Sign in Sign up
JA · EN · FR
SecPulse
Categories
CVE-2025-38100 medium CVSS 5.5

Vulnerability in Linux kernel (CVE-2025-38100)

Summary

Vulnerability in Linux kernel (CVE-2025-38100). Risk of unauthorized operations or information disclosure.

Original description

The description as published by the source.

In the Linux kernel, the following vulnerability has been resolved:

x86/iopl: Cure TIF_IO_BITMAP inconsistencies

io_bitmap_exit() is invoked from exit_thread() when a task exists or
when a fork fails. In the latter case the exit_thread() cleans up
resources which were allocated during fork().

io_bitmap_exit() invokes task_update_io_bitmap(), which in turn ends up
in tss_update_io_bitmap(). tss_update_io_bitmap() operates on the
current task. If current has TIF_IO_BITMAP set, but no bitmap installed,
tss_update_io_bitmap() crashes with a NULL pointer dereference.

There are two issues, which lead to that problem:

  1. io_bitmap_exit() should not invoke task_update_io_bitmap() when
    the task, which is cleaned up, is not the current task. That's a
    clear indicator for a cleanup after a failed fork().

  2. A task should not have TIF_IO_BITMAP set and neither a bitmap
    installed nor IOPL emulation level 3 activated.

    This happens when a kernel thread is created in the context of
    a user space thread, which has TIF_IO_BITMAP set as the thread
    flags are copied and the IO bitmap pointer is cleared.

    Other than in the failed fork() case this has no impact because
    kernel threads including IO workers never return to user space and
    therefore never invoke tss_update_io_bitmap().

Cure this by adding the missing cleanups and checks:

  1. Prevent io_bitmap_exit() to invoke task_update_io_bitmap() if
    the to be cleaned up task is not the cur…

Source: NIST National Vulnerability Database NVD GitHub Advisory

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2025-38100 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure. CVSS score: 5.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2025-38100" on the vendor's site.

CVE-2025-38100 (Linux kernel) — CWE-476 / CVSS v3 5.5
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (CWE-476) exists in Linux kernel.

📍 Affected scope

Check the vendor advisory for the affected versions of Linux kernel.

🔥 Severity

Severity: Medium (CVSS 5.5/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify 
    Audit SBOM/dependencies for affected components.

    資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。

  2. 2
    Post-deployment verification verify 
    Confirm patched version is live in production

    パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Fix status by distribution

Fixed packages published by each distribution for this CVE

References

We use cookies for analytics and ad measurement. This setting applies to all Game co., Ltd. sites. Details