Bug 2061700 (CVE-2021-26401)

Summary: CVE-2021-26401 hw: cpu: LFENCE/JMP Mitigation Update for CVE-2017-5715
Product: [Other] Security Response Reporter: Petr Matousek <pmatouse>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: acaringi, bhu, brdeoliv, chwhite, crwood, dhoward, dvlasenk, fhrbata, fpacheco, hkrzesin, jarod, jburrell, jfaracco, jforbes, jlelli, joe.lawrence, jshortt, jstancek, jwyatt, kcarcia, kernel-mgr, lgoncalv, lzampier, mvanderw, nmurray, ptalbert, qzhao, rvrbovsk, scweaver, security-response-team, vkumar, walters, williams
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in hw. The speculative execution window of AMD LFENCE/JMP mitigation (MITIGATION V2-2) may be large enough to be exploited on AMD CPUs.
Story Points: ---
Clone Of: Environment:
Last Closed: 2022-05-11 17:15:20 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2062164, 2062165, 2062166, 2062167, 2062168, 2062169, 2062633, 2062790, 2062792    
Bug Blocks: 2053116    

Description Petr Matousek 2022-03-08 11:06:46 UTC
The speculative execution window of AMD LFENCE/JMP  mitigation (MITIGATION V2-2) may be large enough to be  exploited on AMD CPUs. 

An Intel PoC (proof of concept) demonstrates that the  speculative execution window for an incorrect indirect branch  prediction using an LFENCE/JMP sequence may potentially be  large enough to allow exploitation using CVE-2017-5715. This  was observed on AMD CPUs codenamed “Zen”, “Zen+”, “Zen 2”, and “Zen 3” using a specific workload on a Simultaneous  Multi-Threading (SMT) sibling thread.

Comment 8 errata-xmlrpc 2022-05-10 14:41:07 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:1975 https://access.redhat.com/errata/RHSA-2022:1975

Comment 9 errata-xmlrpc 2022-05-10 14:47:18 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2022:1988 https://access.redhat.com/errata/RHSA-2022:1988

Comment 10 Product Security DevOps Team 2022-05-11 17:15:17 UTC
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2021-26401

Comment 11 errata-xmlrpc 2023-01-17 09:01:51 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6 Extended Lifecycle Support

Via RHSA-2023:0187 https://access.redhat.com/errata/RHSA-2023:0187

Comment 12 errata-xmlrpc 2023-01-24 10:09:26 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2023:0399 https://access.redhat.com/errata/RHSA-2023:0399

Comment 13 errata-xmlrpc 2023-01-24 10:09:48 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2023:0400 https://access.redhat.com/errata/RHSA-2023:0400