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CVE-2025-21703

netem: Update sch->q.qlen before qdisc_tree_reduce_backlog()

Published: Feb 18, 2025Updated: Nov 3, 2025 Sources: CVE List NVD BDU csafCWE-416
7.8HIGH
NVD MITRE
EPSS Score
0.3%
Top 80.8%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

Description

In the Linux kernel, the following vulnerability has been resolved: netem: Update sch->q.qlen before qdisc_tree_reduce_backlog() qdisc_tree_reduce_backlog() notifies parent qdisc only if child qdisc becomes empty, therefore we need to reduce the backlog of the child qdisc before calling it. Otherwise it would miss the opportunity to call cops->qlen_notify(), in the case of DRR, it resulted in UAF since DRR uses ->qlen_notify() to maintain its active list.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:LAC:LPR:LUI:NS:UC:HI:HA:H
Exploitability
AV:LAttack Vector
Local
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
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Weaknesses

CWE-416

Affected Products

Linux
oss-projectaka the linux kernel
LinuxOn-premOS
Operating Systems / linux-distro
ООО «РусБИТех-Астра»
commercial·RUaka rusbitech-astra
Astra Linux Special EditionOn-premOS
Operating Systems / linux-distro
Сообщество свободного программного обеспечения
oss-projectaka fsf
LinuxOn-premOS
Operating Systems / linux-distro
АО «НППКТ»
commercial·RU
ОСОН ОСнова ОnyxOn-premOS
Operating Systems / linux-distro
Oracle Corp.
commercial·USaka oracle
Oracle ExadataOn-premDatabase
Databases / relational
and 1 more affected products View all →

Exploitability

Official Patch Available
Workaround Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Initial Access
Privilege Escalation
View detailed technique mapping

References

https://git.kernel.org/stable/c/1f8e3f4a4b8b90ad274dfbc66fc7d55cb582f4d5
git.kernel.org
https://git.kernel.org/stable/c/6312555249082d6d8cc5321ff725df05482d8b83
git.kernel.org
https://git.kernel.org/stable/c/638ba5089324796c2ee49af10427459c2de35f71
git.kernel.org
and 34 more references View all →
News mentions
Could not load news mentions.

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