveats for additional information.