CVE-2025-38534
CVE-2025-38534 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.
Key facts
- Severity: Medium (CVSS 3.x base score 5.5)
- EPSS exploit prediction: 0% (2nd percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2025-27889
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2025-38534?
- 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.
- How severe is CVE-2025-38534?
- CVE-2025-38534 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2025-38534 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2025-38534?
- CVE-2025-38534 primarily affects Linux Linux Kernel. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2025-38534?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2025-38534 have an EU (EUVD) identifier?
- Yes. CVE-2025-38534 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-27889.
- When was CVE-2025-38534 published?
- CVE-2025-38534 was published on 2025-08-16 and last updated on 2026-06-17.
References
- https://git.kernel.org/stable/c/1ebe58cef84eab22b41b4d5e72c2051ebf00af50
- https://git.kernel.org/stable/c/4c238e30774e3022a505fa54311273add7570f13
Affected products (7)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:6.16:rc4:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:6.16:rc5:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:6.16:rc6:*:*:*:*:*:*
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