CVE-2026-46045: md/md-llbitmap: skip reading rdevs that are not in_sync
In the Linux kernel, the following vulnerability has been resolved:
md/md-llbitmap: skip reading rdevs that are not insync
When reading bitmap pages from member disks, the code iterates through all rdevs and attempts to read from the first available one. However, it only checks for raiddisk assignment and Faulty flag, missing the Insync flag check.
This can cause bitmap data to be read from spare disks that are still being rebuilt and don't have valid bitmap information yet. Reading stale or uninitialized bitmap data from such disks can lead to incorrect dirty bit tracking, potentially causing data corruption during recovery or normal operation.
Add the Insync flag check to ensure bitmap pages are only read from fully synchronized member disks that have valid bitmap data.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Modify the md/md-llbitmap bitmap-read logic to add a check for the rdev In_sync flag and skip rdevs that are not in_sync so bitmap pages are only read from fully synchronized member disks with valid bitmap data.
Linux kernel md/md-llbitmap check In_sync flag when reading bitmap pages = enabled