Vulnerability Database

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Total vulnerabilities in the database

CVE-2025-71225 — linux / linux_kernel

Time-of-check Time-of-use (TOCTOU) Race Condition

In the Linux kernel, the following vulnerability has been resolved:

md: suspend array while updating raid_disks via sysfs

In raid1_reshape(), freeze_array() is called before modifying the r1bio memory pool (conf->r1bio_pool) and conf->raid_disks, and unfreeze_array() is called after the update is completed.

However, freeze_array() only waits until nr_sync_pending and (nr_pending - nr_queued) of all buckets reaches zero. When an I/O error occurs, nr_queued is increased and the corresponding r1bio is queued to either retry_list or bio_end_io_list. As a result, freeze_array() may unblock before these r1bios are released.

This can lead to a situation where conf->raid_disks and the mempool have already been updated while queued r1bios, allocated with the old raid_disks value, are later released. Consequently, free_r1bio() may access memory out of bounds in put_all_bios() and release r1bios of the wrong size to the new mempool, potentially causing issues with the mempool as well.

Since only normal I/O might increase nr_queued while an I/O error occurs, suspending the array avoids this issue.

Note: Updating raid_disks via ioctl SET_ARRAY_INFO already suspends the array. Therefore, we suspend the array when updating raid_disks via sysfs to avoid this issue too.

  • Published: Feb 18, 2026
  • Updated: Mar 19, 2026
  • CVE: CVE-2025-71225
  • Severity: Medium
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: Medium
  • Score: 5.3
  • AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H

CWEs:

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