CVE-2025-38083 | net_sched: prio: fix a race in prio_tune()

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.

Published: 2025-06-20 Last update: 2026-05-12 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-38083 is rated Low Risk (27.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.09%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-38083

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-16 0.02% 0.09% +0.07%
2 2025-12-18 0.06% 0.02% -0.04%
3 2025-11-22 — 0.06% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38083

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.7 3.1 MEDIUM
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.0 3.6 [email protected]

Weakness enumeration for CVE-2025-38083

GitHub Security Advisory for CVE-2025-38083

GHSA-pvq8-vg9v-94rw · Severity: medium — In the Linux kernel, the following vulnerability has been resolved: net_sched: prio: fix a race...

OS Trackers for CVE-2025-38083

vendor priority summary link
debian not yet assigned CVE-2025-38083 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. https://security-tracker.debian.org/tracker/CVE-2025-38083
redhat medium — https://access.redhat.com/security/cve/CVE-2025-38083
suse high — https://www.suse.com/security/cve/CVE-2025-38083/
ubuntu medium CVE-2025-38083 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, released 189, ignored 162, not-affected 52, needs-triage 2, needed 1. https://ubuntu.com/security/CVE-2025-38083

Affected software / configurations for CVE-2025-38083

Vendor Product Version Raw CPE
linux linux_kernel >= 5.0, < 5.4.295 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.5, < 5.10.239 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.11, < 5.15.186 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.16, < 6.1.142 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.6.94 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.34 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13, < 6.15.3 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 6.16 cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

References for CVE-2025-38083

URL Tags
https://git.kernel.org/stable/c/20f68e6a9e41693cb0e55e5b9ebbcb40983a4b8f Patch
https://git.kernel.org/stable/c/3aaa7c01cf19d9b9bb64b88b65c3a6fd05da2eb4 Patch
https://git.kernel.org/stable/c/4483d8b9127591c60c4eb789d6cab953bc4522a9 Patch
https://git.kernel.org/stable/c/46c15c9d0f65c9ba857d63f53264f4b17e8a715f Patch
https://git.kernel.org/stable/c/53d11560e957d53ee87a0653d258038ce12361b7 Patch
https://git.kernel.org/stable/c/93f9eeb678d4c9c1abf720b3615fa8299a490845 Patch
https://git.kernel.org/stable/c/d35acc1be3480505b5931f17e4ea9b7617fea4d3 Patch
https://git.kernel.org/stable/c/e3f6745006dc9423d2b065b90f191cfa11b1b584 Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Third Party Advisory
https://cert-portal.siemens.com/productcert/html/ssa-082556.html
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