CVE-2025-38083: Linux kernel · net_sched: prio: fix a race in prio_tune()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.4.0-1149.159~18.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.4.0-1149.159~18.04.1, 5.4.0-1154.161~18.04.1, 5.4.0-1152.161~18.04.1 +84
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7681-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7682-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7683-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7681-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7682-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7682-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7683-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7683-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7682-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7686-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7681-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7682-5 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- ubuntu.com/security/CVE-2025-38083 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38083 (opens in a new tab)
- git.kernel.org/linus/d35acc1be3480505b5931f17e4ea9b7617fea4d3 (opens in a new tab)
- git.kernel.org/stable/c/46c15c9d0f65c9ba857d63f53264f4b17e8a715f (opens in a new tab)
- git.kernel.org/stable/c/93f9eeb678d4c9c1abf720b3615fa8299a490845 (opens in a new tab)
- git.kernel.org/stable/c/d35acc1be3480505b5931f17e4ea9b7617fea4d3 (opens in a new tab)
- git.kernel.org/stable/c/e3f6745006dc9423d2b065b90f191cfa11b1b584 (opens in a new tab)
- ubuntu.com/security/notices/USN-7681-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7682-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7683-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7681-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7682-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7682-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7683-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7683-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7682-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7686-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7681-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7682-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7701-1 (opens in a new tab)