In the Linux kernel, the following vulnerability has been resolved: md: fix mddev uaf while iterating all_mddevs list While iterating all_mddevs list from md_notify_reboot() and md_exit(), list_for_each_entry_safe is used, and this can race with deletint the next mddev, causing UAF: t1: spin_lock //list_for_each_entry_safe(mddev, n, ...) mddev_get(mddev1) // assume mddev2 is the next entry spin_unlock t2: //remove mddev2 ... mddev_free spin_lock list_del spin_unlock kfree(mddev2) mddev_put(mddev1) spin_lock //continue dereference mddev2->all_mddevs The old helper for_each_mddev() actually grab the reference of mddev2 while holding the lock, to prevent from being freed. This problem can be fixed the same way, however, the code will be complex. Hence switch to use list_for_each_entry, in this case mddev_put() can free the mddev1 and it's not safe as well. Refer to md_seq_show(), also factor out a helper mddev_put_locked() to fix this problem.
History

Wed, 30 Apr 2025 15:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Fri, 25 Apr 2025 10:30:00 +0000


Fri, 18 Apr 2025 02:45:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Wed, 16 Apr 2025 14:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: md: fix mddev uaf while iterating all_mddevs list While iterating all_mddevs list from md_notify_reboot() and md_exit(), list_for_each_entry_safe is used, and this can race with deletint the next mddev, causing UAF: t1: spin_lock //list_for_each_entry_safe(mddev, n, ...) mddev_get(mddev1) // assume mddev2 is the next entry spin_unlock t2: //remove mddev2 ... mddev_free spin_lock list_del spin_unlock kfree(mddev2) mddev_put(mddev1) spin_lock //continue dereference mddev2->all_mddevs The old helper for_each_mddev() actually grab the reference of mddev2 while holding the lock, to prevent from being freed. This problem can be fixed the same way, however, the code will be complex. Hence switch to use list_for_each_entry, in this case mddev_put() can free the mddev1 and it's not safe as well. Refer to md_seq_show(), also factor out a helper mddev_put_locked() to fix this problem.
Title md: fix mddev uaf while iterating all_mddevs list
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2025-04-16T14:13:09.399Z

Updated: 2025-04-25T10:06:48.152Z

Reserved: 2024-12-29T08:45:45.823Z

Link: CVE-2025-22126

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-04-16T15:16:06.727

Modified: 2025-04-25T11:15:45.880

Link: CVE-2025-22126

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-04-16T00:00:00Z

Links: CVE-2025-22126 - Bugzilla