CVE-2025-38108 | net_sched: red: fix a race in __red_change()

In the Linux kernel, the following vulnerability has been resolved: net_sched: red: fix a race in __red_change() Gerrard Tai reported a race condition in RED, 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: 2025-07-03 Last update: 2025-12-16 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-38108 is rated Low Risk (34.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.06%). 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-2025-38108

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 2026-04-29 0.01% 0.06% +0.05%
2 2025-12-17 0.05% 0.01% -0.04%
3 2025-10-17 — 0.05% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38108

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.0 3.1 HIGH
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.0 5.9 [email protected]

Weakness enumeration for CVE-2025-38108

OS Trackers for CVE-2025-38108

vendor priority summary link
debian not yet assigned CVE-2025-38108 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-2025-38108
redhat medium — https://access.redhat.com/security/cve/CVE-2025-38108
suse medium CVE-2025-38108 severity moderate: SUSE including 483 source package names (2.1.3-6.67:kernel-default-base-6.4.0-32.1.21.10, 2.1.3-7.44:kernel-default-6.4.0-32.1, …), 1002 product×package rows across 201 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (201 product lines)): Fixed 697, Known Affected 231, Known Not Affected 53, First Fixed 21. https://www.suse.com/security/cve/CVE-2025-38108/
ubuntu medium CVE-2025-38108 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 169, ignored 164, not-affected 45, needed 25, needs-triage 2, pending 1. https://ubuntu.com/security/CVE-2025-38108

Affected software / configurations for CVE-2025-38108

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-2025-38108

URL Tags
https://git.kernel.org/stable/c/110a47efcf23438ff8d31dbd9c854fae2a48bf98 Patch
https://git.kernel.org/stable/c/2790c4ec481be45a80948d059cd7c9a06bc37493 Patch
https://git.kernel.org/stable/c/2a71924ca4af59ffc00f0444732b6cd54b153d0e Patch
https://git.kernel.org/stable/c/444ad445df5496a785705019268a8a84b84484bb Patch
https://git.kernel.org/stable/c/4b755305b2b0618e857fdadb499365b5f2e478d1 Patch
https://git.kernel.org/stable/c/85a3e0ede38450ea3053b8c45d28cf55208409b8 Patch
https://git.kernel.org/stable/c/a1bf6a4e9264a685b0e642994031f9c5aad72414 Patch
https://git.kernel.org/stable/c/f569984417a4e12c67366e69bdcb752970de921d Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Mailing List Third Party Advisory
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