CVE-2026-98117: cachefiles: Fix potential UAF/KASAN warning

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-25 · updated 2026-10-28
Weakness: CWE-416

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.

Affected products

Linux kernel: from 6.14 before 6.18.53; from 6.19 before 7.2.7; 7.3-rc1, 7.3-rc2 — fixed in 6.18.53, 7.2.7
Linux kernel: 6.14 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 6.18.53, 7.2.7; Linux kernel 7.3. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-98117 or the next vulnerability affects your stack