CVE-2025-38534: Linux kernel · netfs: Fix copy-to-cache so that it performs collection with ceph+fscache
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 6.14.0-1017.17~24.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.14.0-1017.17~24.04.1, 6.14.0-1020.21~24.04.1, 6.14.0-1016.16 +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7880-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7934-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.14pkg:deb/ubuntu/linux-azure-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-fde-6.14pkg:deb/ubuntu/linux-azure-fde-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-nvidia-6.14pkg:deb/ubuntu/linux-azure-nvidia-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: netfs: Fix copy-to-cache so that it performs collection with ceph+fscache The netfs copy-to-cache that is used by Ceph with local caching sets up a new request to write data just read to the cache. The request is started and then left to look after itself whilst the app continues. The request gets notified by the backing fs upon completion of the async DIO write, but then tries to wake up the app because NETFS_RREQ_OFFLOAD_COLLECTION isn't set - but the app isn't waiting there, and so the request just hangs. Fix this by setting NETFS_RREQ_OFFLOAD_COLLECTION which causes the notification from the backing filesystem to put the collection onto a work queue instead.
References
- ubuntu.com/security/CVE-2025-38534 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38534 (opens in a new tab)
- git.kernel.org/linus/4c238e30774e3022a505fa54311273add7570f13 (opens in a new tab)
- git.kernel.org/stable/c/1ebe58cef84eab22b41b4d5e72c2051ebf00af50 (opens in a new tab)
- git.kernel.org/stable/c/4c238e30774e3022a505fa54311273add7570f13 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7880-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7934-1 (opens in a new tab)