SB2026091283 - Improper handling of exceptional conditions in Linux kernel nfsd

Description

This security bulletin contains information about 1 vulnerability.

1) Improper handling of exceptional conditions (CVE-ID: CVE-2026-89706)

CWE-ID: CWE-755 - Improper Handling of Exceptional Conditions

CVSSv4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to cause copied data to be silently lost.

The vulnerability exists due to improper handling of writeback errors in the NFS server async COPY operation in _nfsd_copy_file_range() when processing an asynchronous COPY request whose writeback fails. A remote attacker can issue an asynchronous COPY request that encounters a writeback failure to cause copied data to be silently lost.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/31d4d0a62ec4bafbcdbad142f11ab1f90794b1d0
• https://git.kernel.org/stable/c/591134e059e3456180244a826d6917cdc183140b
• https://git.kernel.org/stable/c/bf0cd31a9abcb728c17d79b4c2cc533612a8b6af
• https://git.kernel.org/stable/c/f5cb2276954cb80987a93ef9f9dfbfdbfc0f10b9