Security Vulnerability: Intra-Mode Branch Target Injection / Branch History Injection - CVE-2022-0001 / CVE-2022-0002 / CVE-2021-26401
This document (000020607) is provided subject to the disclaimer at the end of this document.
Environment
For a comprehensive list of affected products please visit the SUSE CVE announcement:
- https://www.suse.com/security/cve/CVE-2022-0001.html
- https://www.suse.com/security/cve/CVE-2022-0002.html
- https://www.suse.com/security/cve/CVE-2021-26401.html
Situation
Current day CPUs use a "Branch History Buffer" and various predictions to speculate how potential future indirect branches will be taken, to already speculatively execute code ahead on those branch targets to achieve higher performance.
Security Researchers from VU Amsterdam have identified transient code execution attacks against the branch predictors, which would allow local attackers to gain otherwise confidential information, similar to the known Spectre Variant 2 attacks.
A simple attack vector to exploit these problems is using JITed eBPF programs.
Also the "EIBRS" mitigation of the Spectre v2 vulnerability on Intel x86 still was vulnerable. ( CVE-2022-0001 / CVE-2022-0002). Also the AMD specific retpoline code was vulnerable to the new attacks. ( CVE-2021-26401 )
Security Researchers from VU Amsterdam have identified transient code execution attacks against the branch predictors, which would allow local attackers to gain otherwise confidential information, similar to the known Spectre Variant 2 attacks.
A simple attack vector to exploit these problems is using JITed eBPF programs.
Also the "EIBRS" mitigation of the Spectre v2 vulnerability on Intel x86 still was vulnerable. ( CVE-2022-0001 / CVE-2022-0002). Also the AMD specific retpoline code was vulnerable to the new attacks. ( CVE-2021-26401 )
Resolution
SUSE has already disabled the use of unprivileged eBPF due to other security issues in the Linux eBPF code with kernel updates in November/December 2021. This change reduces the potential attack surface significantly. Even if EIBRS is available on Intel x86, the retpoline mitigation is used additionally. The AMD specific retpoline was vulnerable to the new attacks, it was replaced by the generic retpoline mitigation.
SUSE is releasing kernel updates with these additional mitigations against these attacks.
Lookout
Further mitigations require also gcc changes, these will be added in the near future.
SUSE is releasing kernel updates with these additional mitigations against these attacks.
Lookout
Further mitigations require also gcc changes, these will be added in the near future.
Status
Security Alert
Additional Information
CVE Pages:
Research:
Disclaimer
This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.
- Document ID:000020607
- Creation Date: 08-Mar-2022
- Modified Date:08-Mar-2022
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