Description
In the Linux kernel, the following vulnerability has been resolved:
md/raid10: fix null-ptr-deref in raid10_sync_request
init_resync() inits mempool and sets conf->have_replacemnt at the beginning of sync, close_sync() frees the mempool when sync is completed.
After [1] recovery might be skipped and init_resync() is called but close_sync() is not. null-ptr-deref occurs with r10bio->dev[i].repl_bio.
The following is one way to reproduce the issue.
1) create a array, wait for resync to complete, mddev->recovery_cp is set to MaxSector. 2) recovery is woken and it is skipped. conf->have_replacement is set to 0 in init_resync(). close_sync() not called. 3) some io errors and rdev A is set to WantReplacement. 4) a new device is added and set to A's replacement. 5) recovery is woken, A have replacement, but conf->have_replacemnt is 0. r10bio->dev[i].repl_bio will not be alloced and null-ptr-deref occurs.
Fix it by not calling init_resync() if recovery skipped.
[1] commit 7e83ccbecd60 ("md/raid10: Allow skipping recovery when clean arrays are assembled")
Metrics
No CVSS score has been published yet.
Affected software
No affected versions have been published.
Timeline
- Published
- Dec 9, 2025
- Last modified
- Jun 17, 2026
- NVD status
- Deferred