CVE-2026-89558

A flaw was found in the Linux kernel's md/raid10 (RAID10) driver. This vulnerability occurs when a RAID10 array is in a degraded state and a device is being recovered while another mirror is still missing. Due to an inverted boolean value, the system incorrectly clears necessary bitmap bits, causing subsequent recovery operations to skip regions with stale data. This can lead to silent data corruption on the re-added device, impacting data integrity.

A logic error in md/raid10 recovery can clear bitmap bits too early when one mirror is being recovered while another mirror is still missing. A later re add of the missing device can then skip regions written while the array was degraded, causing the device to be marked In_sync while it still contains stale data. This is silent storage corruption rather than a kernel memory corruption bug. For the CVSS the PR:L is used for the paranoid score because a reduced capability storage admin, container root, or service account with md control could trigger recovery operations without full host administration. The issue is not directly network reachable. Impact is high integrity loss and possible availability impact through corrupted filesystems or application data.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.