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

cachefiles: Fix potential UAF/KASAN warning

Currently, trace_cachefiles_coherency() is being passed a pointer to a
__be64 lain over the coherency data in struct cachefiles_xattr so that it
can display the first 8 bytes. However, the data is of variable length and
could even be 0 bytes. This could lead to a UAF or KASAN warning.

Fix this by making sure the buffer has room for at least 8 bytes and that
those 8 bytes are pre-cleared.

Further, those bytes are not 8-byte aligned, so fix the tracepoint to
extract the data as four 2-byte words (they are 2-byte aligned) and
reassemble the __be64. The compiler will convert this into a single 8-byte
load where the CPU supports it.
Published: 2026-09-25
Score: n/a
EPSS: n/a
KEV: No
Impact: Use‑After‑Free in kernel memory
Action: Patch Now
AI Analysis

Impact

The cachefiles subsystem of the Linux kernel contained a potential use‑after‑free where the trace_cachefiles_coherency function was given a pointer to a __be64 over a variable‑length buffer that could be zero bytes long. The description indicates a potential use‑after‑free or KASAN warning that could allow memory corruption. Based on the description, it is inferred that an attacker with local access could read or corrupt kernel memory, potentially leading to privilege escalation or a kernel crash. The flaw is a classic use‑after‑free weakness, classified as CWE‑416.

Affected Systems

All Linux kernel releases that incorporated the original cachefiles_xattr implementation prior to the commit that introduced this patch are affected. This includes any distribution that ships a kernel version containing the vulnerable code before the patch was applied. The precise list of affected kernel versions is not numbered in the advisory, but any unpatched kernel before the commit is at risk.

Risk and Exploitability

The EPSS score is not available and the CISA KEV catalog does not list this vulnerability, indicating no known widespread exploitation. Based on the description, it is inferred that a use‑after‑free in kernel space could be high‑risk for local attackers, potentially enabling arbitrary code execution with root privileges or causing a denial‑of‑service by crashing the kernel. The severity is inferred as high, consistent with the critical nature of kernel memory corruption.

Generated by OpenCVE AI on September 25, 2026 at 13:16 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade the Linux kernel to a version that includes the cachefiles UAF fix (commit 68d459e6e609c31f96a203dd6eec60c634f155e1).
  • If a kernel upgrade cannot be performed immediately, disable the cachefiles subsystem or rebuild the kernel without it to prevent the use‑after‑free from being exercised.
  • Ensure that no vulnerable modules are loaded by verifying the running kernel version and checking that the cachefiles module is not present.

Generated by OpenCVE AI on September 25, 2026 at 13:16 UTC.

Tracking

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Advisories

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History

Fri, 25 Sep 2026 13:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Fri, 25 Sep 2026 10:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: cachefiles: Fix potential UAF/KASAN warning Currently, trace_cachefiles_coherency() is being passed a pointer to a __be64 lain over the coherency data in struct cachefiles_xattr so that it can display the first 8 bytes. However, the data is of variable length and could even be 0 bytes. This could lead to a UAF or KASAN warning. Fix this by making sure the buffer has room for at least 8 bytes and that those 8 bytes are pre-cleared. Further, those bytes are not 8-byte aligned, so fix the tracepoint to extract the data as four 2-byte words (they are 2-byte aligned) and reassemble the __be64. The compiler will convert this into a single 8-byte load where the CPU supports it.
Title cachefiles: Fix potential UAF/KASAN warning
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-25T10:36:02.319Z

Reserved: 2026-09-25T10:25:14.317Z

Link: CVE-2026-98117

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-25T11:17:42.920

Modified: 2026-09-25T11:17:42.920

Link: CVE-2026-98117

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-25T13:30:19Z

Weaknesses