Vulnerability in Linux kernel
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-2025-38434 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2025-38434" on the vendor's site.
CVE-2025-38434 (Linux kernel) — CVSS v3 7.8
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.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: High (CVSS 7.8/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
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
Identify exposureidentify
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
Post-deployment verificationverify
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。
Affected packages
| Ecosystem | Package | Affected | Fixed |
|---|---|---|---|
| Linux | Kernel |
≥ 6.10.0, < 6.12.36 ≥ 6.13.0, < 6.15.5 |
6.12.36 6.15.5 |
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2025-38434 linux-lts Fixed in: 6.12.41-r0
- Debian DEBIAN-CVE-2025-38434 linux Fixed in: 6.12.37-1
- Ubuntu UBUNTU-CVE-2025-38434 linux-hwe-edge
Original description The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
Revert "riscv: Define TASK_SIZE_MAX for __access_ok()"
This reverts commit ad5643cf2f69 ("riscv: Define TASK_SIZE_MAX for
__access_ok()").
This commit changes TASK_SIZE_MAX to be LONG_MAX to optimize access_ok(),
because the previous TASK_SIZE_MAX (default to TASK_SIZE) requires some
computation.
The reasoning was that all user addresses are less than LONG_MAX, and all
kernel addresses are greater than LONG_MAX. Therefore access_ok() can
filter kernel addresses.
Addresses between TASK_SIZE and LONG_MAX are not valid user addresses, but
access_ok() let them pass. That was thought to be okay, because they are
not valid addresses at hardware level.
Unfortunately, one case is missed: get_user_pages_fast() happily accepts
addresses between TASK_SIZE and LONG_MAX. futex(), for instance, uses
get_user_pages_fast(). This causes the problem reported by Robert [1].
Therefore, revert this commit. TASK_SIZE_MAX is changed to the default:
TASK_SIZE.
This unfortunately reduces performance, because TASK_SIZE is more expensive
to compute compared to LONG_MAX. But correctness first, we can think about
optimization later, if required.
Source: NIST National Vulnerability Database NVD
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org