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06-5e-03_readme
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Some Intel Skylake CPU models (SKL-H/S/Xeon E3 v5, family 6, model 94, stepping 3) had reports of possible system hangs when revision 0xdc of microcode, that is included in microcode-20200609 update to address CVE-2020-0543, CVE-2020-0548, and CVE-2020-0549, was applied[1]. In order to address this, microcode updates to the newer revision had been disabled by default on these systems, and the previously published microcode revision 0xd6 was used by default for the OS-driven microcode update. The revision 0xea seems[2] to have fixed the aforementioned issue, hence it is enabled by default (but can be disabled explicitly; see below). [1] https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files/issues/31#issuecomment-644885826 [2] https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files/issues/31#issuecomment-857806014 For the reference, SHA1 checksums of 06-5e-03 microcode files containing microcode revisions in question are listed below: * 06-5e-03, revision 0xd6: 86c60ee7d5d0d7115a4962c1c61ceecb0fd3a95a * 06-5e-03, revision 0xdc: 5e1020a10678cfc60980131c3d3a2cfd462b4dd7 * 06-5e-03, revision 0xe2: 031e6e148b590d1c9cfdb6677539eeb4899e831c * 06-5e-03, revision 0xea: e6c37056a849fd281f2fdb975361a914e07b86c8 * 06-5e-03, revision 0xec: 6458bf25da4906479a01ffdcaa6d466e22722e01 * 06-5e-03, revision 0xf0: 0683706bbbf470abbdad4b9923aa9647bfec9616 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 disabling microcode update is provided below. To prevent usage of the latest 06-5e-03 microcode revision for a specific kernel version, please create a file "disallow-intel-06-5e-03" inside /lib/firmware/<kernel_version> directory, run "/usr/libexec/microcode_ctl/update_ucode" to remove it to firmware directory where microcode is available for late microcode update, and run "dracut -f --kver <kernel_version>", so initramfs for this kernel version is regenerated, for example: touch /lib/firmware/3.10.0-862.9.1/disallow-intel-06-5e-03 /usr/libexec/microcode_ctl/update_ucode dracut -f --kver 3.10.0-862.9.1 To avoid addition of the latest microcode for all kernels, please create file "/etc/microcode_ctl/ucode_with_caveats/disallow-intel-06-5e-03", run "/usr/libexec/microcode_ctl/update_ucode" for late microcode updates, and "dracut -f --regenerate-all" for early microcode updates: mkdir -p /etc/microcode_ctl/ucode_with_caveats touch /etc/microcode_ctl/ucode_with_caveats/disallow-intel-06-5e-03 /usr/libexec/microcode_ctl/update_ucode dracut -f --regenerate-all Please refer to /usr/share/doc/microcode_ctl/README.caveats for additional information.