Skip to content
CVE Ledger
  • Newest CVEsPage
  • Recently added to KEVPage
  • Rising exploitation (EPSS)Page
  • Weekly digestPage
  • StatisticsPage
  • WatchlistPage
  • API docsPage
  • MCP serverPage
  • AboutPage
  • Data sourcesPage
  • Data statusPage
  • ChangelogPage
  • How it's builtPage
  • Support the projectPage

14 results

Back

CVE-2025-38508x86/sev: Use TSC_FACTOR for Secure TSC frequency calculation

Description

In the Linux kernel, the following vulnerability has been resolved: x86/sev: Use TSC_FACTOR for Secure TSC frequency calculation When using Secure TSC, the GUEST_TSC_FREQ MSR reports a frequency based on the nominal P0 frequency, which deviates slightly (typically ~0.2%) from the actual mean TSC frequency due to clocking parameters. Over extended VM uptime, this discrepancy accumulates, causing clock skew between the hypervisor and a SEV-SNP VM, leading to early timer interrupts as perceived by the guest. The guest kernel relies on the reported nominal frequency for TSC-based timekeeping, while the actual frequency set during SNP_LAUNCH_START may differ. This mismatch results in inaccurate time calculations, causing the guest to perceive hrtimers as firing earlier than expected. Utilize the TSC_FACTOR from the SEV firmware's secrets page (see "Secrets Page Format" in the SNP Firmware ABI Specification) to calculate the mean TSC frequency, ensuring accurate timekeeping and mitigating clock skew in SEV-SNP VMs. Use early_ioremap_encrypted() to map the secrets page as ioremap_encrypted() uses kmalloc() which is not available during early TSC initialization and causes a panic. [ bp: Drop the silly dummy var: https://lore.kernel.org/r/20250630192726.GBaGLlHl84xIopx4Pt@fat_crate.local ]

Timeline

  1. ID reserved

    By Linux

  2. · 4 months later

    Published

  3. · 12 months later

    Record updated

Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.

Scores

CVSS scores of CVE-2025-38508, by who scored it
Scored byCVSSScoreVector
LinuxCNA (assigner)3.1High7.3CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
NVDNVD · Modified3.1Medium5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS (exploitation in 30 days)
0.14% · top 97% of all CVEs (15 Nov 2026)
Loading the EPSS history…

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.3.

Affected products

  • Linux · Linux

    • affected 73bbf3b0fbba9aa27fef07a1fbd837661a863f03 – < d0195c42e65805938c9eb507657e7cdf8e1e9522
    • affected 73bbf3b0fbba9aa27fef07a1fbd837661a863f03 – < 52e1a03e6cf61ae165f59f41c44394a653a0a788

  • Linux · Linux

    • affected 6.14
    • unaffected < 6.14
    • unaffected 6.15.7 – ≤ 6.15.*
    • unaffected 6.16 – ≤ *

References

References2

Sources

The same CVE in the primary databases and aggregators, to check against.

Badge for a README or a ticket

CVE-2025-38508 badge
[![CVE-2025-38508](https://cveledger.app/badge/CVE-2025-38508.svg)](https://cveledger.app/cve/CVE-2025-38508)

Record last updated .