In the Linux kernel, the following vulnerability has been resolved:
md/raid10: fix still_degraded being inverted in raid10_sync_request()
Commit fe6a19d40ceb ("md/md-bitmap: merge md_bitmap_start_sync() into
bitmap_operations") converted still_degraded from int to bool, but
inverted the assignment in the loop that checks whether the array will
still be degraded after the current device is recovered:
"still_degraded = 1" became "still_degraded = false".
As a result, recovering a device while another mirror is still missing
calls md_bitmap_start_sync() with degraded == false, which clears bitmap
bits that the still-missing device needs. When that device is re-added,
its bitmap-based recovery finds the bits already cleared and skips every
region written while the array was degraded, so it is marked In_sync
while holding stale data: silent corruption.
Reproducer (raid10 near=2, 4 disks, internal bitmap):
- fail and remove one disk of each mirror pair
- write to the degraded array
- re-add both disks and let recovery finish
- "check" reports mismatch_cnt=262272 after 256 MiB of degraded
writes and file contents differ; the second disk's "recovery"
completes in milliseconds because everything is skipped
The same conversion in raid1 got it right (still_degraded = true).
Restore the correct value.
References
Configurations
No configuration.
History
No history.
Information
Published : 2026-09-11 20:19
Updated : 2026-09-13 07:17
NVD link : CVE-2026-89558
Mitre link : CVE-2026-89558
CVE.ORG link : CVE-2026-89558
JSON object : View
Products Affected
No product.
CWE
No CWE.