SB2026072071 - Incorrect calculation in Linux kernel netfs

Description

This security bulletin contains information about 1 vulnerability.

1) Incorrect calculation (CVE-ID: CVE-2026-64159)

CWE-ID: CWE-682 - Incorrect Calculation

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause incorrect file reads.

The vulnerability exists due to improper handling of file size state in netfs_release_folio() when releasing a folio while uncommitted page cache data exists beyond the folio and the on-server EOF falls within that folio. A local user can trigger this condition through crafted file operations to cause incorrect file reads.

This was observed on cifs with the default cache option and no fscache.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/4543a4d737944134a1394afe797622546fbcc98a
• https://git.kernel.org/stable/c/5cd5207de519ef0c085f4f559adf5eefcb4c5202