SB20260912226 - Always-Incorrect Control Flow Implementation in Linux kernel md driver

Description

This security bulletin contains information about 1 vulnerability.

1) Always-Incorrect Control Flow Implementation (CVE-ID: CVE-2026-89558)

CWE-ID: CWE-670 - Always-Incorrect Control Flow Implementation

CVSSv4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a local privileged user to cause silent data corruption.

The vulnerability exists due to incorrect control flow implementation in raid10_sync_request() in drivers/md/raid10.c when recovering RAID10 devices while another mirror remains missing. A local privileged user can write to a degraded RAID10 array and re-add affected devices to cause silent data corruption.

Exploitation requires bitmap-based recovery.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/00449d752bee9c8787f42ea1bf533a9fb17f9b6b
• https://git.kernel.org/stable/c/0efabe6229dc683dbf6eeebd0f9fddc7971ed420
• https://git.kernel.org/stable/c/47f1441b281decde6954a2fa82b4131637d685ac
• https://git.kernel.org/stable/c/9bb8da6ecb330a5b1ac9b96f1e55f134a7aef1d4