Vulnerability in Linux kernel (CVE-2025-38321)
Summary
Vulnerability in Linux kernel (CVE-2025-38321). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
smb: Log an error when close_all_cached_dirs fails
Under low-memory conditions, close_all_cached_dirs() can't move the
dentries to a separate list to dput() them once the locks are dropped.
This will result in a "Dentry still in use" error, so add an error
message that makes it clear this is what happened:
[ 495.281119] CIFS: VFS: \otters.example.com\share Out of memory while dropping dentries
[ 495.281595] ------------[ cut here ]------------
[ 495.281887] BUG: Dentry ffff888115531138{i=78,n=/} still in use (2) [unmount of cifs cifs]
[ 495.282391] WARNING: CPU: 1 PID: 2329 at fs/dcache.c:1536 umount_check+0xc8/0xf0
Also, bail out of looping through all tcons as soon as a single
allocation fails, since we're already in trouble, and kmalloc() attempts
for subseqeuent tcons are likely to fail just like the first one did.
Source: NIST National Vulnerability Database NVD
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-2025-38321 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-2025-38321" on the vendor's site.
CVE-2025-38321 (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
-
1Identify 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。
-
2Post-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。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2025-38321 linux-lts Fixed in: 6.18.35-r1
- Debian DEBIAN-CVE-2025-38321 linux Fixed in: 6.12.35-1
- Ubuntu UBUNTU-CVE-2025-38321 linux
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org