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

net_sched: prio: fix a race in prio_tune()

Gerrard Tai reported a race condition in PRIO, whenever SFQ perturb timer
fires at the wrong time.

The race is as follows:

CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
|
| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()

This can be abused to underflow a parent's qlen.

Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
Advisories
Source ID Title
Debian DLA Debian DLA DLA-4327-1 linux security update
Debian DLA Debian DLA DLA-4328-1 linux-6.1 security update
Debian DSA Debian DSA DSA-5973-1 linux security update
EUVD EUVD EUVD-2025-22847 In the Linux kernel, the following vulnerability has been resolved: net_sched: prio: fix a race in prio_tune() Gerrard Tai reported a race condition in PRIO, whenever SFQ perturb timer fires at the wrong time. The race is as follows: CPU 0 CPU 1 [1]: lock root [2]: qdisc_tree_flush_backlog() [3]: unlock root | | [5]: lock root | [6]: rehash | [7]: qdisc_tree_reduce_backlog() | [4]: qdisc_put() This can be abused to underflow a parent's qlen. Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog() should fix the race, because all packets will be purged from the qdisc before releasing the lock.
Ubuntu USN Ubuntu USN USN-7681-1 Linux kernel vulnerability
Ubuntu USN Ubuntu USN USN-7681-2 Linux kernel (Oracle) vulnerability
Ubuntu USN Ubuntu USN USN-7681-3 Linux kernel (Oracle) vulnerability
Ubuntu USN Ubuntu USN USN-7682-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7682-2 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-7682-3 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7682-4 Linux kernel (Low Latency) vulnerabilities
Ubuntu USN Ubuntu USN USN-7682-5 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7682-6 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7683-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7683-2 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7683-3 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7686-1 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-7701-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7701-2 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7701-3 Linux kernel (IoT) vulnerabilities
Ubuntu USN Ubuntu USN USN-7711-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7712-1 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7712-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7719-1 Linux kernel (Raspberry Pi Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7721-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7737-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7819-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7832-1 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-7819-2 Linux kernel (Azure FIPS) vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 03 Nov 2025 18:30:00 +0000


Fri, 27 Jun 2025 14:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-366
Metrics 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'}

cvssV3_1

{'score': 6.3, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:H'}


Fri, 27 Jun 2025 10:45:00 +0000


Sat, 21 Jun 2025 12:45:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

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'}

threat_severity

Moderate


Fri, 20 Jun 2025 11:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: net_sched: prio: fix a race in prio_tune() Gerrard Tai reported a race condition in PRIO, whenever SFQ perturb timer fires at the wrong time. The race is as follows: CPU 0 CPU 1 [1]: lock root [2]: qdisc_tree_flush_backlog() [3]: unlock root | | [5]: lock root | [6]: rehash | [7]: qdisc_tree_reduce_backlog() | [4]: qdisc_put() This can be abused to underflow a parent's qlen. Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog() should fix the race, because all packets will be purged from the qdisc before releasing the lock.
Title net_sched: prio: fix a race in prio_tune()
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-11-03T17:33:50.557Z

Reserved: 2025-04-16T04:51:23.981Z

Link: CVE-2025-38083

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-06-20T12:15:21.470

Modified: 2025-11-03T18:16:01.647

Link: CVE-2025-38083

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-06-20T00:00:00Z

Links: CVE-2025-38083 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-06-23T08:20:14Z