CVE-2025-68313: x86/CPU/AMD: Add RDSEED fix for Zen5
In the Linux kernel, the following vulnerability has been resolved:
x86/CPU/AMD: Add RDSEED fix for Zen5
There's an issue with RDSEED's 16-bit and 32-bit register output variants on Zen5 which return a random value of 0 "at a rate inconsistent with randomness while incorrectly signaling success (CF=1)". Search the web for AMD-SB-7055 for more detail.
Add a fix glue which checks microcode revisions.
[ bp: Add microcode revisions checking, rewrite. ]
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
Check and verify AMD microcode revisions on affected Zen5 systems (RDSEED 16-bit/32-bit register output randomness with incorrect success signaling per AMD-SB-7055); ensure the microcode includes the fix that adds microcode revision checking and the RDSEED fix for Zen5.
Event History
Frequently Asked Questions
What is the severity of CVE-2025-68313?
CVE-2025-68313 has been classified with a severity level that indicates potential risks associated with randomness in cryptographic operations.
How do I fix CVE-2025-68313?
To address CVE-2025-68313, ensure that your Linux kernel is updated to a version that includes the recent patches for RDSEED fixes.
Which systems are affected by CVE-2025-68313?
CVE-2025-68313 primarily affects systems utilizing the AMD Linux kernel on Zen5 architecture.
What impact does CVE-2025-68313 have on system security?
CVE-2025-68313 can potentially weaken cryptographic functions by producing non-random outputs, leading to vulnerabilities in sensitive applications.
Is there a workaround for CVE-2025-68313 while waiting for a patch?
Currently, the best mitigation for CVE-2025-68313 is to apply the available patches rather than relying on a specific workaround.